Movatterモバイル変換

The mystery which has always surroundedthe work of the lead burner, like that of all otherhandicrafts outside of ordinary occupations, dissolvesunder the light of a full knowledge ofthe causes and effects that have a bearing uponit. While different works have treated on leadburning, it is the object of this special treatiseto explain fully in detail every part of the apparatusand fixtures in common use, as well as theirapplication, so that the careful reader may understandand acquire the art of lead burning byobserving scrupulously the rules laid down anddevoting sufficient time to practice to master it.This instruction, given by text and illustration,is only presented after the dangerous power ofhydrogen gas when misused is thoroughly impressedon the reader. It would be well for allwho hope to become lead burners to devote severalevenings, with an interval between, to athorough study of the chapters on hydrogen gasand its properties before taking any furthersteps. To those who have not had previous experiencewith chemicals and gases this preliminarystudy is indispensable for their own safety,for the successful operation of the apparatus andto insure satisfactory work. When fully familiarwith the properties of hydrogen gas and thenecessity of being careful when it is used littledifficulty will be experienced in acquiring a fullknowledge of the apparatus and fixtures. Theart of burning the lead can only be acquired bypractice, and either quickly or slowly, as the operatormay be quick and skillful in acquiring anyhandicraft. In addition to describing what hasbeen common practice for many years, the treatisecontains a description of a new machine andburner which has only recently become availableto lead burners. It also describes the method oflead burning with the use of illuminating gas anda soldering flux. A chapter is devoted to soft solderingand Britannia metal work, which islargely used in the equipment of bars and restaurants,the various joints being more easilymade with a blow pipe than by any other method.As the workman who hopes to profit by readingthis book can by a little negligence make a greatdeal of trouble for himself and others, cautionand great care are advised whenever he is atwork.

In compiling a treatise on the subject of leadburning too much stress cannot be laid upon thefact that the greatest care must be taken toobserve the smallest details and to follow carefullyevery suggestion in regard to safety. I amaware of the responsibility resting upon me inplacing this article into hundreds of hands, comparativelyignorant of the danger involved inhandling so much hydrogen, without thoroughlyinstructing them in detail as to its use. I maybe excused, therefore, if, for that reason, someof the explanations are so simple as to seemridiculous; but my aim is to present to the tradea treatise that can be relied upon to be free fromtheory that has not been thoroughly tried andtested, so that the beginner can be sure that, ifhe follows directions as printed, nothing but satisfactionto him can result.

Study the Chapter on Hydrogen Gas.

I cannot too strongly recommend that thebeginner study the chapter on hydrogen gasuntil the main points are memorized and clearly10understood. The experiments should be performedand the result carefully noted for futurereference before attempting to use the generator.It is time well spent to master the technical partsthoroughly before attempting the mechanicalpart. Then when a man takes up the mechanicalhe will do so with an intelligent understandingof what he is doing, and any little troublewhich may then arise can be quickly overcome.

Another thing to be observed is to avoid nervousness.A nervous person cannot do this workwith any degree of satisfaction, as it requires acool head and a steady hand and a vast amountof patience to burn the upright and invertedseams.

Lead Burning Explained.

Lead burning is the process of fusing twopieces of lead together without the use of solder.The process consists in melting the edges together,a drop at a time, and when done withhydrogen gas and the blow pipe is called the“autogenous process.” Lead can be fused withgasoline or illuminating gas by the use of thecompound blow pipe; but, as ordinary gases givean oxidizing flame and require a flux, it is notconsidered a practical method.

11

Fig. 1.—Lead Burning Apparatus.

12Lead is used extensively in lining tanks madeto contain pickle dips, hot cyanide solution, storagebatteries, acid tanks for manufacturing jewelryand water closet tanks, as water in manycases contains large quantities of lime and otherdeposits which rapidly destroy the solder usedon copper linings. Tanks used for the above purposesmust be lined with lead and the seamsburned, as acids attack the tin in solders anddestroy them. The demand for the work is rapidlyincreasing where it is introduced. I havedemonstrated to many manufacturers that this isthe cheapest method known, as it gives a permanentsolution of the problem how to keep a chemicaltank tight.

Method of Making Lead Lined Tanks.

The most common method resorted to inmany large factories is to make the tanks out ofvery heavy cypress lumber, free from any knotsor blemishes. The joints are carefully dovetailedand fitted together, and long bolts are used todraw the joints and keep them from leaking.Usually it takes from three to four days to completeone small tank, only to have it leak in a fewmonths; whereas the same tank can be built in afew hours of any cheap lumber, and then, whenit is lined with lead of a proper thickness and the13seams burned it will usually last for an indefiniteperiod, thereby saving floors and, many times,costly plating solutions.

The most common argument put forth bymanufacturers is that the bottoms of lead linedtanks are soon cut out, owing to dropping sharppieces of metal into them. This difficulty can bebest overcome by placing a slatted bottom ofwood in the tank, holding the same in place withstrips of sheet lead, one end of which has beenpreviously burned to the bottom of the tank.These strips are to be brought up through theslats and then bent over the top of them. Thiswill keep the wood from floating, and is the onlypractical way to do it, as the false bottoms soondecay, and can be easily removed and replacedby simply bending back the strips of lead.

General Remarks.

Soft solder, as referred to here, means solderthat melts at a temperature of 300 degreesor less, and is so called because of the low heatrequired to fuse the solder. It is used almostexclusively on the quick melting metals and compositions,such as block tin pipes and Britanniametal. It is also used by pattern makers in solderingwhite metal, as it requires but very little14heat to sweat it through heavy articles. It shouldnot be used to join any pipes which convey hotwater or other hot liquids, as it is readily actedupon and destroyed. (The composition of thesesolders is explained in a special chapter.)

The chapters on blow pipe work, also on barwork, will alone turn many dollars into the pocketsof the plumbers who have courage and ambitionto acquire this line of work. Many timessmall leaks occur in difficult places that can bereadily repaired by the use of the blow pipe anda common candle.

The lining of bars with Britannia metal iscoming more and more into general practice, andit usually requires a specialist in this line to dothe work. The soldering of this metal with ablow pipe and an alcohol torch is an easy matter,and is described in a special chapter.

There is no reason why this work should notbe done by a plumber, particularly in small citiesand towns, and to aid such as have not had theopportunity to familiarize themselves with suchwork I append such diagrams as may seem usefuland necessary.

The apparatus used for lead burning is illustratedin Fig. 1. It consists of a gas generator,A; an air holder, B, and pump, C; mixing fork,e,and necessary cocks,f andg; combined scrubbingcup and fire trap,h; blow pipe and tips,i.

The generator consists of an acid chamber,j,and a gas chamber,k. These are connected withan acid supply pipe,l, which conducts the acidfrom the acid chamber to the gas chamber, andalso serves as a balance pipe.

This feature makes the generator automaticin its action, for as soon as the gas in the gaschamber gets up sufficient pressure, the acid inthe gas chamberk is driven slowly back throughthe acid supply pipel and up into the acid chamberj, where it is held until gas is used. Whenthe acid descends and submerges the zinc moregas is generated, replacing that which has beenused. This form of generator will never blowacid like the floating generator.

The requirements of a hydrogen generatorfor lead burning are that it should be safe, economical16and automatic in its action. It must beso constructed that it will generate gas enoughto keep the supply constant, and deliver it at sufficientpressure to keep the flame steady. It mustalso be provided with a combination fire trap andscrubbing cup. This will prevent the explosionof the generator by firing the gas in the hose.This trap must be partly filled with a solution ofblue vitriol to act as a precipitation cup. (Thisis treated under the head of “Scrubbing Cup.”)

The chief danger with an apparatus of thissort is its liability to accident by the careless useof the gas, and, as a mixture of hydrogen and airis very explosive, great care must be taken toexhaust all the air in the generator and tubesbefore attempting to light the gas at the blowpipe. The only way to make sure that the air isexhausted is to test the gas, as described underthe head of “The Flame and Its Management.”

A Few Cautions.

It is a very sensible idea to keep spectatorsaway from the generator, as they are very aptto strike matches or tread on the tubes, in spiteof warnings to be cautious, for if there shouldbe a leak, even so slight as to be hardly detected,it would cause a violent explosion, and as hydrogen17is both odorless and colorless, this couldeasily happen without being noticed. This isprobably the origin of the apparent secrecy withwhich a lead burner usually surrounds himself.

If an explosion should occur in the tubes andthey should catch fire, the operator must havepresence of mind enough to reach the gas cockon the generator and close it. If gas explodesin the generator, all that can be done is to dodgethe flying pieces and make a new generator. Ifsuch an incident should occur and vitriol shouldspatter on the person doing the work, or his assistant,a solution of bicarbonate of soda or commonwashing soda should be at once applied tothe wounds. If that cannot be procured, greaseor oil of some kind should be used without delay,rubbing it on the spots where the acid burns, andthis will neutralize the acid and so prevent it doingfurther damage. There should be no troubleof this sort in the hands of a careful workman.The watchword should be, “Test the gas beforeusing.” If this is done, explosions will neveroccur.

This element was discovered by Cavendish in1766, and was called by him inflammable air.The name hydrogen is derived from two Greekwords, one signifying “water” and the other“to generate,” on account of its forming waterwhen burnt. It occurs in its free state in thebases of volcanoes, and by the aid of the spectroscopehas been detected in the sun and stars.It chiefly exists in combination with oxygen aswater, and is an important constituent of allvegetable and animal substances.

Hydrogen is obtained by the decompositionof water in various ways. On a large scale,nearly pure hydrogen may be prepared by passingsteam over charcoal, or coke, heated to a dullredness. If the temperature be kept sufficientlylow hydrogen and carbon dioxide will be the soleproducts, and the latter may be removed by causingit to traverse a vessel filled with slaked lime,but if the temperature be allowed to rise too high,or an excess of air be admitted, carbon monoxide19is also produced, and cannot be removed fromthe mixture.

Pure hydrogen is a colorless, odorless, transparentand tasteless gas, and has never beenliquefied. It is very slightly soluble in water. Itis the lightest of all known bodies and is not poisonous,although it cannot support life, and ifmixed with a certain proportion of oxygen it canbe breathed for a considerable length of timewithout inconvenience. It is highly inflammable,and burns in the air with an almost colorless, nonluminousflame, forming water. A burning taperis extinguished when plunged into hydrogen, andall bodies which burn in the air are incapable ofburning in hydrogen.

Hydrogen does not spontaneously enter intoreaction with any of the elements, although it hasa powerful affinity for several of them. Thus,when hydrogen and oxygen are mixed nothingoccurs, but if a lighted splint is introduced a violentexplosion ensues, water being produced.Similarly chlorine and hydrogen are without actionupon each other in the dark, but if the mixtureis exposed to a bright light, or if heated bythe passage of an electric spark, the gases are atonce combined with explosive violence, forminghydrochloric acid.

20Hydrogen is usually prepared by the action ofzinc or iron on a solution of hydrochloric or sulphuricacid. All metals which decompose waterwhen heated readily furnish hydrogen, on treatmentwith hydrochloric or sulphuric acid. Manyother metals enter more or less readily (althoughnone so readily) into reaction with these acids.Also, many other acids than sulphuric or hydrochloricacids may be used, but none acts so quickly.In all cases the action consists of the displacementof the hydrogen of the acid by the metal employed,and if the acid is not one which can enterinto reaction with the displaced hydrogen, thelatter is also evolved as gas.

If pure gas is required it is necessary to employpure zinc or iron, as the impurities in theordinary metal communicate an extremely disagreeableodor to the gas.

The pure gas is not absolutely essential forlead burning, and owing to their being muchcheaper, and also on account of their increasedquickness of action, the commercial qualities ofsulphuric acid and zinc are employed in the generatordescribed.

The commercial zinc is known as spelter andis sold in pigs or blocks, which are easily brokeninto fragments, like stove coal, with a heavy hammer.21The commercial sulphuric acid is known asoil of vitriol and is sold by the pound. The acidcannot be employed in its pure state, but must bereduced with water in the proportion of one partof acid to seven parts of warm water. They mustbe mixed by adding the acid slowly to the water;never the water to the acid. The combination ofacid and water enters at once into reaction andalways generates heat, and the result of addingwater to acid would be small explosions. Therewould be danger of the acid flying on one'sclothes or into the eyes. The mixture shouldnever be stronger than six parts of water to oneof acid.

The beginner will observe from the abovethat the generator cannot be crowded by makingthe acid solution strong. Hydrogen is a peculiargas and also a dangerous one for one ignorantof its peculiarities to experiment with, and inorder to thoroughly understand it the followingexperiments should be demonstrated, which canbe done with little expense. The beginner shouldnote the result of each experiment as demonstrated,and carefully commit the same to memoryfor future reference.

Experiment 1.

Test for Hydrogen.—Fill a small jar or widemouthed bottle with hydrogen. This is done by22first filling the bottle with water, inserting theend of the tube from the hydrogen generator,having first exhausted the air in the tube, thenquickly inverting the bottle and placing the neck,Fig. 2, in a pan of water (A); the water will stayin the bottle. Now turn on the hydrogen. Thegas, being lighter than water, will rise to the topof the bottle (B), drive out the water, and replaceit with pure hydrogen, which should be free fromair. Remove the bottle from the pan of water,keeping it inverted. Thrust a lighted splint intothe bottle. The gas will light and burn at themouth of the bottle. If the splint is thrust farinto the bottle it will go out. Drops of water collectin the bottle. Burning is a union with oxygen;therefore, the burning of the hydrogenshows that it has an affinity for oxygen. Thesplint goes out because the hydrogen does notsupport combustion.If no air is allowed to getinto it the gas cannot burn or explode.

Fig. 2.—Experiment No. 1.

Fig. 3.—Experiment No. 2.

Proving That Hydrogen is Lighter Than Air.—Bringan inverted bottle of hydrogen close toan empty bottle, also inverted, Fig. 2. Graduallytip the bottle containing hydrogen (A) until it isbrought to an upright position beneath the emptybottle. Test the bottles for hydrogen. The hydrogenwill be found in the bottle (B) that wasat first empty, proving thathydrogen is lighterthan air, as it has risen in the empty bottle, displacingthe air that was in it. If the bottle of24hydrogen is left in an upright position withouta cover for a few moments the gas will entirelydisappear.

Experiment 3.

Fig. 4.—Experiment No. 3.

The Effect of Mixing Hydrogen and Air.—Halffill a bottle with water and invert it in a panof water, Fig. 3, leaving the upper half filled withair. Displace the air in the bottle with hydrogen,then thrust a lighted splint into the bottle, andthe gas will light with an explosion. When thebottle was half filled with water the other halfwas air. The hydrogen took the place of thewater, so that the bottle contained equal quantitiesof hydrogen and air. When the hydrogenwas lighted it combined with the oxygen inthe air. The union of the two gases caused the25explosion, proving that the combined gases arevery explosive.

Experiment 4.

To Make Hydrogen From Water.—Drop apiece of potassium into a little water and coverit. The potassium floats on the water and soonburns. Potassium acts vigorously on cold water,setting free hydrogen, and unites with parts ofit to form “caustic potash.”

The construction of the generator is the firststep in the mechanical part of the business, andto simplify this a complete set of reference drawingshas been constructed and is herewith given.The assembling of the parts should be clear, withthe assistance of the perspective drawing of thecompleted apparatus, and any mechanic of ordinaryability should be able to construct this generatorwithout any trouble. The following billof material should first be purchased:

One ⅞-inch whitewood board 10 inches wide and 8 feet 6inches long.

One ½-inch whitewood board 12 inches wide and 4 feet 6inches long.

One piece of 6-pound sheet lead 3 feet wide and 6 feet 6inches long.

Three ⅛-inch female hose end gas cocks.

One piece of ⅛-inch brass tubing 2 feet long.

One foot of ¼-inch lead pipe.

One 4-inch charging screw.

One 1¼-inch cleaning screw.

Making the Charging and Cleaning Screws.

These goods can be readily purchased fromdealers, with the exception of the charging and27cleaning screws. They can be made in any brassfoundry. The only difference between the chargingand cleaning screws is the size. The chargingscrew, Fig. 5, should be at least 4 inches indiameter, or large enough to pass the handthrough, while the cleaning screw should be 1¼inches in diameter, or large enough to pass overa 1-inch pipe. A piece of sheet lead is fitted intothe cover, as shown ata, to protect the metal fromthe acid. Soft putty is used for a packing, asshown in Fig. 5.

Fig. 5.—The Charging Screw.

The best, although a more expensive, chargingscrew is shown in Fig. 6. As will be seenfrom the cut, it consists of a base,k; cover,d;clamp,e, and screw,f. The base is simply aplain iron or brass ring, 4 inches in diameter, ⅛inch thick and 1 inch high. The bottom is to be28faced smooth, while the top is recessed 3-16 inchdeep to receive the sheet lead and packing ofputty, as ata. Two nubs,b andb, are cast onopposite sides, as shown, to act as grips for theclampc. These nubs are ¾ inch long and projectout from the body of the base ¼ inch, and aremade sufficiently strong to stand the strain of thescrew. The coverd is made of the same materialas the base, the center being raised, as shown,to give it strength. Cast directly in the centerand on the top is the nube, ⅝ inch high and ⅝inch in diameter. This is drilled to receive the⅜-inch screwf. A groove 1-16 inch wide and1-16 inch deep is cut all around the bottom ofthe screw, as shown ati. A hole is then drilledthrough the side of the nube, and in line withthe sloti. A pin can then be driven through thehole and will pass through the sloti, making aswivel joint that will connect the cover and screwtogether. The screwf is made of ⅜-inch roundiron sufficiently long to give an action of about1 inch. The top atn is filed square to receive awheel such as is used on a common gate valve. Along thread should then be cut on this screw.The clampc is made a half circle in shape, so asto clear the cover with ease. It should be ¾ inchwide, flat on the under side, while the top side29should have a rib cast on it to prevent springing.The top atg should be reinforced with metal andmade heavy enough to stand drilling and tappingto receive the screwf. A wood pattern can bemade for these parts, and they can then bemolded in any brass or iron foundry. In makingthe patterns they should be cut down as muchas possible, so as to make the finished article aslight as is consistent with the strength required.The same directions will answer for the cleaningscrew. The hole to receive the sheet leadover the cleaning screw should not be over 1½inches in diameter, and the rest of the screwshould be made in proportion to this hole. Theadvantage of this screw over others is that itdoes not wrench the sheet lead in making it up,and, owing to its construction, it is always sureto make a tight joint without straining the generator.

Fig. 6.—The Best Charging Screw.

The frame can be made of galvanized iron,but wood is much superior, as it retains the heatgenerated in the gas chamber much better. Tomake the frame take the ⅞-inch board and cutoff two pieces, 10 inches square, A and B in Fig.8; 5 inches from one side and 2 inches from theback of one of these pieces bore a 1½-inch hole,C, and countersink it. This is for the acid supplypipe to pass through. These pieces are intendedfor shelves upon which to rest the acidand gas chambers. Cut the remaining board intotwo pieces 38 inches long. Lay these two boardstogether. Five inches from the side and 3 inchesfrom the bottom bore a 1½-inch hole,d. Thensaw out a V-shaped piece, Fig. 7. This will formthe legs of the generator.

31

Fig. 7.—Making the Acid Chamber.

32Take a square, and 12 inches from the topof these boards draw the linese ande. Twenty-twoinches below these lines draw the linesf andf. These lines represent the tops of the shelves.The shelves should be nailed or screwed intoplace. The shelf B should be placed on the top,keeping the hole C to the back. Take the ½-inchboard and cut two pieces to measure 12 × 13inches and two pieces 11 × 12 inches. Theseform the sides of the acid and gas chambers. Thetwo 12 × 13 inch boards form the sides of theacid chamber and the 11 × 12 inch boards thesides of the gas chamber.

Directly in the center and 1¾ inches fromthe bottom of one of the 11 × 12 inch boardsbore a 1½-inch hole. The remaining pieceshould be sawed out, leaving a hole atg. Thisis so that the board can be removed in case of aleak without disturbing the cleaning screw.These pieces should be fitted to their places withround head screws, and if properly done willform an acid chamber which will measure 10 ×10 × 12 inches, and the gas chamber will measure10 × 10 × 10 inches. The acid chamber mustbe larger than the gas chamber, to allow the fullcharge of acid to be used without overflowing.

33

Fig. 8.—Making the Shelves and the Perforated Bottom.

34Now fit the sheet lead. Six-pound is plentyheavy for this generator and will last a lifetime.Cut it as shown in Fig. 8, A and B. Form thelead so that the seams when finished will comeon the outside, as in case of a leak in a seam itcan then be easily repaired by removing one of theboards. The projecting edges of lead should bedressed over the edges of the top to protect thewood from the acid, but do not fasten them, asthe tanks will have to be removed and the seamsburned.

Now cut the piece of lead C to form the topof the gas chamber. None is needed for the acidchamber, as it must be left open so that no resistancewill be offered to the action of the gason the acid. Five inches from the side and 2inches from the back of this piece cut a hole,d,Fig. 8, 1¼ inches in diameter, and dress it upwith the bending iron to 1½ inches in diameter,taking care to preserve the thickness of the metal.This is for the acid supply pipe to pass through.

Three inches from the side and 3 inches fromthe front cut a ⅛-inch hole,e. This is the gasoutlet. Three and one-half inches from the oppositeside and 4 inches from the front cut theholef, 2¾ inches in diameter. Dress this up andover the flange of the charging screwa, Fig. 6.This may seem a difficult thing to do, but leadmust be worked slowly. Heating the lead whiledressing it will help wonderfully. If it is notpossible to make a good job in this manner, thencut the hole 4 inches in diameter and burn in a35collar sufficiently big to dress over and cover theflange of the screw. This is to prevent acid fromcoming into contact with the screw and destroyingit. Treat the cleaning screw in the samemanner. The location of this screw is in thecenter and as close as possible to the bottom ofthe gas chamber, as shown in Fig. 8 atj.

Fig. 8½.—Showing the Perforated Spelter Shelf in Place in the Generator.

It is necessary to have a false perforated bottomin the gas chamber to rest the zinc upon andalso to keep it above the solution. To make andsupport this bottom take a piece of sheet lead14 inches square, as shown in Fig. 8, andform it in the shape of a pan, which willdrop easily into the gas chamberk, Fig.8½. A piece of 1½ or 2 inch lead pipe, 2inches long,n, should be burned on the center36of the false bottom, to prevent the center fromsagging with the weight of zinc. Then punchthe bottom O, Fig. 8, full of ¼-inch holes. A1½-inch hole,y, should also be cut in line withthe holes for the acid supply pipe.

Remove the tanks and burn the seams. Placethe tanks back in place. Then take a piece ofthe ⅛-inch brass pipe, 1½ inches long. Cut athread on one end, tin the other end, and burnit to the top of the gas chamber ate; also thecollar for the charging screw. Then place theperforated bottom in the gas chamber, takingcare to keep the holes for the acid supply pipein line. Do not make any mistake in putting inthis bottom. Its use is to act as a shelf to holdthe zinc, and if put in properly it will holdthe zinc about 2 inches above the real bottom.The top of the gas chamberc should then beburned in. Now by measuring find the exactlength of the acid supply pipe, Fig. 7,i. Thispipe should extend from the bottom of the acidchambero to the bottom of the gas chamberp,as shown in Fig. 7. From one end of this pipeseveral V-shaped pieces should be cut,p, about1 inch deep.

This is one of the most particular parts ofthe apparatus, as this is where the automatic37action comes in, and great care must be taken incutting these holes not to have any of them comecloser to the perforated bottom than 1 inch. Ifthis were not observed the acid would be constantlyin contact with the zinc, and would rapidlyget up pressure of gas sufficient to blow acidout of the upper tank, and the extra gas wouldescape through the acid supply pipe in blows. Infact, it would make the generator useless. Thisis the trouble with the French apparatus. Theacid, having no place to expand in, is constantlycoming into contact with the zinc, and unless thegas is being used as fast as generated it willblow acid out of the acid holder, making a badmess, besides being very wasteful.

Now flange the other end of this pipe to fitthe countersunk bottom of the acid chamber.Place the pipe in position and burn it to the bottomof the acid chamber and to the top of thegas chambern, Fig. 7. One of the ⅛-inch gascocks should be screwed on the brass nipple ontop of the gas chamber. This will complete thegas generator. It will make a better job if theback of the generator be boarded tight and adoor made to fit the space between the bottomof the acid chamber and the top of the gas chamberin front. It is very convenient to have it38fixed in this manner, as in shipping it from onepoint to another the tubes and other incidentalscan be placed in the space so made and shippedwith safety. There is no objection to the acidand gas chambers being made in the shape ofcylinders, instead of square, if so desired, but ifmade circular they should be made to fit theframe tightly to prevent jarring and eventuallybreaking the seams.

In towns supplied with illuminating gas it isa comparatively simple operation to burn the leadlining for the generator, but for the convenienceof those who cannot obtain gas it is necessaryto give some method by which the generator canbe burned. The method described will answerfor illuminating gas as well as for gasoline.

To generate gas from gasoline is a simpleoperation. To do this, take a common 1-gallonoil can, remove the top of can screw and punch a¼-inch hole in the center of it. Then make atube of tin that will pass through this hole, sufficientlylong to extend half way to the bottom andproject 2 inches outside of can screw, and solderthis tube in place. This projecting tube is forthe purpose of connecting to the air holder. Removethe spout of the can and replace it with oneto which the hose can be connected. Now fill thecan two-thirds full of gasoline, but not fullenough to cover the gas outlet, else it would belikely to force gasoline out instead of gas.

40After this is done, screw the can screw inplace, the long end of the tube extending into thegasoline, as shown inj, Fig. 9. A hose connectionis now to be made with an air holder. As itis necessary to have an air holder both for thisprocess and the hydrogen gas process, methodswill be described for making air holders whichcan be used for either.

Fig. 9.—Gas Apparatus for Burning the Generator.

Air Holders.

Different lead burners have different viewson this subject. Some prefer the bellows, with41a contained air holder; some the air holder builtlike a gasometer, while others use an air holdersimilar to the generator in construction. Theseall have their advantages. For my part, I ownand use all three.

The advantage of the bellows is that it can beeasily transported and does the work perfectly,but it requires constant pumping, which soontires the helper, and for that reason could notbe used on jobs requiring more than four or fivehours' labor.

The gasometer style of air holder is theeasiest to use, if one does not employ a helperand has a large amount of work to do. Thepressure can be regulated to suit the work byplacing one or more weights upon it until the desiredpressure is obtained. It does not requirepumping up more than three or four times a day,which is its principal virtue. It is a perfect shopapparatus. Its disadvantage is that it requiresa large quantity of water to fill it, which is notalways available, and when full it is so heavythat it requires a truck to move it around.

By far the best air holder is the one shown aspart of the apparatus in Fig. 9, and illustratedseparately in Fig. 10. This only requires a fewpails of water to fill it, and the exact pressure of42the gas can be had by building it the same hightas the hydrogen gas generator. It does notrequire constant pumping, and I recommendthis air holder for general use, as possessingmore advantages, with less trouble, than anyother air holder in use. However, all three willbe described, and the beginner can make the onemost suited to the material available.

Air Holder No. 1.

The beginner will notice in Fig. 10 that thisair holder is so constructed that it gets its airpressure direct from the head of water, and alsothat this pressure can be varied by making theconnecting piece of pipe longer or shorter, asmay be desired. Of course, the pressure willvary slightly as the water descends into the airchamber, but not enough to make it objectionable,as it will be the helper's duty to watch thewater line and renew pumping as often as thewater falls below a certain point.

To make this holder, a tank,a, Fig. 10, 12inches high and 18 inches in diameter, should beconstructed of galvanized sheet iron. On thistank double seam a flat bottom. The top mustbe raised slightly, as shown, to give it strength.This can be done with the raising hammer, or it43can be done by making the circle for the top ¾inch larger than the bottom, then making a cutto the center. It can then be drawn together andriveted in any desired pitch. A hole must bepunched in the center of this top large enough toreceive a 1-inch galvanized pipe,b. Six inchesapart and 2 inches from the edge punch twoholes,c andd, large enough to receive pieces of⅜-inch galvanized pipe. This top should thenbe fitted and placed on the body of the tank.

Fig. 10.—Air Holder No. 1.

44Take a piece of 1-inch galvanized pipe,e,sufficiently long to touch the bottom and projecting1 inch out of the top of the tank, cut athread on the projecting end and drill the otherend full of ¼-inch holes,f, to the hight of 1 inch,to allow the water to flow freely. This pipe restson the bottom of the lower tank and carries theweight of the upper tank. Solder this pipe inplace. Then take two ⅜-inch nipples, 1 inchlong, and solder them into their places, and onthese nipples screw two ⅜-inch hose end gascocks,c andd. One of these cocks is for the purposeof connecting to the air pump, and the otherto the mixing cock. As close as possible to thebottom of the tank solder in a ½-inch coupling,g. Into this coupling screw a plug. This is forthe purpose of draining the tank when out ofuse.

Now make another tank,h, 19 inches in diameterand 11 inches deep, the top to be left openand wired with a heavy wire. Double seam aflat bottom on this tank. Directly in the centerof this bottom punch a hole large enough to receivea 1-inch coupling. Then cut a 1-inch couplingin half and solder it into this hole, putting45the thread side down and leaving it as near flushwith the outside of the tank as possible, so thatif it is desired to move the air holder to and froma job it can be taken apart and the lower tanknested in the upper tank, making a compact bundleand reducing the danger of damage by carelesshandling.

To connect these tanks, all that is required isa piece of 1-inch iron pipe,h, 12 inches long, witha coupling on one end. To operate this airholder, close the two air cocks on the lower, orair, tank; then fill the upper tank nearly full ofwater, taking care not to put too much in it, orit will overflow the lower tank and get into thetubes, and if this happens the tubes will have tobe removed and hung up to dry, or drops ofwater will be blown into the blow pipe and extinguishthe flame. It is then ready for use. Theair in the air chamber is compressed by theweight of the water in the upper tank, and if thewater line is at the same hight as the acid line inthe hydrogen gas generator the pressure of airmust be the same as the pressure of gas. As airis used the water descends through the pipe andwill gradually fill the lower chamber. It can thenbe forced back into the water chamber by attachingthe air pump to the cockh in Fig. 9, ord in46Fig. 10, without disturbing the gas or in any wayinterfering with the operator. To connect withthe cockh in Fig. 9 it is only necessary to disconnectone line of hose and connect the pump;then close the other cock and work the pump untilair bubbles up in the upper tank; then shut thecock, remove the pump and connect the hose tothe gasoline can, open the cocks and the apparatusis ready for use.

Air Holder No. 2.

To make the air holder shown in Fig. 11, takea sheet of No. 26 gauge galvanized iron 30 incheswide. Make it into a cylinder 26 inches in diameter,double seam a flat bottom on it, and wirethe top with ¼-inch iron rod, which will make itstiff enough to withstand the pressure of water.Close to the bottom and 3 inches apart punchtwo holes,a andb, large enough to receive ⅜-inchgalvanized pipe couplings. Solder thesecouplings in place.

On the inside of this tank and into thesecouplings screw two pieces of ⅜-inch pipe 4inches long with elbows pointing straight up.Into these elbows screw two pieces of ⅜-inchpipe long enough to come flush with the top ofthe tank F. On the outside of the tank and into47the ⅜-inch couplings screw two ⅜-inch nipples2 inches long, and on these nipples screwtwo ⅜-inch hose end gas cocks.

Fig. 11.—Air Holder No. 2.

Now, with the same sized sheet iron, makeanother tank 2 inches smaller in diameter thanthe first tank. This should have a flat bottom,and be wired as previously described. Then takefour strips of sheet iron 30 inches long and 2inches wide, and form each into V shape lengthwise.48Lay off the circumference of this tank infour equal spaces. One side of the V-shapedpieces should then be soldered on at each space.The other side should be left loose to allow foradjustment. These pieces form the guides to theupper tank and prevent it from tipping sidewaysand binding. Two of the guides are shown inthe illustration, Fig. 11.

The lower tank should now be filled aboutone-third full of water. The upper tank shouldthen be inverted and placed in it. The air pumpmust then be connected to one of the ⅜-inchcocks with a short piece of hose, and the airshould be pumped into it until the upper tankrises to its highest level.

The pressure in this form of air holder mustbe regulated by weights, and to secure 1 poundof pressure it is necessary to place weights equalto 1 pound for every inch in area contained inthe opening in the upper tank. Two drop handles,such as are used on heavy milk cans, shouldbe riveted and soldered on the sides of the tankto facilitate moving it about.

Air Holder No. 3.

Fig. 12 is a cut of a bellows with a containedair holder. It is not practical to try to makethis article, as it can be purchased from any49plumbing supply house and is not expensive. Itis used principally by dentists, but it is also usedin laboratories to supply air to the compoundblow pipe. It consists of a small bellows heldfrom the floor on iron legs, with a spring insidethe bellows to hold them open, and has a rubberbag fastened to the under side to hold a smallsupply of air. The rubber bag is incased in astring net to prevent it from becoming inflatedtoo much and bursting. This bag servesto equalize the pressure. The size known asNo. 10 A will supply 75 cubic feet per hour at apressure of 1½ pounds to the square inch, whichis sufficient for lead as heavy as 24 pounds. Forthe light weight leads the pressure can be reducedby pumping lightly and not filling the bagmore than half full.

Fig. 12.—Air Holder No. 3, Combined with Bellows.

50Any of the three described air blast arrangementswill answer the purpose, so it is immaterialwhich is used, and it is left to the discretion ofthe beginner to obtain whichever is the most convenient.

The Blow Pipe.

Next comes the blow pipe. The only practicalcompound blow pipe on the market is shownin Fig. 13, and is known as Walmsley's. This isa modification of the Bunsen burner, and consistsof a bent blow pipe with the air tube in thecenter, as shown in Fig. 14. It is a perfect workingblow pipe in every respect, and I should adviseevery one interested in the work to purchaseone. For while seams cannot be burned with itin any other position than horizontal, it will befound useful in lengthening traps or lead bends,for which purpose it is well adapted and can beput into instant use, thereby saving its cost manytimes over in wiping solders.

Fig. 13.—The Walmsley Compound Blow Pipe.

With illuminating gas it is only necessary toconnect the gas jet to the compound blow pipewith the hose and regulate the supply of gas withthe gas cock. The air inlet is then connected tothe air holder, or air may be supplied with themouth, but good results are not obtained withthe mouth, as only a good blow pipe solderer cankeep up the blast necessary. To burn the seamsuse the same flux and follow directions givenfor gasoline gas.

Fig. 14.—Sectional View of Walmsley's Blow Pipe.

Making the Gasoline Gas for Burning the Generator.

With a piece of ¼-inch hose connect the topof the can C, Fig. 9, with the air holder D, thenconnect the spout or gas outlete of the can tothe gas endf of the compound blow pipe. Theair outletg of the compound blow pipe shouldthen be connected to the remaining cockh, in theair holder. If the bellows is used, it will be necessaryto connect the air with ¼-inch tee,m, in52which three short nipples have previously beenscrewed.

The apparatus is now ready for use. Gasolinebeing really a liquid gas, it takes its firstopportunity to assume its natural shape. Thenatural way to convert gasoline into gas is bysimple evaporation. So taking advantage of thisfact, the action will be thus: By forcing air intoand through a body of gasoline sufficient of thegasoline is taken up to form a dense vapor, whichwill light and burn at the jet, similar to illuminatinggas. With the admixture of air in thecompound blow pipe, it gives a flame of very intenseheat. But, in common with illuminatinggas, it is so rich in carbon that it gives an oxidizingflame, and makes it necessary to use a flux,which should be Yager's soldering salts mixedas per the directions on the bottle. If this is difficultto procure, a good substitute can be madeby mixing equal parts of powdered borax and salammoniac in a little water.

To operate this device the air should beturned on the gasoline and lighted at the jet.The air should then be admitted gradually untilthe flame is brought to the proper size and condition,indicated by its being blue and pointed. Iftoo much gas is admitted the flame will be yellow53and will blacken the work by depositing acoat of soot on it. If too much air is admittedthe flame will be ragged and noisy, and the temperaturewill be too low to heat the metal. Theflame is at its best heat when it burns with apale blue color which does not show any yellowstreaks.

Before attempting to burn the generator thebeginner should practice on pieces of sheet lead.It is next to impossible to burn seams in anyother position than horizontal with this flame, asit rapidly oxidizes the lead, and in spite of allprecaution the lead will become unmanageablein upright seams, so that the beginner wouldwaste time in practicing on seams in any otherposition than horizontal. If directions have beenfollowed in cutting the lead for the generator theseams will occur only in that position.

To burn the generator the seams should beshaved clean, both on the under and upper sides,for a distance of ⅛ inch, making a seam ¼ inchwide, taking care to have the lead seams lie closeto each other, for, if they do not, this flame willcause the edges of the lead to spread away fromeach other and leave a hole that is difficult topatch.

Now apply the flux with a small brush. When54the flame is in working order bring it quicklyto bear on the end of the seam nearest you to beburned. When it starts to fuse draw the flameas quickly away, always drawing it to one side,and from the upper to the lower sheet. Themelted drop will follow the flame and unite withthe melted drop on the lower sheet.

It is necessary to have the shave hook nearat hand, so that, in case of oxidizing when fusing,the melted drop can be broken up and allowedto flow in place.

With a little practice and patience the generatorcan be burned all right in this manner. Thisgas is perfectly safe and can be handled with impunity.This method would, of course, be impracticableto use on a job of any size, but I haveused it several times where nothing else couldbe obtained, and have always had very good successwith it.

We now assume that the generator is chargedand the rest of the apparatus is finished andready for use, so we will proceed to connect itup ready for a trial.

About 30 feet of ¼-inch heavy rubber tubingshould be procured. This hose should beheavy enough to allow of its being pulled aroundwithout kinking and shutting off the supply ofgas. A piece of this hose 5 feet long should beslipped on the gas cock M on the generator,shown in Fig. 1, and then slipped over the gasinlet tube of the scrubbing cupn. One must besure that this is connected to the gas inlet tube,which is the tube that dips under the water inthe scrubbing cup.

With another 5-foot piece of hose connect thegas outlet of scrubbing cupo to the right handcock on the mixing forkf. Always connect thegas on the same side so as to avoid confusionof cocks. Then with a 10-foot piece of hose connectthe air cock on the air holderp or bellows56to the remaining cock on the mixing forkg. An8-foot piece should be connected from the gas outleton mixing forke to the blow pipei.

These tubes must fit tight to prevent any possibleleak of gas, and if they do not they shouldbe tightened on with pieces of wire. The remainingpiece of hose can be used to connect the airpump C to the air inlet cocks on the air holder,but if the bellows are used this will not be needed.

Now place in the scrubbing cup a half dozenpieces of blue vitriol, or copperas, as it is commonlycalled. Then pour in clear water until itflows out of the trap screwz. This screw canbe made tight by using for packing a piece ofwicking which has been saturated with tallow.After preparing the apparatus as above, refer tothe cut of the complete apparatus and comparethe connections on the cut with those made fromthe above directions, to make positive that theyare right. If they agree, the apparatus is nowready for use.

Testing the Apparatus.

It is necessary to test the generator for leaks,as a small blow hole may sometimes be left insome of the seams or the cocks or cleaning screwsbecome defective.

To do this, first close the gas cock on the top57of the gas chamber and make up the cleaning andcharging screws, which must be set on a bed ofsoft putty. Then fill the acid chamber full ofhot water, first measuring the water so as to ascertainjust how much solution is required in proportionto the amount of water, as it takes thesame quantity at all times. Allow it to stand fora few moments, then mark the water line with apencil or nail, when it should be left standing foran hour. The water should stay at the mark indicatedfor an indefinite time. If it sinks duringthis test it shows that there is a leak in the generatorand it must be located and repaired.

Fig. 15.—Mixing Fork.

To locate the leak the gas cock should be58opened and the water allowed to run into the gaschamber. If this does not show the leak, forcethe water back into the acid chamber, which isdone by attaching the air pump to the gas cock.Then taking a piece of soap and making a stifflather, daub it over the cocks and cleaning andcharging screw. When the leak is found theescaping air will cause bubbles to be blown. Ifthe leak does not become apparent after theabove process, the side boards of the generatorshould be taken off and the operation repeatedon the seams.

Under no circumstances must the apparatusbe left until there is absolutely no doubt as to itsbeing perfectly tight, as a slight leak would belikely to cause a disastrous explosion and injureor probably blind the operator. Flying vitriol isnot a very pleasant thing to get in one's eyes.

The apparatus should be frequently tested inthis manner: Before drawing off the water it isdesirable to learn what amount of gas pressurethere will be when the generator is charged, sothat the pressure of air and gas can be equalized.The mathematical rule for this is to multiply thehead in feet by 0.434, and the result will be thepressure in pounds; or an approximate way ofdetermining the pressure is to allow ½ pound59pressure for every foot of head. For example:The hight of liquid in the generator measuredfrom the bottom of the acid supply pipe to thetop of the water or acid line, when at its highestlevel, would be 3 feet. Allowing ½ pound forevery foot in hight would give a pressure of 1½pounds, which is slightly in excess of the mathematicalrule, which is 3 × 0.434 = 1.302, or 1pound 4 ounces, but to be accurate it is well toattach a mercury gauge to the gas cock. Notethe hight of the column of mercury. Then attachthe gauge to the blast apparatus, and if thefloating air holder is used, sufficient weight mustbe put on the top of air holder to raise the columnof mercury to a point not quite as high as isindicated by the generator. These weights canthen be weighed and a similar weight made oflead to correspond, which can be kept for permanentuse. If the bellows are used, the sizespecified should be obtained, and the pressurewill be all right for this size generator withoutfurther trouble. If the air holder indicated byFig. 8 is used, all that is necessary is to makethe hights of the water line in both generator andair holder equal, and the pressure must be thesame.

Fig. 16.	Fig. 17.
Mixing Forks.

60The reason that the air pressure should notbe heavier than the gas pressure is that if theair were the stronger there would be danger ofthe air working back into the gas tube and causingan explosion in the tubes; consequently it iswell to note this point carefully. Many lead burnerswill say that the pressure of air is of no consequence,and all that is required is a sufficientsupply; but my experience and experiments haveconvinced me that when the pressures of air andgas are nearly equal the best results are obtained.

The Mixing Fork and Blow Pipe.

The mixing fork and blow pipe can be madein any plumbing shop and should be made of thesmallest size pipe available.

61

Fig. 18.—Blow Pipe and Tip.

To make the mixing fork, purchase two ⅛-inchfemale hose end gas cocks and 2 feet of ⅛-inchiron pipe size brass tubing. Take a pieceof the tubing 12 inches long, cut a regular ironpipe thread on each end, then bend it over a mandrelstake or a piece of 4-inch soil pipe into a halfcircle, as shown in Fig. 15, so that the ends willcome about 4 inches apart. In the center of thispiece drill a ⅛-inch hole,a. Then cut from theremaining piece of tubing a piece 3 inches long.Solder, or, better yet, have this piece brazed onto the bent piece ata, taking care that no soldercan run in and partially stop the holea. Thenscrew the two ⅛-inch gas cocks on the endsb andc. This will complete the mixing fork; or thisfork can be made by bending a piece of pipe atan angle, as shown in Fig. 16; then cut anotherpiece equal in length to the bent piece from theanglee to the end. One end of this piece mustbe filed to fit the pieced. A hole can then bedrilled ate. Threads must be cut on these ends,after which they can be brazed together. Or a62good fork can be had by using a special casting.This casting is used for and is known as a beerswitch, and can be purchased of any dealer inbar supplies, Fig. 17. The same pattern and sizeof cocks can be used for this fork as previouslydescribed. Neither of these mixing forks hasany advantage over the other, but three stylesare given, as possibly one may be easier to makethan the other. Iron pipe may be used instead ofbrass if desired.

To make the blow pipe, take the remainingpiece of tubing and cut a thread on one end. Asthe other end slips into the hose, it does not needa thread. The thread end must then be bent atright angles to the tubing, asc, Fig. 16. Thiscan be done by boring a hole in a block of hardwood just large enough for the tubing to enter,and 1½ inches deep. Trim off the sharp edgeof this hole so as not to kink the pipe in bending.The end of the tube can then be inserted in thishole and bent to the desired shape, as shown.This completes the blow pipes with the exceptionof the tips, of which you should have three sizes,drilled as follows: One for heavy lead, 3-32; onefor medium weight, 2-32, and one for very lightsheets, 1-32. These tips are made of small piecesof cast or turned brass, preferably with a milled63shoulder, so as to facilitate removing with thefingers. Probably the easiest way to get thesetips is to make a pattern out of wood and haveseveral of them cast. They can then be drilledand tapped to any desired size, or they can becut from a round bar of brass or copper, filed orturned to a point, then drilled and tapped. Thedimensions and particulars can be had from B inFig. 18 without further description being necessary.A common blow pipe, such as is used withthe alcohol torch, can be used for practicing onlight sheets. But the beginner is advised to procurethe blow pipe and a set of tips described inFig. 18 before attempting to burn any heavylead.

After making sure that the generator is perfectlytight we will proceed to charge it. Afterremoving the 4-inch charging screw take 15pounds of commercial spelter, which has beenbroken up with a hammer into pieces about 2inches square, and place this in the gas chamber,distributing it as evenly as possible over the perforatedbottom. This is done so that the zincwill expose all the surface possible to the actionof the acid, and must be observed in order to obtainthe best results. Do not put any pieces ofspelter into the generator that are small enoughto drop through the perforated bottom, for ifthey do they will be likely to generate gas, whichwill give overpressure and blow gas out throughthe acid chamber. This can do no harm unlessclose to a light, but it is very annoying to haveacid blown all over the generator. The chargingand cleaning screws must be screwed uptight. After closing the gas cock on the generatortake the quantity of water (less one-seventh)65that was found to be necessary whentesting the apparatus, and pour this into the acidchamber.

Mark the water line and watch it for a fewmoments to make sure that everything is tight.Then take of sulphuric acid a quantity equal toone-seventh of the water used, and pour that intothe water in the acid chamber. It will diffuseitself through the water and thoroughly mix.Experience has taught me that acid mixed in anyproportion stronger than seven parts of water toone part of acid does not act as quickly as whenmixed in the proportion mentioned. The reasonfor this is that the strong acid simply coats thezinc with a deposit or scum of sulphate of zinc,which is soluble in water, but is not soluble inacid. Therefore, if the acid is diluted with waterto the above mentioned proportion the waterreadily dissolves the sulphate and allows the acidto act freely on the zinc.

This sulphate falls to the bottom of the gaschamber and if allowed to accumulate causes theclogging mentioned later. The beginner will observefrom the explanation that the generatorcannot be crowded by making the solution strong.It sometimes occurs that the vitriol seems to bestronger than usual, and then again the reverse66is also true. Good vitriol should be almost asthick as cutting oil, and will work very quickly.Care must be taken in pouring it into the generatorto prevent spattering. This is best avoidedby having a quart measure made of lead for thispurpose. It should also be borne in mind thattheacid should always be added to the water,never the water to the acid, as this mixture alwaysgenerates heat, and the result would besimilar to adding water to hot lead.

Automatic Action of the Generator.

The generator works best while hot. Thegas cock on the generator should now be openedand the mixture allowed to flow into the gaschamber until it spurts out of the gas cock, whichmust then be closed. By this action all the airin the gas chamber is expelled, leaving it free togenerate pure gas at once. This is a sure methodof exhausting the air in the gas chamber. Theacid then attacks the zinc, causing it to decomposethe water and free the hydrogen containedin the acid.

This gas, by reason of its lightness, will riseto the surface of the acid, and as pressure increasesit will force the acid back up through theacid supply pipe into the acid chamber, until the67acid falls below the perforated bottom. Whenthe acid and zinc cease to come in contact witheach other the generation of gas stops until gasis used, which relieves the pressure; then moreacid descends, and as it comes in contact withthe zinc more gas is generated, replacing thatwhich has been used. This action makes thegenerator automatic, unless clogging with sulphateof zinc takes place. This may happen atany time if the apparatus is not cleaned after eachday's use.

Cleaning the Generator.

To clean the generator in this case attach theair pump to the gas cock on the generator andforce the acid up into the acid chamber by pumpingair slowly into the gas chamber until the acidrises to the proper hight in the acid chamber,where it can be held by forcing a long woodenplug into the acid supply pipe. The pumpingmust cease when the acid rises to the proper level,or the excess pressure of air will work up throughthe supply pipe and cause a blow of acid.

The charging screw can then be removed andthe zinc taken out and washed in hot water. Removethe clean out screw and run one or twopails of hot water through the gas chamber. Thiswill remove the deposits of sulphate paste. The68zinc can then be replaced, the screws tightenedand the acid released again. Be sure and exhaustthe air in the gas chamber, as previouslydescribed, by letting the air spurt out of the gascock before connecting it to the scrubbing cup.Care must be taken not to have any lights nearthe generator when blowing out this mixture ofgas and air, as it is very explosive.

The apparatus will never clog if cleaned aftereach day's work, which should always be done.The tubes should be removed and hung up overnight to dry. The acid, if not spent, can bedipped out of the acid chamber and placed injugs. The generator can then be carried to adrain and filled with hot water, which should beallowed to flow out through the cleaning screw.This will clean the zinc and wash out all thesulphate deposit. The screws may then be tightenedand the apparatus left ready for the nextday's use.

Fire Trap and Scrubbing Cup.

One of the most essential parts of a lead burningapparatus is a reliable fire trap and scrubbingcup. This trap reduces to a minimum thedanger from explosion caused by neglecting tofree the gas from air. Its use as a scrubbing cupis also of infinite value.

69The action of the vitriol on the zinc producesa violent ebullition, and a small quantity of theacid is carried in the form of spray from the generatorto the tubes, and, unless caught and removed,will frequently get into the blow pipe tipand extinguish the flame, making it necessary toremove the hose and hang it up to drain and dry,which oftentimes causes waste of time and annoyance.

Almost all spelter or zinc contains more orless arsenic in a metallic state. It is also foundin sulphuric acid. This arsenic is released fromthe acid or zinc as they decompose and is carriedby the force of the volume of gas to the blowpipe tip, where, owing to it being necessary forthe operator to get his eyes close to the flames inorder to see the reducing flame, this poisonousgas will be breathed into the lungs and oftentimescause a fatal illness. This fact has been disputedby many, who say that it is impossible for theunit of lightness—i. e., hydrogen gas—to pickup and carry a heavy metal such as arsenic.Arsenic does not form a chemical combinationwith hydrogen, having a very slight affinity forit, but is carried to the blow pipe solely by theforce of the volume of gas.

To prove the above assertion we will refer70to Professor Marsh, who demonstrated the abilityof hydrogen to carry arsenic in the followingmanner: If a solution containing arsenic beadded to a solution of sulphuric acid and zinc,the resulting hydrogen will, upon ignition, deposita ring of metallic arsenic upon any cold surfacethat the flame be directed upon. (ProfessorMarsh's experiment.)

It will be seen from the above that it is imperativethat the operator use a scrubbing cupand see that it is properly filled with a solutionof blue vitriol. The ordinary impurities of hydrogengenerated in this manner are sulphur andcarbon, which should be removed if possible.

The actual use of the scrubbing cup is tocatch the above mentioned spray and precipitateto some extent all other impurities contained inthe gas, and produce gas sufficiently pure for leadburning.

Directions for Making the Cup.

To make this cup take a piece of 4-inch leadpipe 7 inches long (an ordinary piece of 4-inchlead soil pipe will do); flange out one end andburn in a flat bottom. Three inches from thebottom, and in the side of this 4-inch pipe, burnin a trap screw,a, Fig. 19, a screw taken froman old lead trap being just the thing. This is71to regulate the hight of the solution in the cup.Now make a top by taking a piece of lead andraising it about ¾ inch; punch two holes in thistop,b andc, large enough to let a ⅜-inch leadpipe pass through; flange out the top of the cupand fit and burn this top in place. Take two piecesof ⅜-inch lead pipe, one to be 3 inches long andthe other to be 10 inches long, and with thedresser draw one end of each to nearly a point,so that the hose can be slipped on tight. Thelong piecec should now be slipped through oneof the holes in the top of the cup, holding it ½inch from the bottomd and burning it in. Thisis the gas inlet and should be marked as such.The short piece is then placed in the remaininghole and burnt in place. The action will be thus:The gas entering the gas inlet pipe is caused topass through a solution of blue vitriol 2½ inchesdeep, when the acid is caught and the gas isscrubbed and rendered as nearly pure as possible.It then enters the outlet pipe and is readyfor use. If the directions have been followed thecup will resemble the illustration Fig. 17. Notrouble will be experienced with this cup.

Fig. 19.—Fire Trap and Scrubbing Cup.

Before attempting to light the gas the operatormust be sure that all the air is exhaustedfrom the tubes. Otherwise the flame will go backand explode in the tubes or fire trap. To be sureof this the beginner must test the gas. A handytest tube can be made by capping one end of apiece of ½-inch pipe, which should be about 6inches long. To test the gas, first open wide thegas cock M on the generator, Fig. 1. Thenopen the gas cockf on the mixing fork and letthe gas displace the air in the tubes, which it willdo in about one minute. Then invert the testtube, Fig. 20, and hold it over the blow pipe tipfor a moment until the gas has displaced the airin the tube. Then quickly place your thumb overthe opening of the test tube, which will keep thegas from escaping. Close the gas cockf on themixing fork, then take the test tube to one sideaway from the generator, still keeping it inverted,and bring it close to a lighted match orcandle. It will light with a pop, and if it is free74from air it will burn quietly down in the tubeuntil the gas is exhausted. Continue to test thegas in this manner until it burns as described,when it may be safely lit at the jet without fearof its burning back. This precaution is necessaryonly after opening the generator for somepurpose.

Fig. 20.—Method of Testing Gas.

Regulating Volume and Pressure.

This generator evolves gas under a greaterpressure than can be used on most work, and forthis reason the flame will at first be long, noisyand unsteady, as shown in A, Fig. 21, but, asthere are two cocks, the volume and pressure canbe regulated to the requirements of the work at75hand. Now, to note the peculiarities of thisflame, we will close the gas cockf on the mixingfork until the flame is about 3 inches long. Itwill be of a pale reddish color and will burn steadily.The inner flame is not as yet very well defined.Then open the air cockg slowly, andwhen sufficient air has been admitted the flamewill be seen to shoot out suddenly and thenshorten to about 1¾ or 2 inches in length. Itwill be smooth, compact, and will have the appearanceof darting rapidly. If the correct quantityof air has been admitted the inner flame, asshown in B, Fig. 21, will then be plainly seen,and its apex, which is the point of greatest heat,will be blue. This inner flame is known as thenonoxidizing flame, and is the flame with whichthe fusing is done.

Fig. 21.—Flames Under Different Pressures.

76The outer flame will change to a bluish color.Its temperature is low, and its effect on the leadis to coat the metal with a heavy blue oxide, underwhich the lead runs but does not unite. To demonstratethis, bring the point of the inner or nonoxidizingflame to bear on a piece of sheet lead.It will fuse bright and clean and will have a circleof gray oxide around it. Then quickly removethe flame and the spot will remain bright.Now, again bring the flame to bear on the samepiece of lead, keeping the point of the inner flameat least ¾ inch away from the lead. It will meltand flow together, but will be covered with acoat of gray oxide and the union will not beperfect. Slowly withdraw the flame, and beforethe flame is entirely removed the spot will beheavily coated with a thick blue oxide, underwhich the lead will not unite. C, in Fig. 21,shows the appearance of the flame when toomuch air has been admitted and it is on the pointof going out from lack of gas.

The proper way to use the gas is to open wide77the gas cock M on the generator, and do anyregulating of the flame with the gas cockf onthe mixing fork. These cocks should have piecesof heavy wire brazed or soldered lengthwise ofthe handles, Fig. 16,h andi, so as to form leverhandles. This will allow the gas and air cocksto be closed or opened by gently tapping the leversh andi, which is the only way that a slightvariation can be had, for if you try to regulatethem with the finger you will constantly open orclose them too much, and the result is that in addingair too much is always admitted, which willblow out the flame, making it necessary to turnoff the air and light the jet again, and many timesthis operation will have to be repeated before theflame is correctly adjusted.

It must be remembered to always turn on andlight the gas before admitting any air, and whenthrough with the flame the air must be turned offfirst, then the gas. If this operation is reversedan explosive mixture of gas and air would formin the tube and would spoil the tube, if nothingworse.

Study the Flame Well.

The beginner should study the flame untilperfectly familiar with the color and form of theproper flame. One of the greatest troubles that78the beginner will have with the blow pipe is theinability to regulate the flame to the requirementsof the work. For instance: A flame thatwould work nicely on 12-pound sheets wouldburn holes in 4-pound sheets before you had timeto touch the lead with the inner flame. For thatreason three different sizes of tips should beused. On a 2-pound sheet the smallest, or 1-32,tip should be used, and the flame before reducingshould not be longer than ¾ inch, and whenreduced the inner flame can hardly be distinguished,but you can easily tell when it touchesthe lead by the metal fusing bright. If it is desiredto fuse 12-pound sheets the 2-32-inch tipshould be substituted, and it would be found necessaryto have the jet of gas about 3 inches long,which, when reduced, would be about 2 incheslong and would show the inner flame very distinctly.

The only way to determine the size of theflame necessary is by experimenting with it. Itwill also come with experience. The flame shouldbe reduced to a size that will not melt the leadas soon as it touches it. Rather, it should be insuch condition that the lead would have to beheated first and let the fusing come gradually.In that way it can be determined just what sized79drop is required, and also plenty of time is allowedto place it just where it is wanted—particularlyon upright seams andimperatively oninverted seams.

It is not necessary to be so particular on horizontalseams, as on seams in that position you areassisted by gravity. The lead drop that is meltedfrom the upper lap cannot do otherwise thanunite with the under lap. It must be rememberedthat in starting a seam you have cold leadto fuse, and after the first drop is started the leadin its vicinity will be heated almost to the meltingpoint, and you will probably be surprised to seethe lead run at the approach of the flame for thenext application.

Do Not Hurry.

The point to be taught here is that you mustnot attempt to hurry this work or holes willsurely be burned in the sheets, which oftentimesmakes difficult work to patch. The old adage,“haste makes waste,” can well be applied to leadburning. Sufficient time must be allowed for onedrop to set before attempting to place the nextdrop. Time spent on practicing at the bench istime well spent, as many little details that cannotbe brought to the beginner's attention herewill be learned in that way and stored in his mindfor future application.

There are two kinds of seams proper, viz.:The butt seam and the lap seam. The butt seamis used principally for joining horizontal wastepipes and in lengthening traps, or for any purposewhere it is desired not to have the point ofjunction show. This form of seam can be burnedclear through—that is, the lead can be heateduntil fusion takes place nearly through the entiresheet. It is generally necessary to add lead tothe seam if it is desired to make the seam asstrong as the sheet it joins, unless the article tobe burned is of such a size as to be possible toallow of its being burned on both sides, whichmakes the strongest of seams. The lead for thebutt seams is prepared by rasping the edges ofthe lead sheet to be joined straight and true, Fig.22, so that when the edges of the lead are broughttogether they will fit close its entire length. Theedges are then shaved for a distance of ⅛inch each side of the edge, making a seam ¼inch wide. On stock heavier than 12-pound81sheets the edge should be shaved off, making adeep V-shaped groove, and the seams must bemade by adding lead. This allows the fusion totake place nearly through the sheet. The buttseam is the simplest form to burn, no matter inwhat position it is placed.

Fig. 22.—Rasping the Edges of the Lead Sheet Straight and True.

The lap seam is the seam commonly used, andas between the butt seam and the lap seam thelatter is generally to be preferred. As it is notnecessary to cut and trim the edges true, it dispenseswith any additions of lead, except at rareintervals; it leaves the left hand free to handlethe shave hook, and the lap can be dressed to fitany uneven spots. It also makes the next bestseam to through fusing. By lap seaming a tankcan be lined in about half the time required to82butt seam the same article, which is an importantitem to the customer.

Fig. 23.—Burning a Lap Seam.

The lead for this form of seam is prepared,as its name indicates, by lapping one sheet½ to ¾ inch over the other sheet. The underedges are to be shaved clean, as also the upperedge. The lead required to make the seam ismelted from the upper lap and is fused on thelower sheet. There is no reason why the lead atthe point of juncture cannot be made as thick asthe original lead. This is the point aimed at inpracticing, and the only accurate way to determinethe relative strength of the seams is to cutsquarely across a finished seam, then bend thebeam slightly. The thickness can then be noted.A cross section of a perfect lap seam is shown83ata in Fig. 23. The beginner should practice thedifferent seams until the thickness of the jointcan be told by the looks of the lead. A few days'diligent practice at the bench will soon train theeye to note any imperfection that may arise.

The different seams will be taken up serially.A description of how the seams are prepared andthe several positions of the blow pipe, as well asthe little difficulties that may arise, is the extentof the instruction that can be given. The restmust come with practice and the application of alittle common sense. There is no royal road tothis business; but practice, and practice hard, isthe only way to satisfactorily master the blowpipe and flame, and in practicing remember thatall this work has been done before, and can beeasily done again,and by you. Do not get discouragedby failure to make a perfect seam atthe first application, but stick to it for a shorttime and it will be found to be a most fascinatingpastime, for which the persistent student willeventually be well repaid.

Flat Butt Seam.

For practicing I would recommend the beginnerto use pieces of sheet lead about 12 incheslong, as strips of that length are much easier to84prepare. The edges are straightened with a finerasp which is held lengthwise of and parallel tothe edge to be trued, in the manner shown in Fig.22. The rasp must be used lightly, or it will beapt to tear the lead and so leave it in worse conditionthan before using it. The edge should thenbe gone over with the shave hook and cleaned.Then shave the top surface a distance of ⅛ incheach way from the edge, which will make a seam¼ inch wide when finished. Then butt the edgestogether and secure the sheets firmly to a boardwith a few tacks. The extra lead that is necessaryto add to make a butt joint full must be obtainedfrom a strip of lead, which should beabout ⅛ inch square andshaved clean.

After regulating the flame to the proper sizeand shape the burning should be begun at theend of the seam nearest the operator. With thepoint of the inner flame melt off a drop from thelead strip and have it fall squarely on the seamjust slightly in advance of the point of fusion.Follow it up with the flame, placing the point ofthe inner flame directly over the edges of theseam, which is almost under the lead drop. Assoon as fusion commences on the lead seam themelted drop will flow to the bright spot and immediatelyunite with it. The flame must then85be quickly removed and the drop be allowed toset.

In order to avoid any misunderstanding regardingthe time required for the lead drop toset I would say that the drop will cool immediatelyupon the flame being removed from contactwith it. It is not necessary to wait for anyspecified time, but if the flame is allowed to playconstantly on the sheet it is apt to get overheated,and when in that condition it takes very littleheat to set the lead running like water. To avoidthis the flame should be lifted clear of the seamfor an instant after each drop has been fusedinto place.

Fig. 24.—Burning a Flat Butt Seam.

These remarks apply to all seams that aremade by the blow pipe process and should be86noted, as this particular point will not be referredto again. Now melt off another drop and let itfall as before, only it should lap on the previousdrop about one-half its diameter. Secure it tothe seam as before. This operation should be repeateduntil the seam is completed, and if theseam is correctly done a section will appear asain Fig. 24. This form of flat seam should bepracticed until perfectly familiar with the blowpipe flame and until the beginner can approachthe lead with the flame without burning holesthrough it, which will probably be the first thingto happen.

Upright Butt Seam.

The upright butt seam is seldom used on largework, as it is a difficult matter to make an uprightbutt seam that will stand the test, as, if a finishedseam is cut into short pieces, an examination ofthe severed ends will show many weak places thatwere previously thought to be very strong. Thereason of this is that the heat necessary to fusethrough the lead will cause the lead to run fromthe seam and leave a hole.

The sheets for practice are prepared as describedfor flat butt seams, and must be securelytacked to a board which can be supported in anupright position. The burning is begun at the87bottom of the seam. The flame must be shortenedconsiderably, as the fusing must take placesomewhat slower than in flat seams, as in uprightor inverted seams the attraction of gravityremains to be overcome, and the operator musthave plenty of time between the commencementof brightening and the actual fusing to drive themelting drop to the exact position desired.

Fig. 25.—Burning an Upright Butt Seam.

The blow pipe is held so that the flame strikesthe seam squarely and at about a right angle withthe sheet, as shown in Fig. 25. When fusionstarts the flame should be drawn quickly to one88side, and if the lead is at the proper temperaturethe melted drop will follow the point of flame,and as it comes in contact with the adjoining edgeit will properly unite. It is not necessary to addlead to these seams oftener than at intervals of5 or 6 inches, or as often as the lead shows signsof weakening, when it may be added by holdingthe lead strip against the lead sheet and slightlyabove the flame. The melted drop will unite withthe sheet and can then be driven to any desiredposition. This seam will show the characteristicbeads, but they will lie nearly level with the leadsheets, and if a scratch cloth be rubbed over theseam all traces of the position of the seam willbe removed.

To make a really strong seam it must be goneover with the flame at least twice, as after fusionof the edges takes place the flame can be usedquite strong without fear of the lead runningfrom the seam. Do not leave this seam until youare satisfied that it is nearly perfect. It is goodpractice, and every hour spent only makes themastery of the next seam come so much morequickly.

Horizontal Butt Seam.

This form of seam cannot be used to any advantageon general work, but, like seams in other89positions, it cannot always be avoided. The practicesheets are prepared and tacked securely tothe board, as previously described, and are thenplaced in the position shown in Fig. 26. Theposition of the blow pipe is as shown ata. Theflame should strike the sheet nearly square. Theedge of the upper sheet should be heated first, andas it brightens the flame should be directed ontothe edge of the lower sheet. If properly done,fusion will at once take place.

Fig. 26.—Burning a Horizontal Butt Seam.

The object sought is to get a light fusion betweenthe two sheets before attempting to burnthe lead clear through the seam. If this is notdone, the lead will run from the upper sheet andcause holes, or at least will seriously weaken90the upper sheet, as shown in cross section atb.After fusion is once obtained it is a simple matterto go over the seam a second time, which canthen be fused clear through without much dangerof burning holes through the sheet. Leadcan be added in the same manner as in uprightseams if necessary.

Inverted Butt Seam.

This seam is used extensively in joining wastepipes which conduct the acid from tanks to thedrain. These pipes are usually in a horizontalposition and the seams must be burned in place.The most difficult part of the seam is in startingit. When fusion has once taken place the balanceof the seam is easy. The seam is preparedthe same as described for other butt seams. Caremust be taken to have the edges butt close. Theboard can then be supported in the required positionby any convenient device.

The blow pipe flame must be made as shortas possible and still melt the lead. The point ofthe inner flame is then placed squarely on theseam. Both edges must be heated at once. Ifthe edges begin to brighten and do not show aninclination to fuse, the flame should be drawnquickly to one side, and the melted drop will follow91the point of flame and unite with the adjoiningedge. This seam, in common with the otherbutt seams, should be gone over the second timeto assure a perfect seam. It is difficult work toadd lead to the flat inverted seam. When necessaryto do so, however, it can be added by burningthe end of the lead strip to the seam. Thestrip is then melted off, leaving a drop of leadaffixed to the seam, which can then be drawn tothe required spot with the flame.

The characteristic inverted seam shows pitsupon examination of the reverse side of thesheets. These are caused by overheating. Theoperator will often be surprised at the invertedbutt seam showing a remarkable fullness. Thisis accounted for upon the examination above referredto. The lead, upon the application of theheat, runs from the upper or back side of thesheet and forms a very full seam. For that reasonthe inverted butt seams always appearstronger than they really are. See inverted lapseam, Fig. 27.

Lap Seams.

The lap seams are the seams commonly used onall classes of work. When the beginner becomesproficient with the blow pipe no trouble will beexperienced in making lap seams that will show92when cut a joint equal in thickness to the sheetsthat are joined. The lead sheets for the flat lapseam are prepared by shaving clean the exposededge; also, shave the sheets where they toucheach other. The upper edges can then be shavedfor a distance of ⅛ inch each side of the lap,which will make the finished seam ¾ inch wide,as shown ata in Fig. 23. The sheets should belapped ½ to ¾ inch, according to the weight ofthe stock. It is very evident that light weightswould not require as large a lap as would heaviersheets, as the object of lapping the sheets isto leave the sheets practically as one piece, andthe lead, to accomplish this object, is to be meltedfrom the upper sheet.

Fig. 27.—Burning an Inverted Lap Seam.

93From the foregoing it will be seen why a 12-poundsheet requires a ½-inch lap, while a 24-poundsheet would require a ¾-inch lap. Theflame, when regulated to the work, is brought tobear squarely on the edge of the upper sheet,slanting slightly in the direction of the lowersheet, as shown. When the edge has brightenedalmost to the fusing point the blow pipe shouldbe drawn quickly to one side and from the uppersheet to the lower sheet. If the metal is sufficientlyhot the melted drop will follow the pointof the flame and instantly fuse with the lowersheet, and if properly done the seam will resembleb in Fig. 23. This process is repeated,advancing about ⅛ to ¼ inch each time. Donot attempt to fuse a large surface at a time.Experts cannot do such a thing satisfactorily, sowhy should a beginner try to? Rather, try tofuse small surfaces quickly and strongly, as betterwork and more of it can be accomplished inthat manner.

Horizontal Lap Seams.

This seam is prepared precisely as describedfor flat lap seams. The strips can be fastened toa board with a few tacks. The strips can then94be supported in the position shown in Fig. 28.The burning is commenced, as before, at the sidenearest the operator. The flame must be madeas short as is consistent with the weight of thestock. It will be found to the beginner's advantageto have fusion take place slowly. The pointof the inner flame is brought to bear on the outeredge of the lapped sheet and at an angle of 45degrees. Both sheets should begin to brightenat about the same time. The melted drop mustbe driven against the back sheet by the force ofthe jet of flame, and if the sheets are clean fusionwill take place quickly.

Fig. 28.—Burning a Horizontal Lap Seam.

The drops or beads of lead will appear very95small on this form of seam, owing to that greatobstacle, gravity, which causes the drop whenmelted to flow downward and so swell the seam.The drops, in common with other forms of lapseams, should be made short, letting each dropoverlap the previous drop as much as possible.Great care must be taken not to weaken the seam,as shown ata. The beginner should strive toget the seams so that when cut into small sectionseach section will resemble the result shown atb.

Upright Lap Seams.

Prepare the sheets as for flat lap seams, fasteningthe sheets securely to a board, as previouslydescribed. The burning should be begunat the lowest point of the seam. After regulatingthe flame, the point of the inner flame is appliedto the edge of the outer sheet slightly abovethe point decided upon as the starting point, andat an angle of about 30 degrees, as shown atain Fig. 29. As the drop begins to melt it willhave a tendency to flow downward. By a quickturn of the wrist the flame must then be directedagainst the back sheet and slightly under themelting drop.

The under sheet should brighten at once, andthe force of the flame, being partially directed96against the melted drop, tends to force it againstthe bright spot on the back sheet, with which itinstantly unites. The flame must then be withdrawnfor an instant, to give the fused drop timeto set. The operation must be repeated until theseam is finished. Using ordinary language, itmay be said that the drop is cut from the uppersheet, carried slightly downward and then stuckagainst the back sheet by the force of the flame.

Fig. 29.—Burning an Upright Lap Seam.

This seam is the one most used, and the beginnershould practice it diligently. After masteringit in the position shown in the cut, theboard should be fastened to the floor and the beginner97should practice burning the upright seamfrom above the work. This position occurs manytimes in lining tanks, and the beginner who conquersthe upright seam in that position can considerhimself sufficiently proficient to attend toany job of lead burning that may arise. Thebeads of lead will appear more compact and regularthan in the flat seam, and if properly done willupon cutting the sample show a very strong joint.

Inverted Lap Seam.

This seam should be attempted only after becomingvery proficient with the blow pipe andflame, after which it becomes as easy to burn asin any other position. In order to get the rangeof the seam the sheets should be arranged in theposition shown in Fig. 27. The burning is begunon the upright seam, and continued up andover the curved portion and on to the invertedseam. The graduation from the upright seam tothe inverted seam is simple and gradual, and ishardly noticeable.

After accomplishing the inverted seam in thismanner, strips of lead should be prepared andfastened to the board as described for uprightseams. The board should be supported in an invertedposition at a convenient hight over the98operator's head. The flame should be shortenedas much as possible. The burning may be startedat any convenient point and continue in eachdirection. The point of the inner flame is appliedto the seam at a slight angle, asa. The object isto obtain a fusion between the back sheet and theupper edge of the lap. When this is accomplishedfusion proceeds easily.

Fig. 30.—Burning an Inverted Corner Seam.

The hardest part of this seam is in startingit, and when once started, with a little patienceand care, the balance of the seam can be fusedwithout any trouble. Fig. 30 shows an exercisewhich the beginner should practice after having99conquered Fig. 27, as it teaches the making ofan inverted corner seam. Of course, this positionseldom occurs in small work, but if the burningof it is once accomplished it will give theoperator considerable confidence in his own ability.

The Butt Seam on Round Pipe.

Pipes that are placed in a horizontal positionare usually butt seamed, as a stronger seam canbe made in that manner. This form of seam isalso used in lengthening traps, bends, etc. Toprepare a round pipe for butt seaming, the endsof the pipe should first be made perfectly roundby inserting a drift plug and dressing the lead upclose to it. The ends of the pipe should be raspedtrue and then shaved clean. Also shave the pipefor a distance of ⅛ inch each side of the edge.A piece of stiff writing paper should then berolled up the size of the pipe and inserted in theends. This paper will prevent any lead fromrunning into the pipe and leaving rough edges,as these afterward form an obstruction.

The burning should be commenced at the underside of the pipe, Fig. 31, and proceed bothways from the starting point and finish at thetop. If the beginner has successfully overcomethe difficulties of the seams preceding this he will101find no trouble in making a strong and workmanlikeseam on this pipe. Pipes are seldom usedheavier than the grade known as D for this classof work, and for that reason it is seldom necessaryto add lead to these seams. But if a holeshould be burned in the pipe on the under side,lead should be added to the top side of the pipeand then made to follow the flame to the desiredspot. This will be found a quicker and more certainmethod than attempting to add lead directlyto the hole. A properly burned pipe should showthe full thickness of the pipe when cut with a saw.

Fig. 31.—Burning a Butt Seam on Round Pipe.

Through Seam on Round Pipe.

Where heavy pipe that is to be used underpressure is to be joined it must be burned through102to provide strength, and the ends prepared in thesame way as just described, but the ends mustalso be trimmed off all the way around with aslight bevel reaching from the outside almost tothe inside bore of the pipe. The bevel must stopso as to allow a narrow square butt end on eachpipe. Then when a piece of paper has beenplaced on the inside to prevent lead running intothe pipe, the two ends when butted will presenta V-shaped groove, as shown in Fig. 32, reachingall around the pipe. The burning is commencedat the bottom, as shown in Fig. 31, andthe two ends securely united. The groove is thenfilled by burning on additional lead from a thincleaned strip until the groove is filled and the pipemade as heavy and strong at this point as anywhereon its entire length.

Fig. 32.—Joint Prepared for Through Burning.

Fig. 33.—Preparing for a Lap Seam.

Fig. 34.—Burning a Lap Seam on Round Pipe.

This seam is used almost exclusively on pipein a vertical position, and is similar to the horizontallap seam. The pipe is prepared by spreadingthe lower piece of pipe with a drift plug onesize larger than the size of the pipe used. Theend of the pipe intended to enter this socket israsped to a bevel edge, as shown ata, Fig. 33.This end is then shaved clean, as is also the insideof the socket. The pipe is then placed intothe socket, which is then dressed up tight againstthe inserted pipe, as shown in Fig. 34. The exposed104edge is then cleaned and burned, as describedfor horizontal lap seams.

The Tee Joint on Round Pipe.

Fig. 35.—Making a Tee Joint on Round Pipe.

With a pair of compasses set the diameter ofthe pipe that it is desired to insert, and strike acircle on the pipe which is to receive the tee.With a tap borer, or any other device, cut out acircle of lead, leaving about ¼ inch to turn up.Then draw this remaining lead up by means of abending iron and a heavy piece of iron, such as105a chisel, as shown at B in Fig. 35, until the holeis large enough to receive the piece intended forit, the end of which should be beveled with a finerasp, as shown ata. The lead should then bedressed back against the pipe, after which removethe piece and shave clean, and proceed toburn as described for the lap seam on round pipe,and as shown in Fig. 36. Care must be taken indressing up the lead flange to dress it slowly soas to avoid weakening the lead.

Lining Tanks.

The lining of chemical tanks being the principalwork of the chemical plumber, a descriptionof how this work is done will probably be ofsome use to the beginner. In preparing leadsheets for a tank the sheets should be cut so asto give the most seams on the bottom, becauseof the greater ease in making them. In largetanks I find it convenient to put the bottom infirst, cutting it to make an easy fit, and then thesides are put in. These are cut to allow ¾-inchlap on the bottom.

The lead sheets are laid on the floor, or someother smooth place, which has previously beenswept clean, and then dressed out smooth. Thiscan best be done by using the wooden dresser to106take out the large wrinkles and then smoothingwith a lead flap. This flap is simply a piece ofsheet lead about 3 inches wide and 12 incheslong, one end of which is drawn into a roll to fitthe hand. Then mark the laps and bend them tothe desired position. The under side of the lapshould be shaved clean, as also the lead under thelap, to facilitate fusion.

Fig. 36.—Burning in the Tee Joint.

If the tank is over 18 inches high the leadmust be fastened to the sides with bullseyes.These are made by countersinking places in thesides of the tank. The lead is then dressed intothese holes and it is held in place with largeheaded brass screws, which are covered by burningover the heads. Lead for the purpose is takenfrom lead strips. The building up process is resortedto in covering these screw heads.

107The lead should be arranged so as to avoidcorner seams as much as possible, as it is quite adifficult job to get the proper thickness of leadin such seams. No rule can be given for cuttinglead to fit a tank, as tanks are of such a varietyof sizes and shapes, and the lead is of so manywidths, that the mechanic must study how to cutthe stock without waste and have as few seamsas possible.

It is not my intention to give an elaboratedescription of how acids are made or to attemptto describe all of the different fittings employedin that work, because while all plants are similarin construction no two are alike. For that reasonI will confine myself to the methods employedin handling lead in large quantities, as the leadused in this work ranges in weight from 18 to 24pounds to the foot and is therefore very heavy tohandle. These chambers are known as condensingchambers, and their use is to catch and condensea mixture of sulphur and steam which isblown into them through a large lead pipe. Forthat reason they are usually built out of doors,and sometimes have a sort of temporary roofbuilt over them. Consequently in repairing theyare easily gotten at, which, by the way, is seldomnecessary.

109

Fig. 37.—Method of Framing Chamber.

To begin with, the sheet lead should be purchasedof such a width as to make as few seamsas possible. The bottom of the chamber for thislead to lie upon should be made of 2-inch cypressplank, the same to be tongued and grooved asfor floors, and should be planed down, if necessary,so that it will present a perfectly smoothsurface for the lead to rest upon, for if there areany uneven spots that is where the lead willeventually crack. The frame work for the sidesshould also be put in place before the lead workis started, or at least enough of it to prevent dirtand other stuff from bothering the burner. Oneend of the chamber, however, should be left open,so as to enable the workmen to bring in the leador other material. The sides should not be closedup, but should be framed, as shown in Fig. 37, soas to allow the lead to be securely fastened to theframe work, which should be made of heavystock, depending, of course, upon the depth and110size of chamber, as they are in all sizes, from 10feet to 60 feet long and longer.

After seeing that this part of the work is allright, begin to place the bottom in position. Thislead should be cut large enough to allow of itsbeing turned up about 2 inches all around fortight tanks. The sides are not burned to the bottomsof some chambers, but the bottom lead isturned up different hights, depending upon howdeep it is required to carry the acid in the chamber,which is from 4 to 10 inches or deeper. Thestudding should be notched out to allow theturned up lead to face with the face of the studding,otherwise there would be a bend in the sidelead where it overlaps the sides of the bottom.The flat seams in the bottom should be buttedtogether, so as to give a perfectly smooth surface,which will allow all the acid to be drawn off.

Fig. 38.—Chipping Knife.

111

Fig. 39.—(A) Strap Split and Bent in Alternate Directions. (B) Bevel End of Strap.

It is rather a difficult task for some men tocut heavy lead straight. This is easily accomplishedby first marking a chalk line on the leadwhere it is desired to cut it off; then, taking thehammer and chipping knife, as shown in Fig. 38,dip the blade of the knife in water, lay the bladesquare on the line and strike the back of the bladelightly with the hammer. Mark the sheet thewhole length in this manner. Then go over itagain and repeat the operation, making sure thatthe knife is held straight. The blade of the knifemust be kept wet or it will stick in the lead andcause it to glance off sideways. After it is cutany uneven spots can be planed off smooth witha small smoothing plane, set so as to take off avery light chip. The lead should now be placedin position and dressed smoothly by using a pieceof pine, or other soft board, as a dresser. Thismust be laid on any uneven spots and thenpounded down smooth with a heavy wooden mallet,after which the seams should be shaved andburned at once; or if the seams are short and it isdesired to put in enough work one day to keepthe burner busy the next, strips of paper 6 inches112wide should be pasted over the seams to keep thedust out. Only the edges of the paper shouldbe pasted, so that when ready to burn all that willbe necessary is to take hold of one end of thepaper and strip it off, leaving the seam clean andfree from dust and paste and ready to shave andburn.

Fig. 40.—Roll of Lead in Position.

After the bottom is finished the sides must beput in, in such a manner as to have as few seamsin an upright position as possible, as it saves considerabletime to burn them when horizontal. Onsmall chambers or tanks not over 10 feet deepthe carpenter should make a staging wide enoughto receive two sheets of lead and as long as thetank is deep. The bottom of the chamber shouldthen be covered with boards, so as to preventdamage to the lead. The staging is then brought113in and set up on horses, and the sheets of lead arecut off and laid on the staging. The seams arelapped, shaved and burned, after which the leadtacks or straps are cut and burned on, to supportthe lead when in position.

There are different ways of putting on thesestraps. For side lead I use strips of the lead itselfabout 3 inches wide and long enough to lapwell onto the studding. My way is to split thisstrip about ½ inch deep and bend the ends inalternate directions. The edges are then cut off,as shown at A, Fig. 39, after which they areburned in place. These straps should be spacednot more than 15 inches apart, and should beplaced in such a manner as to come on the upperside of the studding.

Fig. 41.—Clamp and Method of Applying.

Another method of putting on these tacks,and one which is most commonly practiced, is totrim the end of the strip of lead as shown at B,114Fig. 39. The strip is laid flat on the lead sheet,with the bevel end down, and is then burned ontothe sheet in that position, after which it is bentover the studding and nailed. The exponents ofthis method claim that a better job is done in thatmanner, as there is always a lifting pull on thestrap. I claim for the first method that there ismore strength in the lead seam, and that as theedge of the studding comes directly under thestrap it acts as a sort of shelf for the strap andthereby becomes a strong brace. But it is probablyonly a matter of habit, as they hold all righteither way.

Now, after having the seams burned and thestraps in place, the lead must be put in position.This can be accomplished by any arrangementof block and tackles, but if the chamber be verylarge it will be found to be a saving of time andlabor to rig up a derrick. This is not such an expensivething to do, as a carpenter is always onhand and most likely all the material needed isalready on the ground. This derrick should beconstructed with a swinging boom, so that it canbe raised, lowered or swung into any desiredposition.

115

Fig. 42.—Showing Staging in Position.

Now to raise the side lead into position: Thederrick is hooked onto the hook or rope that ison the upper end of the staging. It can then beeasily raised in position. If the tank be verydeep, or if it should be too narrow to follow thismethod, the sheet lead should be rolled up on apiece of 2, 3 or 4 inch iron pipe, depending uponthe weight of the lead. This pipe should be longenough to project at least 6 inches from both endsof the roll. Two timbers, long enough to crossthe frame work, should be obtained. About 18inches from one end of each timber a notchshould be cut to prevent the pipe from rolling.These timbers must now be placed across theframe work just over the place that is intendedfor the lead. The whole roll can now be raised116with the derrick and the ends of the pipe placedin the notches. The lead can then be pulleddown, similar to pulling down a window shade,after which the tacks can be burned on in place.This is shown ata, Fig. 40. Or if there be roomenough the piece of lead can be cut from the roll,dressed smooth and have the tacks burned onwhile on the floor. The upper end of the leadcan then be rolled over and nailed to a piece oftimber 2 × 6 inches or heavier, and the derrickhooked onto this and raised in position. This isthe easiest method where there is room to do it.These are a few of the methods used, but thereare numerous other ways.

To place the top lead in position requires astaging, which can be built as follows: Enoughhooks should be made to properly support thestaging, shown at A, Fig. 41. Two timbersshould be laid across the top of the chamber, farenough apart to allow two strips of lead to beplaced in position at once. The hooks are nowhooked over these timbers, while two pieces of3 × 3 or 4 × 4 are placed in the other end of thehook. Planks are now laid over these timbersand the screws set up until the tops of the plankscome just level with the top of the lead—nothigher, or else they will prevent the joist frombeing placed in position.

117The lead can now be cut off on the groundand hoisted up to the top, where it becomes aneasy matter to place it in position. The lead tackscan now also be cut and burned on. They shouldbe cut sufficiently long to allow them to lap overthe top of the joist, as shown ata, Fig. 42, wherethey should be nailed with large headed nails. Itwill be noticed that the tacks are doubled up onthe top lead and that they are not set oppositeeach other. The joist can now be set and thetacks nailed on, after which ropes can be tied ontothe projecting ends of the 4 × 4 timbers and thewhole staging be lowered to the floor at once.This operation can be repeated until the wholetop is on.

Fig. 43.—Lead Headed Nail.

It will be necessary to leave small holes betweenthe lead seams at intervals for the hooksto pass through. However, these can be burnedover at any time, and where the ends of the topshould overlap the end of the chamber the leadcan be left turned up until the staging is removed,after which it can be turned over and118burned. The hooks are made of ⅝ round ironand have a long thread cut on one end, so asto allow for adjustment. The details are shownin Fig. 41. There are also numerous fittingsused in connection with these condensing chambers,but they are all easily made and are toosimple to take up space here in explanation.Should it be necessary to use nails for any purposeon the inside of the chamber, the headsshould be dipped into a pot of melted lead thathas not quite set until the adhering ball of leadis about ½ inch in diameter, as shown in Fig. 43.These nails can be driven in place and the leadburned to the sheet lead, which will prevent corrosion.

The articles on the universal method of leadburning having been completed, I desire to callattention to a new method and a new generatorrecently patented and put on the market by theKirkwood & Herr Hydrogen Machine Company,3129 South State street, Chicago, Ill. It is calledthe Kirkwood generator and a general view of itis given in Fig. 44. This generator is a radicaldeparture from the old style generator, as usedfor the purpose of lead burning, inasmuch as itdispenses with the air blast and consequently withthe mixing fork and tubes. The air required toreduce the hydrogen gas to a working conditionis obtained by absorbing the air at the mouth ofthe burner.

The new generator differs also in the amountof pressure used on the gas. With the old stylegenerator, previously described, a pressure of1½ to 2 pounds is used, whereas the Kirkwoodgenerator is used under a pressure varying from8 to 30 pounds. At the higher pressure the maker120claims the best results are obtained. The generatoris made in a size that enables the operatorto take it to a job on a street car or train, andthat while containing the full charge of acid andzinc, as it weighs when charged about 50 pounds.This is a very important advantage over the oldstyle machine.

Construction of the Generator.

The generator is constructed, so to speak,just the reverse of the old style generator, inasmuchas the lower chamber contains the chargeof acid, while the zinc is placed in the upperchamber. The generator shown in the sectionalview, Fig. 45, is cylindrical in shape, 9 inchesin diameter and 30 inches high. A horizontalpartition, to which is burned a pipe long enoughto reach to a point about 1 inch above the bottomof the acid chamber, is burned into the cylinderat a point a little above the middle of thecylinder, making the acid chamber larger thanthe gas chamber. This arrangement allows theback pressure of gas to force the acid down intothe acid chamber, compressing the air in the acidchamber without permitting any gas to find itsway into the acid chamber and thus preventing awaste of gas. In this horizontal partition andover the pendent pipe a number of ¼-inch holes121are drilled or punched. This enables the acid topass freely into the gas chamber, and preventsany small particles of zinc from falling into theacid chamber, which would generate gas in thechamber. Connected to the top of this acid chamberis a small pipe which runs up through the gaschamber and terminates above it, as shown. Thispipe has an air inlet valve, or small hose end gascock, connected into the side of the pipe, to whichthe hose from the force pump is attached whensupplying air to the acid chamber to force fromthe acid chamber to the gas chamber in order tostart the generation of gas. A safety or blowoff valve is also attached to this pipe at the top,and is set to an ordinary working pressure of 15pounds, or to any pressure desired. If gas is beinggenerated faster than is required it gets up apressure in excess of 15 pounds. Then the safetyvalve opens and allows the air in the acid chamberto escape until the gas goes down to the desiredpressure again. This obviously allows aportion of the acid to return to the acid chamber,and later, as the acid becomes weaker, the air inthis chamber will have to be renewed by the admissionof a little more air.

Fig. 44.—General View.	Fig. 45.—Sectional View.
The Kirkwood Lead Burning Machine.

122

Fig. 46.—The Kirkwood Lead Burner.

A large charging screw is placed directly inthe top of the gas chamber. Into this is screweda tee and short nipple, or it may be a special fitting123made for that purpose. On this tee or specialfitting a pressure gauge is screwed, and afloat valve is attached on the branch. Into thegas chamber or as close to the partition as possiblean angle valve is placed.

To Operate.

To charge the apparatus the safety valve isremoved and the amount of the charge of acidulatedwater having been previously ascertained,the charge is poured into the acid chamberthrough the air pipe. The charge of spelter orzinc is placed in the gas chamber through thecharging screw on top of the gas chamber. Thepump is now attached to the air inlet cock witha short hose, and a few strokes of the pump willforce the acid up into the gas chamber until thezinc is completely submerged. The generationof gas will begin at once.

The cock on the burner is then closed untilthe necessary working pressure is obtained, whenit is ready for use. The pressure of gas can beregulated by setting the safety valve to blow offat a greater or less pressure, as desired. Theuse of the float valve is to prevent acid from beingforced out of the gas chamber and into thetube. If this happens, the valve floats up and instantly124closes the outlet, in which condition thevalve remains until sufficient gas is generated toforce the acid back into the acid chamber. Whenfirst charging the machine, acid should be forcedup into the gas chamber until this valve closes,as that will force all of the air contained in thegas chamber out through the tube, leaving onlypure gas in the generator. When the acid isspent it is easily removed from the generator byattaching the pump to the air inlet cock and forcingthe acid up into the gas chamber. The anglevalve is then opened, when the spent acid can bedrawn off into a pail or other receptacle. Thiswill not drain the acid chamber absolutely dry,but practically so.

When the operator ceases work, as for dinneror for any purpose, all that is necessary is to openthe air inlet cock and detach the hose from thegas outlet. The acid will return by gravity tothe acid chamber when generation ceases. Whenthe operator is ready to resume work a fewstrokes of the pump will start generation again.

The Burner.

The burner, shown in Fig. 46, which is themost important part of the apparatus, is also constructedon a principle not heretofore used on a125lead burning apparatus. It consists of a smalltube, to one end of which is screwed a small cock,similar to a pet cock. To the other end, at a convenientangle, is brazed the burner proper. Thisconsists of a needle point valve. The needle point,being about ½ inch long, is arranged so that thepoint can pass through the gas outlet about 1-16inch. This seems to spread the flame in such amanner that it absorbs sufficient air to reducethe flame. It can be regulated by drawing theneedle in or out, as the work requires. There isalso a tube arranged to act as a by-pass or subflame.By opening the valve on this by-pass apilot or subflame is maintained, which does awaywith the annoyance of having the flame pop outor become extinguished, as it is instantly ignitedagain by the subflame. In operating, the flameis held at such a distance from the work as experiencewill teach to be proper, or until the leadstarts to melt. It should fuse with that well-knownand instantly recognized bright appearancewhich indicates the nonoxidizing flame.

Any one who is used to handling the blowpipe can easily familiarize himself with this blowpipe. The maker claims that 2 quarts of vitriolwill serve to operate the apparatus for a day of8 hours on lead as heavy as 12-pound. I have no126doubt that it will do even more than the makersclaim for it. The apparatus is made in threesizes, adapted for different classes of work. Afterthe experience I have had with it, I feel sure thatany beginner can use this apparatus safely if heuses ordinary judgment and care in handling agas apparatus that needs common sense treatment.

The common blow pipe is a simple little toolthat is used in connection with an alcohol torchfor soldering the finest and most delicate piecesof jewelry, and constitutes the sole method of solderingused by Britannia workers and jewelers,and the fact that such a varied assortment ofarticles are soldered by the blow pipe processleads one to surmise that it can be used to advantageon coarser work. Though it is a familiartool to gas fitters, plumbers as a rule are ignorantof its use, and it is hard work to find onewho ever saw a blow pipe used on lead work. Itis an easy matter to become proficient in its use,and the trick of keeping up a steady blast, andbreathing regularly at the same time, is soonlearned, and, when once acquired, stays with youalways. This trick consists of making a bellowsof your cheeks and using your tongue as a valveto close the entrance to the throat, leaving thepassage from the nostrils to the lungs clear forbreathing purposes. The only things necessary128to purchase for practice are a common bent blowpipe, which can be had for about 15 cents, and acommon candle.

Fig. 47.—Position of Candle and Blow Pipe.

To operate: The candle should be lighted, andwhen it burns well and freely the tip of the blowpipe should be brought close to the flame andslightly above the wick,a, Fig. 45. Then blowlightly through the blow pipe, and a pointed clearblue flame from 1 to 2 inches long, which willburn paper or char wood at a distance of 6 or 8inches from the flame, will be the result. Theflame is hottest and best when it shows a perfectcone-shaped blaze, and is obtained by a verymoderate blast. The variation of the blaze canbe noted by commencing to blow very lightly andincreasing the pressure gradually. The flame129will then show all stages from a smoky flame toa long blaze that cannot be concentrated on anysmall surface. The little sharp tip is where thehydrogen burns, and is the hottest part of theflame, being the part that is used for soldering.

Now, having noted these peculiarities, andknowing the perfect flame by sight, we will proceedto acquire the steady blast. The blow pipeshould be held between the lips, which will forma tight packing around it, and must not come incontact with the teeth. The cheeks are then inflated,which will have a tendency to throw thetongue back to the throat and prevent the air inthe mouth from blowing out through the nose.Now, by contracting the cheeks, and throwingthe tongue slowly forward, the air will be forcedthrough the blow pipe. This action is assistedwhen exhaling air by the pressure of the lungs,but when inhaling air the muscular contractionof the cheeks is depended upon entirely for theblast.

The ability to keep up a steady blast is merelya trick, or knack, and is learned with a few hours'practice; when learned, the length of time thatthe blast can be kept up depends solely upon thestrength of the muscles of the cheeks of the operator.If these did not tire, the blast could be kept130up for an indefinite time. Having learned tokeep up the steady blast and get a perfect flame,the beginner will want to practice soldering. Theblow pipe method of soldering has for its rangeof work everything that can be soldered, fromBritannia metal to platinum, but the only metalsthat are used by the plumbers are tin and leadand their several compositions, so we will confineourselves to the study of those metals.

Kinds of Solder Used.

In soldering any metal the solder should beso proportioned that it will melt many degreeslower in temperature than the metal to be soldered.Otherwise it would be quite probable thatholes would be burned in the work before thesolder would melt. There are exceptions to thisrule, however; for example, lead burning, whereone piece of lead is fused to another. As alsowith Britannia metal, it can be, and is, solderedwith its own material, but it would be likely tohave holes burned in it occasionally, and to avoidthis a solder mixed for that purpose should beprepared. Two receipts are given here for quickmelting solders that are suitable for this work.The first is preferred, but the second will answerthe purpose.

131Solder No. 1: Procure 4 ounces of pure lead,4 ounces of pure tin, and 2 ounces of bismuth.The lead should be melted first and thoroughlystirred and cleaned. It should then be allowed tocool to the melting temperature of the tin, whichshould then be added. Lastly add the bismuth.The whole should then be stirred and poured intoa suitable mold into very thin strips, about thesize of a No. 8 wire, making strips of solder thatcan be rolled up and carried in the pocket.

Solder No. 2: This solder is composed of twoparts of tin and one part of lead. These shouldbe mixed as described above. To have successin making solders several points must be observed.The metal melting at the highest temperatureshould be melted first, which must thenbe allowed to drop to the melting temperature ofthe next metal to be added, and when ready topour into molds the mixture must be stirred, asthe specific gravity of the several metals differsconsiderably, and unless constant stirring is resortedto the mixture will partially separate uponcooling, and the result is an irregular solder thatwill not do the work.

Practicing the Blowing.

Now, for practice, take two pieces of ¼-inchlead tubing and prepare them as for a cup joint,132by spreading one end with the bending iron andrasping the other end to fit the cup, as shown ina, Fig. 33. Support them as you best can in anupright position. Flux the joint with rosin.Then take the solder in the left hand, set thelighted candle at the right hight and distancefrom the joint, as shown at B, Fig. 47, whichleaves the right hand free to manage the blowpipe. Then heat the joint with the flame, and,as it gets hot, touch the joint with the solder,and when it reaches the melting temperature ofthe solder a drop of it will detach itself and flowclear around the joint, making a smooth, cleanjoint that is stronger than the pipe itself.

Joints made in this manner present a handsomeand workmanlike appearance to the mechanicaleye. Practice diligently on the leadpipe until you have become so proficient that youcan flow the solder all through the joint withoutwithdrawing the flame. Then procure some ⅜-inchblock tin pipe, and, when that can be solderedperfectly, the beginner can consider himselfsufficiently proficient to practice on flat seamson Britannia metal.

Soldering Britannia Metal.

For working Britannia metal the candle cannotbe used, as the dripping grease will cover the133work and seriously interfere with the flowingsolder. The beginner must provide himself withan alcohol or kerosene torch. A good form oftorch, manufactured and sold for electricians'use, is shown in Fig. 48. The alcohol gives aclean flame, but by comparison is somewhat expensive.The kerosene gives a flame that can beconcentrated on a small surface with fully asmuch heat, and if care is taken to allow only theblue flame to touch the work, it is fully as cleanand cheaper.

Fig. 48.—Alcohol or Kerosene Torch.

Fig. 49.—A Specially Constructed Torch.

The burning kerosene torch gives off a dirtysmell and smoke, which makes it disagreeable to134handle, but this is a case of take your choice, andit is left to the beginner to use either, as they willboth do the work satisfactorily. It is also necessary,in doing this work, to have the blow pipeattached to the torch and connected to the mouthwith a piece of very small rubber tube. This willleave one hand free to apply the flux and hold thesolder. The flame can also be quickly placed inany position or directed to any portion of thework without allowing the work to cool. Thealcohol torch for this work should be so constructedthat it can be held in a horizontal or invertedposition without spilling the contents ofthe torch.

The handiest, as also the cheapest, torch tomake is the one shown in Fig. 49. It consists ofa can 3 inches high made in the shape of a frustumof a scalene cone. The tube B should be ¼inch in diameter, and must run parallel with theflaring side and extend half way to the bottomof the can, ase. Then, when the torch is tippedto solder horizontal work, the alcohol will flowinto the spacea, leaving the alcohol to supply thewick to be drawn up by capillary attraction. Thistube is made of ¼-inch brass tubing, bent toform an angle with the can, as shown.

135

Fig. 50.—Using the Torch on a Flat Seam.

A screw and cap with a seat, such as is usedon brass lamps, is obtained, and a hole punchedin the capc just large enough to receive the tubeB. The screw is soldered into the opening of thecan at D. The wick, which is formed of manystrands of candle wicking rolled tightly together,is pulled through the tube by means of a wirehook, and left sufficiently long to lie in the spacea, so that it will always lie in the alcohol. Thistube is placed through the hole at D, and allowedto project about ¾ inch outside of the can. Wickingis then wound around the tube and forcedinto the socket formed in the screw D. The capis then slipped over the tube atc, and screweddown tight on the wicking, which will make a136tight joint at D, and will hold the tube firmly inplace.

When necessary to fill the torch the tube caneasily be removed and the torch filled. A separatefilling screw can be used if desired. Evenwith this form of torch an excess of alcohol willoccasionally get into the wick when used in ahorizontal position and increase the size of theblaze. But when this happens the torch can bebrought to an upright position for a moment,which will drain the wick and bring the blaze toits proper size.

The blow pipe for this torch is made from apiece of very small copper or brass tubing. Theend intended for the tip should be bent to theangle required, as shown atf, Fig. 49. It shouldbe fastened to the torch by means of a clamp,g,soldered to the flaring side of the torch. Thisclamp should be so arranged that the blow pipecan be adjusted to the requirements of the blaze.This clamp consists of a short piece of brass. Ahole is drilled in one end to allow the blow pipeto pass through, while the other end is filed to fitthe bevel of the can to which it is soldered. Theblow pipe can be held in position with a wedge,or a hole can be drilled and tapped and a smallscrew inserted which will hold the blow pipe137firmly in place. The tip of the blow pipe shouldnot be larger than 1-32 inch. The rubber tubecan then be attached to the projecting end of theblow pipe ath, which is then ready for use.

Fig. 51.—Cutting Metal for a Butler's Pantry Sink.

Owing to the Britannia metal melting at sucha low temperature, it would be well for the beginnerto practice on pieces of 2-pound sheet lead.Seams on this class of work are made by buttingthe edges of the metal, as these seams are notsupposed to show. The seams are prepared bytruing the edges and then beveling the edges withthe shave hook so that when brought together aV-shaped groove is formed. This is then fluxedwith a small amount of powdered rosin. A dropof the quick melting solder is then melted fromthe strip and allowed to drop on the seam. The138flame is then applied to the sheets, and as thesolder flows the flame must be kept slightly inadvance of it, Fig. 50. Care must be taken toheat the sheets only enough to cause the solderto flow. Otherwise the seam will not appear full.The beginner should experience no trouble insoldering these lead seams, and when perfect controlof the torch and flame is had, pieces of Britanniametal should be substituted for the lead.These seams are prepared and fluxed just as forlead.

Britannia metal is fast becoming the favoritelining for splash and drip boards on butler's pantrysinks, as also for lining the work benches insaloons. It is soft enough to allow the most delicatechina to be laid on it without danger of chipping,and is also very easy to keep clean. It takesa high polish and always looks well. The methodof cutting the metal for a butler's pantry sink isshown in Fig. 51, the dotted lines showing theactual dimensions of the article to be covered,while the full lines show the laps required tocover the edges of the board. This metal isharder than lead, and will not dress smooth withthe dresser. Any uneven spots must be presseddown with a hot flatiron. The method of turningthe edges is shown ata. The bending iron isheated and rubbed over the edge, gradually turning139the edges until they are at their proper position.The iron must be constantly heated to insurethe best results, and if properly done nowrinkles will appear. A lined work bench isalso shown in Fig. 52, which shows the methodof putting in the bar washer. The sheet metalmust be cut and fitted to its place and all theseams possible should be soldered before placingthe metal in position. The edges should be tackedon the under side of the work, when practicable,with copper tacks.

Fig. 52.—A Lined Work Bench, with Bar Washer.

140Sooner or later the blow pipe solderer will becalled upon to make repairs on Britannia metal,and will be surprised to find that it will be impossibleto solder the metal, owing to the excess ofmoisture under it. The best way to overcomethis, which is practically the only trouble thatoccurs, is to cut out a small square patch. Theedge can be cleaned and a patch of new metalcarefully fitted into the hole. When ready to beginsoldering, a piece of blotting paper should beinserted between the patch and board. Thispaper will absorb all the moisture and allow theseam to be neatly soldered. The man who makeshimself familiar with the blow pipe and torchsoon finds himself in a different class from theordinary everyday mechanic, and if mechanicalability be accompanied with sobriety and stability,the possessor will always command a goodsteady income.

• Acid Chamber, Framing,109
• Acid Chamber Work,108
• Acid, How Applied,66
• Acids,20
• Action of Generator,66
• Addition of Acid,66
• Air and Gas, Regulating Volume and Pressure,74
• Air Holder,40
• Air Pressure,58
• Alcohol Torch and Blow Pipe,133
• Apparatus for Lead Burning,15
• Arsenic, Poisonous Flame,69
• Arsenic Released from Acid on Zinc,69
• Bellows Air Holder,49
• Blow Pipe,50,62
• Blow Pipe, Kirkwood,122
• Blow Pipe, Mouth,127
• Blow Pipe Practice with Candle,128
• Blow Pipe, Walmsley Compound,50
• Blue Vitriol or Copperas,56
• Bottom for Generator,35
• Britannia Metal for Repairing,140
• Britannia Metal Soft Soldering,132
• Britannia Metal Work,14,31,32
• Britannia Metal Work with Torch and Blow Pipe,132
• Burner, Kirkwood Lead,119
• Burner Tips,62
• Burns and Their Treatment,17
• Candle Blow Pipe Practice,128
• Care of Apparatus,68
• Cautions,16
• Charging and Cleaning Screws,26
• Charging Generator,64
• Chemical Tanks, How Lined,105
• 142Chipping Knife for Lead,110
• Cleaning Generator,67
• Colors of Flame,76
• Connecting Apparatus,55
• Cup, Scrubbing,56,68
• Cup, Scrubbing, How Made,70
• Cutting Heavy Lead Straight,110
• Explosions, What to Do When They Occur,17
• Fire Trap,56,68
• Flame Management,73
• Flame Under Different Pressures,74
• Flat Butt Seam,83
• Framing Acid Chamber,109
• Gas from Gasoline, How Generated,39,51
• Gas Pressure,58
• Gasometer Air Holder,46
• Generator, Charging,64
• Generator, Cleaning,67
• Generator Construction,26
• Generator Frame,30
• Generator Materials,30
• Generator Pipe, How Fitted,37
• Generator Seams, How Burned,36
• Horizontal Butt Seam,88
• Horizontal Lap Seam,93
• Hydrogen and Air, Effect of Mixing,24
• Hydrogen Apparatus, Special,119
• Hydrogen from Water, How Made,25
• Hydrogen Gas and Its Properties,18
• Hydrogen Gas, How Made,20
• Hydrogen Proved Lighter Than Air,23
• Illuminating Gas Burning,51
• Inverted Butt Seam,90
• Inverted Corner Seam,98
• Inverted Lap Seam,92
• Joint for Through Burning,102
• Kirkwood Blow Pipe,122
• 143Kirkwood Lead Burner,119
• Knife for Cutting Lead,110
• Lap Seam,82
• Lead Burning Explained,10
• Lead Headed Nail,117
• Lead Sheets for Tank,105
• Lining Chemical Tanks,105
• Mixing Fork,55,57,59
• Mouth Blow Pipe,127
• Nail, Lead Headed,117
• Pipe Seams,100
• Pressure for Working Gas and Air,58
• Repairing with Britannia Metal,140
• Round Pipe Butt Seam,100
• Round Pipe Lap Seam,103
• Round Pipe, Tee Joint,104
• Scrubbing Cup,56,68
• Scrubbing Cup, How Made,70
• Seam, Butt, on Round Pipe,100
• Seam, Flat Butt,83
• Seam, Horizontal Butt,88
• Seam, Horizontal Lap,93
• Seam, Inverted Butt,90
• Seam, Inverted Corner,98
• Seam, Inverted Lap,92
• Seam, Lap,82
• Seam, Lap, on Round Pipe,103
• Seam, Through, on Round Pipe,101
• Seam, Upright Lap,95
• Seam, Upright Butt,86
• Seams, Different Kinds of,80
• Seams, How Prepared,80
• Seams, Pipe,100
• Sink, Bar and Washer,138
• Sink, Butlers' Pantry,137
• Soft Solder,13,130
• Soft Solder Formulæ,131
• 144Solder, Soft,13,130
• Special Hydrogen Apparatus,119
• Staging for Acid Tank,115
• Straps for Tank Lining,111
• Tanks, How Made,12
• Tee Joint on Round Pipe,104
• Test for Hydrogen,21
• Testing Apparatus,56
• Through Burning, Joint,102
• Through Seam on Round Pipe,101
• Tips, Burner,62
• Tips, Sizes of,78
• Torch, Alcohol and Blow Pipe,133
• Trap, Fire,56,68
• Upright Butt Seam,86
• Upright Lap Seam,95
• Vitriol,56
• Vitriol Action on Zinc,69
• Walmsley Compound Blow Pipe,50
• Water Pressure Air Holder,42