C. H. Fay

“ Hydrogen does not spontaneously enter into reaction with any of the elements, although it has a powerful affinity for several of them. Thus, when hydrogen and oxygen are mixed nothing occurs, but if a lighted splint is introduced a violent explosion ensues, water being produced. Similarly chlorine and hydrogen are without action upon each other in the dark, but if the mixture is exposed to a bright light, or if heated by the passage of an electric spark, the gases are at once combined with explosive violence, forming hydrochloric acid. ”

“ Having learned to keep up the steady blast and get a perfect flame, the beginner will want to practice soldering. The blow pipe method of soldering has for its range of work everything that can be soldered, from Britannia metal to platinum, but the only metals that are used by the plumbers are tin and lead and their several compositions, so we will confine ourselves to the study of those metals. ”

“ To make a really strong seam it must be gone over with the flame at least twice, as after fusion of the edges takes place the flame can be used quite strong without fear of the lead running from the seam. Do not leave this seam until you are satisfied that it is nearly perfect. It is good practice, and every hour spent only makes the mastery of the next seam come so much more quickly. ”

“ This is probably the origin of the apparent secrecy with which a lead burner usually surrounds himself.
If an explosion should occur in the tubes and they should catch fire, the operator must have presence of mind enough to reach the gas cock on the generator and close it. If gas explodes in the generator, all that can be done is to dodge the flying pieces and make a new generator. If such an incident should occur and vitriol should spatter on the person doing the work, or his assistant, a solution of bicarbonate of soda or common washing soda should be at once applied to the wounds. ”

“ By forcing air into and through a body of gasoline sufficient of the gasoline is taken up to form a dense vapor, which will light and burn at the jet, similar to illuminating gas. With the admixture of air in the compound blow pipe, it gives a flame of very intense heat. But, in common with illuminating gas, it is so rich in carbon that it gives an oxidizing flame, and makes it necessary to use a flux, which should be Yager's soldering salts mixed as per the directions on the bottle. ”

“ There is no royal road to this business; but practice, and practice hard, is the only way to satisfactorily master the blow pipe and flame, and in practicing remember that all this work has been done before, and can be easily done again, and by you. Do not get discouraged by failure to make a perfect seam at the first application, but stick to it for a short time and it will be found to be a most fascinating pastime, for which the persistent student will eventually be well repaid. ”

“ The chief danger with an apparatus of this sort is its liability to accident by the careless use of the gas, and, as a mixture of hydrogen and air is very explosive, great care must be taken to exhaust all the air in the generator and tubes before attempting to light the gas at the blow pipe. The only way to make sure that the air is exhausted is to test the gas, as described under the head of “The Flame and Its Management.” ”

“ Under no circumstances must the apparatus be left until there is absolutely no doubt as to its being perfectly tight, as a slight leak would be likely to cause a disastrous explosion and injure or probably blind the operator. Flying vitriol is not a very pleasant thing to get in one's eyes.
The apparatus should be frequently tested in this manner: Before drawing off the water it is desirable to learn what amount of gas pressure there will be when the generator is charged, so that the pressure of air and gas can be equalized. ”

“ No rule can be given for cutting lead to fit a tank, as tanks are of such a variety of sizes and shapes, and the lead is of so many widths, that the mechanic must study how to cut the stock without waste and have as few seams as possible. ”

“ The beginner will observe from the above that the generator cannot be crowded by making the acid solution strong. Hydrogen is a peculiar gas and also a dangerous one for one ignorant of its peculiarities to experiment with, and in order to thoroughly understand it the following experiments should be demonstrated, which can be done with little expense. ”

“ To generate gas from gasoline is a simple operation. To do this, take a common 1-gallon oil can, remove the top of can screw and punch a 1⁄4-inch hole in the center of it. Then make a tube of tin that will pass through this hole, sufficiently long to extend half way to the bottom and project 2 inches outside of can screw, and solder this tube in place. This projecting tube is for the purpose of connecting to the air holder. Remove the spout of the can and replace it with one to which the hose can be connected. ”

“ Before attempting to burn the generator the beginner should practice on pieces of sheet lead. It is next to impossible to burn seams in any other position than horizontal with this flame, as it rapidly oxidizes the lead, and in spite of all precaution the lead will become unmanageable in upright seams, so that the beginner would waste time in practicing on seams in any other position than horizontal. ”

“ The strip is laid flat on the lead sheet, with the bevel end down, and is then burned onto the sheet in that position, after which it is bent over the studding and nailed. The exponents of this method claim that a better job is done in that manner, as there is always a lifting pull on the strap. I claim for the first method that there is more strength in the lead seam, and that as the edge of the studding comes directly under the strap it acts as a sort of shelf for the strap and thereby becomes a strong brace. But it is probably only a matter of habit, as they hold all right either way. ”

“ Thrust a lighted splint into the bottle. The gas will light and burn at the mouth of the bottle. If the splint is thrust far into the bottle it will go out. Drops of water collect in the bottle. Burning is a union with oxygen; therefore, the burning of the hydrogen shows that it has an affinity for oxygen. The splint goes out because the hydrogen does not support combustion. If no air is allowed to get into it the gas cannot burn or explode.
Fig. ”

“ The pure gas is not absolutely essential for lead burning, and owing to their being much cheaper, and also on account of their increased quickness of action, the commercial qualities of sulphuric acid and zinc are employed in the generator described. ”

“ The lead for this form of seam is prepared, as its name indicates, by lapping one sheet 1⁄2 to 3⁄4 inch over the other sheet. The under edges are to be shaved clean, as also the upper edge. The lead required to make the seam is melted from the upper lap and is fused on the lower sheet. There is no reason why the lead at the point of juncture cannot be made as thick as the original lead. This is the point aimed at in practicing, and the only accurate way to determine the relative strength of the seams is to cut squarely across a finished seam, then bend the beam slightly. ”

“ The combination of acid and water enters at once into reaction and always generates heat, and the result of adding water to acid would be small explosions. There would be danger of the acid flying on one's clothes or into the eyes. The mixture should never be stronger than six parts of water to one of acid. ”

“ This form of flat seam should be practiced until perfectly familiar with the blow pipe flame and until the beginner can approach the lead with the flame without burning holes through it, which will probably be the first thing to happen.
Upright Butt Seam. The upright butt seam is seldom used on large work, as it is a difficult matter to make an upright butt seam that will stand the test, as, if a finished seam is cut into short pieces, an examination of the severed ends will show many weak places that were previously thought to be very strong. ”

“ The only way to determine the size of the flame necessary is by experimenting with it. It will also come with experience. The flame should be reduced to a size that will not melt the lead as soon as it touches it. Rather, it should be in such condition that the lead would have to be heated first and let the fusing come gradually. ”

“ Tanks used for the above purposes must be lined with lead and the seams burned, as acids attack the tin in solders and destroy them. The demand for the work is rapidly increasing where it is introduced. I have demonstrated to many manufacturers that this is the cheapest method known, as it gives a permanent solution of the problem how to keep a chemical tank tight. ”

“ The edge can be cleaned and a patch of new metal carefully fitted into the hole. When ready to begin soldering, a piece of blotting paper should be inserted between the patch and board. This paper will absorb all the moisture and allow the seam to be neatly soldered. The man who makes himself familiar with the blow pipe and torch soon finds himself in a different class from the ordinary everyday mechanic, and if mechanical ability be accompanied with sobriety and stability, the possessor will always command a good steady income. ”

“ The advantage of the bellows is that it can be easily transported and does the work perfectly, but it requires constant pumping, which soon tires the helper, and for that reason could not be used on jobs requiring more than four or five hours' labor.
The gasometer style of air holder is the easiest to use, if one does not employ a helper and has a large amount of work to do. The pressure can be regulated to suit the work by placing one or more weights upon it until the desired pressure is obtained. ”

“ This form of generator will never blow acid like the floating generator.
The requirements of a hydrogen generator for lead burning are that it should be safe, economical 16and automatic in its action. It must be so constructed that it will generate gas enough to keep the supply constant, and deliver it at sufficient pressure to keep the flame steady. It must also be provided with a combination fire trap and scrubbing cup. This will prevent the explosion of the generator by firing the gas in the hose. This trap must be partly filled with a solution of blue vitriol to act as a precipitation cup. ”

“ The hight of liquid in the generator measured from the bottom of the acid supply pipe to the top of the water or acid line, when at its highest level, would be 3 feet. Allowing 1⁄2 pound for every foot in hight would give a pressure of 11⁄2 pounds, which is slightly in excess of the mathematical rule, which is 3 × 0.434 = 1.302, or 1 pound 4 ounces, but to be accurate it is well to attach a mercury gauge to the gas cock. ”

“ Study the Chapter on Hydrogen Gas. I cannot too strongly recommend that the beginner study the chapter on hydrogen gas until the main points are memorized and clearly 10understood. The experiments should be performed and the result carefully noted for future reference before attempting to use the generator. It is time well spent to master the technical parts thoroughly before attempting the mechanical part. Then when a man takes up the mechanical he will do so with an intelligent understanding of what he is doing, and any little trouble which may then arise can be quickly overcome. ”

“ It is a very sensible idea to keep spectators away from the generator, as they are very apt to strike matches or tread on the tubes, in spite of warnings to be cautious, for if there should be a leak, even so slight as to be hardly detected, it would cause a violent explosion, and as hydrogen 17is both odorless and colorless, this could easily happen without being noticed. ”

“ The metal melting at the highest temperature should be melted first, which must then be allowed to drop to the melting temperature of the next metal to be added, and when ready to pour into molds the mixture must be stirred, as the specific gravity of the several metals differs considerably, and unless constant stirring is resorted to the mixture will partially separate upon cooling, and the result is an irregular solder that will not do the work. ”

“ Hydrogen is obtained by the decomposition of water in various ways. On a large scale, nearly pure hydrogen may be prepared by passing steam over charcoal, or coke, heated to a dull redness. If the temperature be kept sufficiently low hydrogen and carbon dioxide will be the sole products, and the latter may be removed by causing it 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 monoxide 19is also produced, and cannot be removed from the mixture. ”

“ The air should then be admitted gradually until the flame is brought to the proper size and condition, indicated by its being blue and pointed. If too much gas is admitted the flame will be yellow 53and will blacken the work by depositing a coat of soot on it. If too much air is admitted the flame will be ragged and noisy, and the temperature will be too low to heat the metal. The flame is at its best heat when it burns with a pale blue color which does not show any yellow streaks. ”