Westwood High School - Chipmunk Yearbook (Westwood, CA)

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This view, taken from one of the watch towers, shows part of Westwood Lumber Yard.

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Oxy-Acetylene Welding and Cutting THE process of uniting metals by means of reducing the edges to be welded to a molten state, and uniting them without pressure or hammering is called autogenous welding. This is, at the present time, done either by means of the electric arc, or by the oxy-acetylene, and burning them, producing an intense- ly hot atmosphere immediately surrounding the spot to be welded. Acetylene is a gas, more or less familiar to all in lie form of Piestolite tanks, formerly used for lighting automobiles. This gas is made from calcium carbide, which is in turn produced in the electric arc. When water is applied to calcium carbide, a chemical reaction takes place in which calcium oxide, or common quicklime, is produced, while acetylene gas is freed. This gas is composed of hydrogen and carbon, both of which are very easily and completely oxidized, pro- ducing a very intense heat. However, when hydrogen and oxygen unite a certain temperature is reached at which the water formed by the reaction again decom- poses into hydrogen and oxygen. This is obviously the highest temperature possible to obtain with this reac- tion. and so in the oxy-acetylene torch the burner is so designed that only the carbon in the acetylene unites with the oxygen, while the hydrogen takes its oxygen from the air, thus surrounding the intensely hot core of the flame with an outer flame that prevents the metal being worked on, from being oxidized by oxygen in the air. Oxygen is one of the constituents of the air. and also of water, and commercial oxygen, for use in welding is produced from one or the other of these substances. In a cell especially designed to prevent the two gases from mixing, water is decomposed by electrolysis into hyd- rogen and oxygen. If the gases are not kept absolutely distinct and separate, an extremely explosive mixture is the result, which, after it is compressed into cylinders to be shipped, may explode, doing tremendous damage. It sometimes happens that several of these cells are connected up to a single compressor, and if the poles of the electrical circuit are reversed on one or more cells, it has the result of mixing the gases together. Another way of obtaining oxygen is by compressing and cooling air until it is liquid, when the nitrogen can be separated from the oxygen, having a lower boiling point. This is the safest way, as it is obviously impos- sible to mix any combustible gas with the oxygen. For a long time, although the process was known, oxy-acetylene welding and cutting was not extensively used because no satisfactory method had been found to transport acetylene gas, which cannot be compressed to more than fifteen pounds, without great danger. Then someone discovered that it could be dissolved in acetone, which would dissolve nearly two hundred vol- umes of it under considerable pressure, that being used at the present time being about 250 pounds per square inch. So the cylinders in which commercial acetylene gas is shipped, are not merely filled with the gas. nor are they content merely with acetone, as if that were the case, the acetone, being a liquid would run out if the cylinder were used in a horizontal position. So the cylinders are filled with asbestos, and arc tone is poured in until the asbestos is saturated, when the gas is punio- ed into the acetone. This makes it possible to safely ship a very large amount of gas in a small cylinder. Be- fore this was developed, acetlyene had to be produced on the individual job it was to be used on. by means of clumsy, expensive and unsatisfactory generators, which do not produce a gas pure enough to produce a good 23