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 top of the can C, Fig. 9, with the air holder D, then connect the spout or gas outlet e of the can to the gas end f of the compound blow pipe. The air outlet g of the compound blow pipe should then be connected to the remaining cock h, in the air holder. If the bellows is used, it will be necessary to connect the air with ¼-inch tee, m, in which three short nipples have previously been screwed.
The apparatus is now ready for use. Gasoline being really a liquid gas, it takes its first opportunity to assume its natural shape. The natural way to convert gasoline into gas is by simple evaporation. So taking advantage of this fact, the action will be thus: 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. If this is difficult to procure, a good substitute can be made by mixing equal parts of powdered borax and sal ammoniac in a little water.
To operate this device the air should be turned on the gasoline and lighted at the jet. 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 and 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.
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. If directions have been followed in cutting the lead for the generator the seams will occur only in that position.
To burn the generator the seams should be shaved clean, both on the under and upper sides, for a distance of ⅛ inch, making a seam ¼ inch wide, taking care to have the lead seams lie close to each other, for, if they do not, this flame will cause the edges of the lead to spread away from each other and leave a hole that is difficult to patch.
Now apply the flux with a small brush. When the flame is in working order bring it quickly to bear on the end of the seam nearest you to be burned. When it starts to fuse draw the flame as quickly away, always drawing it to one side, and from the upper to the lower sheet. The melted drop will follow the flame and unite with the melted drop on the lower sheet.
It is necessary to have the shave hook near at hand, so that, in case of oxidizing when fusing, the melted drop can be broken up and allowed to flow in place.