nd to give the
compound a smooth glossy finish. These processes are not welding
processes and will not be described here.

General Lead Burning Instructions

Flame. With all the lead burning outfits, it is possible to adjust the
pressures of the gases so as to get extremely hot, medium, and soft
flames. With the oxygen-acetylene, or oxygen-hydrogen flame, each gas
should have a pressure of about two pounds. With the
oxygen-illuminating gas flame, the oxygen should have a pressure of 8
to 10 pounds. The city gas then does not need to have its pressure
increased by means of a pump, the normal pressure (6 to 8 ounces)
being satisfactory.

Various makes of lead-burning outfits are on the market, and the
repairman should choose the one which he likes best; since they all
give good results. All such outfits have means of regulating the
pressures of the gases used. With some the gases are run close to the
burning tip before being mixed, and have an adjusting screw where the
gases mix. Others have a Y shaped mixing valve at some distance from
the burning tip, as shown in Figure 78. Still others have separate
regulating valves for each gas line.

With these adjustments for varying the gas pressure, extremely hot,
hissing flames, or soft flames may be obtained. For the different
welding jobs, the following flames are suitable:

1. A sharp, hissing flame, having a very high temperature is the one
most suitable for the first stage in welding terminals and connectors
to the posts.

2. A medium flame with less of a hiss is suitable for welding plates
to strips and lengthening plate lugs.

3. A soft flame which is just beginning to hiss is best for the
finishing of the weld between the posts and terminals or connectors.
This sort of a flame is also used for finishing a sealing job, drying
out the cover channels before sealing, and so on.

In adjusting the burning flame, 4 the oxygen is turned off entirely, a
smoky yellow flame is obtained. Such a flame gives but little heat. As
the oxygen is gradually turned on the flame becomes less smoky and
begins to assume a blue tinge. It will also be noticed that a sort of
a greenish cone forms in the center portion of the flame, with the
base of the cone at the torch and the tip pointed away from the torch.
At first this inner-cone is long and of almost the same color as the
outer portion of the flame. As the oxygen pressure is increased, this
center cone becomes shorter and of a