more vivid color, and its tip
begins to whip about. When the flame is at its highest temperature it
will produce a hissing sound and the inner cone will be short and
bright. With a softer flame, which has a temperature suitable for
welding plates to a strap, the inner cone will be longer and less
vivid, and the hissing will be greatly diminished.

The temperature of the different parts of the flame varies
considerably, the hottest part being just beyond the end of the inner
cone. Experience with the particular welding outfit used will soon
show how far the tip of the torch should be held from the lead to be
melted.

Cleanliness. Lead surfaces which are to be welded together must be
absolutely free from dirt. Lead and dirt will not mix, and the dirt
will float on top of the lead. Therefore, before trying to do any lead
welding, clean the surfaces which are to be joined. The upper ends of
plate lugs may be cleaned with a flat file, knife., or wire brush. The
posts and inter-cell connectors should be cleaned with a knife, steel
wire brush, or triangular scraper. Do not clean the surfaces and then
wait a long time before doing the lead burning. The lead may begin to
oxidize if this is done and make it difficult to do a good job.

The surfaces which are to be welded together should also be dry. If
there is a small hole in the top of a post which is to be welded to a
connector or terminal, and this hole contains acid, a shower of hot
lead may be thrown up by the acid, with possible injury to the
operator.

Do not try to save time by attempting to weld dirty or wet lead
surfaces, because time cannot be saved by doing so, and you run the
risk of being injured if hot lead is thrown into your face. Remove
absolutely every speck of dirt--you will soon learn that it is the
only way to do a good job.

Safety Precautions. Remove the vent plugs and blow down through the
vent holes to remove any gases which may have collected above the
surface of the electrolyte. An explosion may result if this is not
done. To protect the rubber covers, you may cover the whole top of the
battery except the part at which the welding is to be done, with a
large piece of burlap or a towel which has been soaked in water. The
parts covered by the cloth must be dried thoroughly if any welding on
them. Instead of using a wet cloth, a strip of asbestos may be laid
over the vent holes, or a small square of asbestos may be laid over
each vent hole.