This difficulty can be eliminated
by backing up the weld with a metal face or by decreasing the intensity of
the arc so that this melting through will not occur. However, the practical
limit for arc welding without backing up the work with a metal face or
decreasing the intensity of the arc is approximately 22 gauge, although
thinner metal can be welded by a very skillful and careful operator.
One difficulty with arc welding is the lack of skillful operators. This
method is often looked upon as being something out of the ordinary and
governed by laws entirely different from other welding. As a matter of
fact, it does not take as much skill to make a good arc weld as it does to
make a good weld in a forge fire as the blacksmith does it. There are few
jobs which cannot be handled successfully by an operator of average
intelligence with one week's instructions, although his work will become
better and better in quality as he continues to use the arc.
Now comes the question of the strength of the weld after it has been made.
This strength is equally as great as that of the metal that is used to make
the weld. It should be remembered, however, that the metal which goes into
the weld is put in there as a casting and has not been rolled. This would
make the strength of the weld as great as the same metal that is used for
filling if in the cast form.
Two pieces of steel could be welded together having a tensile strength at
the weld of 50,000 pounds.
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