5.4 GAS WELDING
Basically, filler and base materials are heated to the point of melting by a burning a gas.
These are suited to a few applications, but they produce by-products that can contaminate the final weld.
Typically the flame is adjusted to give a clean burn, and this is applied to the point of the weld.
A welding rod will be fed in separately to melt and join the weld line.