Flux-Cored Arc Welding, or “FCAW,” is very similar to MIG welding; however, it features the use of a special tubular wire that is filled with flux. The flux may be sufficient by itself to protect the welding puddle from contamination or a shielding gas may also be used, depending on the filler material and other circumstances. FCAW is commonly used for welding thick sections of steel and stainless steel, as well as for welding in outdoor and windy environments, due to the self-shielding capability of flux-cored wire.