Which statement best distinguishes FCAW from GMAW?

• A. GMAW uses a flux-cored wire; FCAW uses a solid wire with external gas
• B. FCAW uses a flux-cored wire that can shield with shielding gas or be self-shielded; GMAW uses a solid wire with external shielding gas
• C. FCAW uses gas-only shielding; GMAW uses flux core shielding
• D. FCAW cannot be used for field repairs; GMAW is always field repair friendly

Answer: (B)

The main idea is how shielding is provided and what the electrode is made of. Flux-cored arc welding uses a tubular wire filled with flux. That flux supplies shielding either by generating a shielding gas when burned (gas-shielded FCAW) or by producing slag and gases that shield the weld even without external gas (self-shielded FCAW). Gas metal arc welding uses a solid wire with no flux; shielding comes from an external gas supply through the torch (such as argon, CO2, or a mix). So the statement that FCAW uses flux-cored wire that can shield with shielding gas or be self-shielded, while GMAW uses a solid wire with external shielding gas, correctly captures the key distinction. The other options mix up which process uses flux or gas shielding, or introduce incorrect claims about field repairs.