Which is not recommended for FCAW welding?

• A. Constant current
• B. Short-circuit transfer
• C. Spray transfer
• D. Pulsed mode

Answer: (A)

In FCAW you want a steady arc that stays consistent as you move, and that’s achieved most reliably with a constant voltage power source. Setting the voltage establishes the arc length, and the wire feed rate can then adjust the current to maintain that arc. Using a constant current source doesn’t regulate the arc length, so the arc can wander, causing inconsistent penetration and bead shape, more spatter, and heat control problems. That’s why constant current is not recommended for FCAW. The other options—short-circuit transfer, spray transfer, and pulsed mode—are common FCAW modes: short-circuit transfer uses lower heat for thin sections and position welding, spray transfer delivers a smooth, high-deposition weld on thicker sections with higher current, and pulsed mode modulates current to balance heat input and penetration, reducing distortion while keeping good weld quality.