Excessive current in FCAW can cause which problem?

• A. Convex beads with poor appearance and burn back into the contact tip
• B. Perfect beads
• C. No effect on weld
• D. Reduced penetration

Answer: (A)

Excess current in FCAW increases heat input, causing the weld pool to melt and advance too quickly. That extra heat tends to push the bead outward, producing a convex, poorly shaped bead with a rough appearance. At the same time, the intense heat can cause the electrode near the contact tip to melt back into the tip, a condition known as burn-back, which can foul the contact tip and disrupt the welding process. This combination—a overly convex bead with a burn-back issue—is a classic sign of too much current.

The other outcomes don’t fit because perfect beads require appropriate current control; no effect on the weld would ignore the obvious impact of excessive heat; and reduced penetration is typically associated with too little current, not too much.