Which statement is NOT a characteristic of CO2 shielding gas when used with short-circuit transfer?

Which statement is NOT a characteristic of CO2 shielding gas when used with short-circuit transfer?

• A. Deep, narrow penetration pattern.
• B. High weld metal loss in the form of spatter.
• C. Excellent surface cleaning action.
• D. Shallow, wide penetration pattern.

Answer: (C)

The main idea is how shielding gas shapes the arc and the weld bead in short‑circuit transfer. CO2 creates a hotter, more unstable arc that tends to penetrate more deeply and in a narrower path, and it usually comes with more spatter and a rougher surface. It does not provide cleaning action on the weld surface; in fact, the oxide on the metal is more likely to persist or worsen with CO2 shielding, so you don’t get the cleaning effect some other gas blends can offer. So the statement about excellent surface cleaning action isn’t a characteristic of CO2 shielding.

The main idea is how shielding gas shapes the arc and the weld bead in short‑circuit transfer. CO2 creates a hotter, more unstable arc that tends to penetrate more deeply and in a narrower path, and it usually comes with more spatter and a rougher surface. It does not provide cleaning action on the weld surface; in fact, the oxide on the metal is more likely to persist or worsen with CO2 shielding, so you don’t get the cleaning effect some other gas blends can offer. So the statement about excellent surface cleaning action isn’t a characteristic of CO2 shielding.