What is the recommended electrode wire for collision repair welding?

• A. ER70S-2
• B. ER92S-6
• C. ER70S-6
• D. ER4043

Answer: (C)

Welding filler for auto-body steel needs to tolerate surface contamination—paint, rust, oil, and scale—while still providing a strong, ductile joint. ER70S-6 fits that requirement best. It’s a general-purpose low-carbon steel wire with higher deoxidizers (like silicon and manganese), which helps break up oxide layers, improve wetting, and reduce porosity when you’re welding through dirty or slightly oxidized surfaces common in collision-damaged parts. It also balances toughness and strength well for typical automotive steels, making it a reliable all-around choice for collision repair.

The other options aren’t as suitable for standard auto-body steel. ER70S-2 has fewer deoxidizers, so it’s less forgiving of surface contamination. ER92S-6 is formulated for different alloys (not the common mild steels used in body work), and ER4043 is an aluminum filler, not appropriate for steel.