115 volt welders may require a conversion kit and may also require the ________ to be switched for Collision Repair welding.

• A. Voltage
• B. Polarity
• C. Feed Rate
• D. Shielding Gas Type

Answer: (B)

The important idea here is polarity—the direction of the electrical current relative to the electrode. In MIG welding on a 115V unit, switching polarity changes which lead is positive and which is negative, and that dramatically affects how the arc behaves with different filler wires. Solid-wire with shielding gas is typically run with the electrode positive, while flux-core or self-shielded wire often works best with the electrode negative. A conversion kit may include the parts needed to swap these connections so you can use the correct wire type and process for collision repair welding. Voltage, wire feed rate, and shielding gas type are set separately and don’t rely on a polarity swap in the same simple way.