During a multi-pass FCAW-G weld on a thick-plate butt joint, a welder experiences consistent porosity in the root pass. The base material is clean, and the shielding gas flow rate is correct. Which adjustment should the welder primarily consider to eliminate this root pass porosity?

Question: During a multi-pass FCAW-G weld on a thick-plate butt joint, a welder experiences consistent porosity in the root pass. The base material is clean, and the shielding gas flow rate is correct. Which adjustment should the welder primarily consider to eliminate this root pass porosity?

Answer options:

• Increasing the arc voltage
• Decreasing the wire feed speed ✅ Reducing the wire stick-out
• Increasing the preheat temperature

Correct answer: Reducing the wire stick-out

Explanation: Reducing the wire stick-out (distance from contact tip to workpiece) increases the current for a given wire feed speed, leading to a hotter, more concentrated arc with better penetration and gas shielding effectiveness at the root. This helps to burn out contaminants and prevent porosity. Increasing arc voltage or decreasing wire feed speed would generally increase arc length or reduce current, potentially worsening porosity by reducing penetration or increasing atmospheric exposure.