Troubleshooting

Why is my tig welding lack of fusion?

Quick answer

Lack of fusion in tig welding usually means too cold, too fast, or welding over mill scale without penetration. For this process, establish the pool before travelling before touching anything else.

· · Technical guidance compiled from trade practice and manufacturer data; our source-verification program is in progress — see our editorial policy.

The specific fix

Establish the pool before travelling. The general rule: raise amps, slow travel, grind to bright metal, watch the wetting at the edges.

Process checklist

  • Dipping the tungsten into the pool — contaminating the electrode and the weld
  • Too much torch angle: 10–15° from vertical is plenty
  • Forgetten post-flow gas: tungsten oxidises and turns black as it cools