Troubleshooting

Why is my tig welding sugaring?

Quick answer

Sugaring (stainless) in tig welding usually means back side of the stainless weld oxidising from no shielding. For this process, back-purge the joint before touching anything else.

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The specific fix

Back-purge the joint. The general rule: purge the back of the joint with argon or use a backing flux paste.

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