TIG welding thin sheet without burn-through
Thin material burns through quickly and distorts. With the right settings and a calm way of working it comes out neat. Here is what to look out for.
Settings for thin sheet
- Current: start low and build up calmly. Thin material heats up quickly, especially stainless.
- Electrode: a thin electrode of 1.0 or 1.6 mm gives a narrower, more focused arc.
- Cup and gas: a smaller cup and a gas lens help keep the gas close to the weld pool.
- Pulsing: if your machine can do it, pulsed current helps limit the heat. The weld pool solidifies for a moment each time.
Way of working
1. Make the joint fit well. A gap is hard to bridge and leads to burn-through.
2. Tack often and close together, so the material cannot move.
3. Weld in short steps and let the work cool in between.
4. Use a copper backing bar or clamps to draw heat away.
5. Keep the arc short and keep moving.
Common mistakes
- Burn-through: the current is too high or you stay too long in one spot.
- Distortion: too much heat went in at once. Weld in steps and spread the heat.
- An unstable arc: check the electrode and the collet. See TIG welding problems and how to fix them.
Parts that help
A small cup, a gas lens and a sharp electrode make thin work easier. Not sure which parts fit your torch? Use our selection guide or send us a message via the contact page.