Materials
Common problems when welding mild steel
Quick answer
Common mild steel welding problems: porosity from dirty steel, burn-through on thin sheet, and cold laps from too little heat. All three are preparation and settings issues, not metal problems.
Problem → cause → fix
| Symptom | Cause | Fix |
|---|---|---|
| Porosity | oils, paint, scale | grind 20 mm either side |
| Burn-through | too hot/slow on thin | drop amps, stitch weld |
| Cold lap | too cold/fast | raise amps, watch wetting |