Troubleshooting
Why is my flux-core welding lack of fusion?
Quick answer
Lack of fusion in flux-core welding usually means too cold, too fast, or welding over mill scale without penetration. For this process, more amps, slower travel before touching anything else.
The specific fix
More amps, slower travel. The general rule: raise amps, slow travel, grind to bright metal, watch the wetting at the edges.
Process checklist
- Wrong polarity — most gasless wire wants DCEN (electrode negative); check the packet
- Dragging the gun like stick — gasless likes a slight drag angle, unlike gas MIG
- Leaving slag-capped wormholes by welding too slow or too hot