Materials

Preparing mild steel for welding

Quick answer

Prepare mild steel by cleaning grind back to bright metal at least 20 mm each side of the joint. On this material, cleanliness decides weld quality more than machine settings do.

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The prep routine

  • grind back to bright metal at least 20 mm each side of the joint
  • Clamp or tack so the joint can't walk as heat goes in
  • Check fit-up: gaps eat filler and heat control
  • For multi-pass, brush and inspect between passes