Materials
What filler wire or rod for galvanised steel?
Quick answer
For galvanised steel use same as mild steel; silicon-rich wires handle zinc slightly better. Matching filler to the parent grade is the rule — mismatched filler either cracks, corrodes or underperforms the base metal.
Filler selection
- Process choice: flux-core or stick 6013/7018 on it, MIG if you grind the coating back
- Filler: same as mild steel; silicon-rich wires handle zinc slightly better
- Prep: grind the gal off the weld zone where you can — it's faster than fighting porosity
Why matching matters
Filler chemistry controls strength, corrosion behaviour and crack resistance. The classic Australian mistake is welding 316 stainless with 308 filler — it works, until the job sits in a coastal or chemical environment and the weld rusts first. When in doubt, weld with a filler at least as alloyed as the parent.