Materials
What filler wire or rod for cast iron?
Quick answer
For cast iron use ENiFe-CI (nickel-iron) rods; plain steel rods crack. Matching filler to the parent grade is the rule — mismatched filler either cracks, corrodes or underperforms the base metal.
Filler selection
- Process choice: stick with nickel (ENiFe) rods, low and slow with preheat
- Filler: ENiFe-CI (nickel-iron) rods; plain steel rods crack
- Prep: grind the casting skin off, drill small stopper holes at crack ends
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.