rod of choice for cast iron on AC?

[tb525]

Try Certanium 790 or 7500.. For dirty/rusty cast use 777..

 

[yomax4]

309 Stainless has always been the rod for joining Steel to Cast. If you want to try another Wonder Rod to weld any Steel to anything else other than Aluminum and other Non Ferrous materials.. Try 312 Stainless. Problem Solver..:thumbsup:

 

[Soundguy]

I believe I will be looking for some locally as well.

soundguy

 

[yomax4]

Remember when weldig Cast with a Stick Rod..You Must, You Must You Must. Drill a hole at each end of the crack or it will spread on it's way. Weld or no weld.

 

[Gary Fowler]

Some of the materials that we think are cast iron are actually cast steel and can be welded even with mild steel rods and hold quiet well. There is probably not much cost difference in 309 or any 300 series stainless rod and Ni-rod but stainless will certainly weld better than the ni-rod which kind of globs off the end and the flux is so thick that it is hard to see the weld puddle. Every one has the right idea with preheat and slow cool. Peening would also likely help relieve the stresses to prevent post weld cracking.