I posted in general discussion, and thought ,I would put in here for better response. Question is, whats the best rod to weld cast iron and does it need to be preheated or anything need to be done.

Whats your application?

TIG or Stick, use a SS rod, or pure nickel if you can get it, but you have to pre-heat and post-heat to have a chance at getting away with it.

True cast iron welding is done at 1300*, you need an induction table to maintain that.

Thanks, MC for the info.