How To Weld Cast Iron Video. Dont heat over 1400 degrees F since that will put the material into the critical temperature range. If youre welding up a machined surface the best option would be to TIG weld it.
At this temperature the iron inside the metal gets stretched preventing it from cracking. Take your time heating it up make sure its slow and even. Clean the slag in between the welding process and peen each weld bead.
The casting must be completely clean in the area of the weld.
Welding that hot bad. Preheating and slow cooling of the component is the crux for the cast iron welding procedure. Watch this video of Cast Iron Wheel Repair to understand the process clearly. Ideally heat up the entire part.