TIG welding cast iron??

Not so much TIG welding as TIG brazing with pure nickel filler rod.

First, grind prep all surfaces to be welded. You want deep V grooves at the joints. Preheat the whole piece in an oven to about 500 degF.

Using Pure Nickel (aka Nickel 99) filler rod and only enough heat to perform the task, lay in short 1/2" stitch welds. You are trying here to NOT melt the base metal if possible. Just fuse the Nickel to it. Peen the welds lightly with a small hammer as they cool. This helps stretch them out so the weld shrinkage doesn't cause cracks. Eventually go back in and fill in the gaps between the stitches.

After the entire seam is welded, wrap the piece up or bury it in something so it cools very slowly.

"Ernie Leimkuhler" wrote: (clip) Not so much TIG welding as TIG brazing with pure nickel filler rod. (clip) ^^^^^^^^^^^^^ For years I always brazed cast iron with brass filler, until I discovered nickel arc welding rod. Now, your discussion has me wondering. Does nickel make a better filler for A/C brazing than brass?

Nickel is stronger than brass and works quite well for stick welding and TIG welding cast iron. I have done both. I find TIG allows me to control the heat better.

Thanks for the help with this, I'll practice with Nickel on a scrap manifold, and if I chicken out I'll pay someone with more experience to do the "proper" one. Thanks again!