Anyone know how to weld new flanges on old cats?

[Kernal]

Does anyone know if new flanges can be welded to original cats (with corroded flanges on a FZJ-80). Any special tips or technique to do that, type of welding rod, etc?

 

[Pin_Head]

OA is very good for welding rusty muffler pipe. If I had to stick weld it, I would go with 6011 unless there is enough metal to grind it clean..

 

[Kernal]

I forget now, which type of stainless steel are the original pipes and cats from an 80 series, and what is OA? Would either of these work: 409 Cb, AWS ER430, W18 Cr-Cb filler wires? IDK.