mig welding ss with mild steel catalytic converter

By case310350 Date 06-21-2008 15:29

my son ripped off the catalytic converter on his car. its welded right to the manifold. Cannot buy used so want to try and repair. I have a mig welder and want to try and weld it. I know preheat, weld, slow cool, and pean. will this work or will it crack? do i need stainless wire and argon oxy gas?

By Tommyjoking (****)

Date 06-22-2008 12:20 Edited 06-22-2008 12:33

what is the manifold material? Is it a cast Iron? A cast steel? Is the converter pipe may very well be a form of SS....check it with a strong magnet to be sure. If you are sure both pieces are steel whether cast or not you can join them with standard er70s or er80s wire. If the manifold is cast iron I am not aware of a suitable gmaw wire for joining the two metals, that sure don't mean there is not one. DID it break right against the manifold? if not why not just sew up the tube itself if its not to damaged.

By Kix

Date 06-24-2008 13:34

It sounds like he is talking about cast iron from the procedure he described, but ya never no heh. If it is cast and I only had a mig welder, I would weld it with ER309L stainless wire with all the preheat and post weld heat goodies. I always TIG weld my cast iron mani's with ER309L wire.

By Metarinka (****)

Date 06-24-2008 14:33

yah I was taught to repair weld cast iron with stainless or nickel filler, If it's a small manifold might be better to grab a friend and weld it hot, I'm too impatient to weld an inch at a time