Could I MIG weld two different types of stainless exhaust with good results?
I want to weld on BMW exhaust tips to a ractive stainless muffler. The muffler has no magnetic attraction. I,m assuming that means its very stain resistant like food grade stainless. The BMW tips have some magnetic attraction. I,m worried that It will have pin holes and it will need to be ground down and repaired.

Or should I have it TIG welded by a pro?


also why do the welds have green stuff on them?

 

Yeah, the 300 series wire will weld 409 to 304 just fine. Mig welding with 308 or even 309 .035" wire will work great. Mild steel is of course not recommended.

 

I have welded the low grade stainless exhaust stuff before with a MIG and mild steel wire and it turned out nice, no cracking issues. The welds are a flat dull finish, but it works well. In your case it is probably better to use a stainless wire and some argon though. The only issue that you could run into is vibration causing cracks in the welds, but I doubt that would be an issue as long as you go decent penetration, since the tailpipes are really short and there isn't a bunch of leverage.

 

Till it rusts, lol.

 

As far back on the exhaust system as the tips are you can clean the weld with a wire brush and then use a high temp black paint to protect the welds. It works great.