MIG Weld a Stainless Steel Exhast system

[vancouver67]

Has anyone here ever MIG welded their own Stainless Steel exhast system?

If so can you answer a few questions:

1) how was the finished product? Would you do it again?
2) Which gas mixture did you use Argon/o2 or trigas
3) What stainless wire did you use (material and dia)
4) Any tips that would be helpful.

I am just deciding if this is something I should tackle?

[parsonsj]

I've MIG-welded several exhaust systems. My latest ran 9.50s out at Bithlo here in Central Florida.

Answers:
1. It worked great. I would do it again. And again. :)
2. I use tri-mix. 90/7.5/2.5 He/Ar/CO2
3. .024 ER308L
4. Tips: I MIG weld SS exhaust when I build stuff with slip fits or a big gap due to one reason or another. I use a stitch-weld technique as if I am welding sheet metal. With this method, you'll want lots of heat.

Once you get the right gas, wire, and set up, it's really no more difficult than welding ordinary steel sheet metal.

jp

[vancouver67]

Thanks for the info. So when you say stitching, you mean tacking every inch or so around the tube and slowly filling in the gaps till completely welded.

What amp mig are you using and what amp setting?

[parsonsj]

I've got a Lincoln Weld Pak 155 (an old 220V machine). I use the higher heat settings (mostly D -- the next to highest setting) and a wire feed of 7-8.

As far as technique goes, go here (http://www.mig-welding.co.uk/thin-metal.htm) and look for the video about halfway down the page.

jp