Mig welding stainless steel

[grannyknot]

I know how to mig weld carbon steels and my gas tank is 75% Argon 25% CO2 but I thought I would try my hand at welding together a new SS exhaust system for the Z. I have the ER308L stainless steel wire already, do I have to change the tank over to 98% Argon/2% CO2 or can I get by with the 75/25 ?

Thanks,

Chris

[winstonusmc]

 

Did this a couple monthes ago with 75% argon. Didn't turn out too bad.

[theczechone]

I would just make sure to do a couple of test pieces, but you shouldn't have any trouble. 

My plan is to tack the exhaust together on the car and then take it to my buddy at work to tig weld it all together. 

[grannyknot]

I forgot about this thread, I went ahead using the 75/25 with SS wire, completely different animal then welding carbon steel, took some playing around to keep from blowing holes.

 

[skirkland1980]

I never got the greatest results miging ss with 308 wire and 75/25. On the rear section of the exhaust I used the er70s wire and painted the welds with high temp silver spray paint.

[seattlejester]

My understanding was that not using tri-gas would end up with a weld joint that would eventually rust. If the piece isn't going to detriment from a little rust then no problem, but if you want the stainless property of rust resistance then tri-gas was the way to go.

 

Definitely different, I believe we had to play with the settings on the welder which we were using to do a couple mild pieces further down on the exhaust, different intensity and speed needed.