Stainless Mig Welding

[Troy]

Hey All,

I've ordered S.S. mufflers and I;m getting ready to order a S.S. exhaust system. Can I mig weld the system together? If so what do I need to use, gas and wire to do proper welding? Thanks for your expertise?

[chevynut]

https://forum.millerwelds.com/forum/welding-discussions/19184-welding-stainless-steel-exhaust-pipe

https://www.lincolnelectric.com/en-us/support/welding-solutions/Pages/compact-welders.aspx

[Troy]

Thanks Cnut, It sounds like it can be done, one thing I need to find out is what S.S. the mufflers are. The exhaust system is 409 stainless steel, so hopefully they match.

[chevynut]

Thanks Cnut, It sounds like it can be done, one thing I need to find out is what S.S. the mufflers are. The exhaust system is 409 stainless steel, so hopefully they match.

If they're magnetic they're 400 series (ferritic stainless). If a magnet doesn't stick to them, they're 300 series (austenitic stainless). I don't think there's a problem with wending 300 series to 400 series.

[Troy]

Yes I know this about the alloys, I was just saying the vendor I bought the mufflers from doesn't list the alloy. The only thing about my question regarding different alloys was because one of the articles you linked to said it was only for 300 series stainless. Thanks for the info though.

[Rick_L]

Part of the discussion in one of Cnut's links was about what welding gas to use.

This discussion adds a bit more. https://weldingweb.com/showthread.ph...-(16ga-409-SS)

So it looks like you're going to have to get a bottle of tri-gas if you want to do a rust free job. The link above suggests that if you use 75/25 (which is probably what you have for steel), you might as well use steel wire too. It's one thing to buy a 2 lb spool of wire, another to get set up with a new welding gas - for one job. Even if you can rent the bottle for a short time.