It is time to re do my loud assed exhaust system. When I originally ran the exhaust I was dimensionally challenged and used the only mufflers that would fit; 10" glass packs. The most pressing problem was I could only select from "steel" mufflers. My choices for mufflers greatly increases if I go SS, however. So my question is this. Can I teach myself to weld SS? What gas mixture would I need assuming 75/25 isn't good? Any tips or tricks to practice. Does the Miller "auto weld" feature work on SS as well? Is a different type wire needed? Can SS and carbon steel be mixed? Can SS be gas welded? Zillions of questions! TIA, Kent

you need stainless wire, tri mix gas ( mostly helium + argon + CO2 ) You CAN run it through the liner you have, but most pro's will have a separate liner for stainless, or a spool gun.

Yes you can combine mild steel and stainless exhaust components, you are still best off to use stainless wire when doing that

Yes, stainless can be gas welded, but if you are doing this under the car, I'd recommend against it unless you are extremely good at gas welding

No idea on the auto settings, never had a welder with them, but it should work fine as yuor settings for stainless aren't going to be a huge difference.

I loaned my cheap Century 110v MIG welder to a co-worker that used it to weld up a bunch of stainless sheets and tubes for some art project at his house, my bottle is the argon/CO2 mix and it worked for him.

He bought a roll of stainless wire for it and gave me the rest of the spool for loaning him the welder, no idea what grade, I think it is 308 or 309, I can look and report back if interested.

Basically yes to all your questions I would say...

Pay for shipping both ways and return what is not used and I'll send you spool I have once I get the info off of it to see if it'll work.

That's a deal! PM your contact info after you verify the type. Do you need anything for your build that I can reasonably provide as repayment?
And Scotty, thx as always for sharing your knowledge with us. Kent

Not that I would recommend it but I have welded stainless to both mild steel and stainless with a MIG set up with mild steel wire and standard argon/CO2 gas mix.
It was on an exhaust system and 3 years latter it was fine.
Stainless steel and mild steel expand and contract at different rates as they heat up and cool off. I expected the exhaust system and/or the welds would crack due to the expansion issues but that had not happened last I saw of it. The welds showed a little tarnishing but that was about all.

Jim

I've done it many times, I've also never had a failure. it will rust in the weld area.
It worked on the same settings as mild steel, it actually flowed a bit faster and it's relatively easy to get good looking welds.

I've also TIG welded it in SS, if new to TIG .060 and up SS is a good first time project. Tig set ups are expensive but entry level units are getting cheaper.

If anything stainless is easier to weld than mild steel due to the bad heat transfer coefficient of stainless. Easier to keep a good puddle and flow going... Use higher alloyed wire than the pipe/muffler and you should be fine.

308L, 2lb spool, maybe 1 pound left?

Welding Stainless is real easy with plenty of practice.
Most of the time you dont need any rod or filler wire.

Here’s a picture of a stone guard I made for one of my other cars in stainless. The UK 10 pence coin is just a little bigger than a US Quarter. These stainless welds are about 1mm in width and need no cleaning up afterwards.

Kent,
Let me know when you want to play with a TIG unit. Just bring the filler rods.
Cesar

Nice!

I'll pm you.


That would be cool but I need to do the work here, Ceasar.