[Polobbie]

Hello,

Jody describes mig welding with stainless to be a bit more difficult than using standard 70S-6 wire. I am curious what is different about it specifically. I have been welding mild steel with stainless wire, and it does seem harder to get a good penetrating and consistent looking bead, but I'm not sure if that is what Jody was referring to and what I can do to improve things.

Thanks,

[Poland308]

Are you changing gas when you go from carbon to SS ?

[Polobbie]

Nope, I am using 75/25 as I normally so with carbon wire. I am welding carbon steel components using 308 stainless wire.

[thatoneguy]

Hmmm... Ive never tried welding carbon steel with SS wire. Then again I haven't MIG welded SS very much at all. Have you done a bend test or cut and etched your welds at all? How does the strength hold up compared to regular 70S6 wire???

[Otto Nobedder]

Stainless wire really likes a tri-mix gas, like 90% He, 7.5%, 2.5% CO2, but it can be welded with 75/25. You have to run it hotter, and accept that the weld surface will be grey.

Also, welding carbon steel with stainless wire is usually done with 309, not 308.

309 is an alloy that is designed for the dissimilarities between metals that welding carbon with stainless causes.

Steve S