i plan to mig some stainless together this weekend for an exhaust need to know if anyone here has sucessfully done it with a mig using 75/25 argon/co2. any pics etc. i heard to use helium but i only have a single bottle and dont want to get helium if i can get by without.

 

c25 is for mild, use either trimix or straight argon

 

Trimix aka"gold gas" is rad as hell. You can run a real nice weld on stainless with the right gas and wire. good luck man

 

oh yeah tri mix is alot easier to weld with than straight argon... but you can use either..

 

DO NOT use 100% helium. The arc will wander so badly that you won't be able to get a good weld made.

 

anybody want to explain exactly what trimix is?

If I go down to my local Airgas will they know what it is?

 

Yes.

 

how thick of a piece of stainless steel can a 110v mig welder (lincoln sp135plus) mig with "trimix"...? dont mean to thread jack, i'm interested in the same thing. can it do exhaust/IC pipes?

 

tri mix is mostly helium with a little argon and a trace of co2

the more co2 you add the more corrosion resistance you loose with stainless. the SS exhaust welds i did on my car using c25 have evidence of rust even though its SS tubing and SS filler

 

just use argon, it'll be fine... also make sure you use the proper wire!