[nero]

Hi guys,
I'm going to give a try to MIG weld some 2mm 304 stainless steel.
I've read somewhere that for single-pass the classical 75%/25% Ar-Co2 mixture it's acceptable, so I think I will start with that one (which I already have).
But what about the purging gas for the backside? Can I use pure Argon as in TIG welding, or the purging gas should be the same of the shielding gas?
I suppose that the amperage setting on the welding machine should be a little bit lower compared to the one used for mild steel, is it correct?
What about gas flow? Do you think 6-8lt/min will be a good starting point?

Thank you very much,
massimo

[anthonyfawley]

I keep my gas about 13- 15 for just about everything, i also use the purging gas a 75 25 mix. works for me. Most of what i weld though is sch. 40 304 or 316 pipe (When welding S.S.). I will only turn the gas up for wind or if i have to stick the tungston out far to reach a tough spot. If its been a while on the thinner stuff ill try hotter and work my way down on a scrap piece 1st. Hope i helped a little.

[nero]

Thank you anthony.

[RIS]

When I weld solidwire stainless I always use 98/2% gas.

And I havent tried to purge with an other gas than the one that I weld with, and I would bet that it is the safest.