Pete - yes, basically what we call "argoshield light" which is 93/5/2 AR/CO2/O2, it works fine on thicker stuff but you have to go good and hot to get the penetration.
I've always used this gas, but I'll go to a"universal" mix next time i change the bottle - probably 15% CO2, 2% O2. Most of what I weld is in the 5-8mm range.
ttoks -For some reason this Miller set works nicer on dip transfer than any other machine I've used - maybe because on other machines I'll fine tune with wire speed, whereas on the inverter I adjust both WFS and voltage. It just seems so much easier to dial in to get minimal spatter and excellent sidewall wetting.
Somehow at work we use the same "light" gas for everything upto 10 ton lifting equipment, which is always tested by a notified body and passes ok, we've done it this way for the last 20 years, long before I was on the scene. It's only recently that I've realised this and got "heavy" gas in stock for structural work - 20% CO2, 2%O2, we have never used it before so it will be interesting to see what it welds like with in the same machines. If like you say, it spatters everywhere at 28-30V, I suspect the fabrication lads will complain bitterly
