Uh, do we have a difference of options here from two of the 'journeymen' on this forum?
Hotrod thinks CO2 with very mild small diameter wire is the trick. Bartamos seems to think CO2 is too hot for thin panels and think 75/25 would be a better fit for us, 'the unknowning'.
I have no pure CO2 bottle in the shop but that's just a money thing. I have used 75/25 on all my mig projects so far and don't remember the wire number but that's just another money thing.
I guess the old saying applies, "There's more than one way to skin a cat". I just have to find the right knife.

Six volt guy living in a twelve volt world