gazim,
I just filled my cylinder the other day. The price of the mix was almost twice the price of straight CO2.
25/75-Argon/CO2 will give you less spatter, and the heavy Argon tends to freeze the weld puddle a little faster.
The Argon supposedly focuses the arc and gives deeper weld penetration. This is something you wouldn't want on thin body panels.
I spent all weekend building "half-doors" for my son using 18 gauge, welded to Toyota 20 gauge sheet-metal...I was nervous, but with .023 wire and the Blue Shield gas, the project worked out fine.
Stuart
