Your gas supplier that you buy your tank from will give you the correct gas Doug. 75% Argon/25% CO2 is the most common all round gas and will give you the best results for short-circuit type of welding, which is what you will be doing on a restoration. .025” wire is the most common wire that you will use for your sheet metal welding and you will be able to ¼” together with but would be better off switching to .035” wire for any of the heavier jobs.
Not relevant to the sort of equipment that you are using but just in case your interested in adding to your knowledge base; 100% CO2 is used for globular transfer (mode is rarely used) and it will give you deeper penetration but creates a lot of spatter. The arc stabilizes as you add argon and is ideal for the short arc transfer mode. In industry where large clean spatter free welds are called for the mode of transfer is often spray mode. You can’t get a true spray mode when the CO2 concentrations are over about 20% and the most common gas’s used for the spray mode are 90% Argon/10% CO2 or 95% Argon/5% Co2. The spray mode requires rather large high-current industrial welding equipment so you will probably never see metal transfer in this mode.
Hope that
Denny Graham
Sandwich, IL
