Running out of MIG gas in the middle of a project is a problem most welders will eventually face.
Since many of us also have a tank of pure Argon on hand for other types of welding, would MIG welding with 100% Argon on mild steel allow you to finish your project without a trip to the gas supplier?
Or, is it possible to MIG weld with Argon alone, and get by with using 100% Argon welding gas for all your MIG and TIG work?