TIG for spotwelding?

[hugger6933]

While cleaning up a very little I ran across the tig torch setup for my 3n1 machine that does tig stick and plasma. I have only used the plasma since buying this machine in 2010. I have a huge 230 volt welder that I have used a very long time, but got to wondering about the use of tig in spot welding and welding in patches. The torch has a button on the torch so there is no foot pedal[ I think that is a compliant for working in a car] So my question is what Tugnsten and what rod do I need? Also will my 75% 25% Argon mix work I'd hate to lease a new bottle just to try this TIG thing out. Thanks