I was thinking of buying a TIG welder for the shop. I have mig welded for years (I know, a monkey can mig weld) but I wanna try my hand at TIG welding. I would buy an AC/DC machine so I can do aluminum. My question is, do I pay for some classes or just invest in lots of rod and just practice practice? I know the schools will teach me about metalurgy and the like but do I need that? Right now we weld mostly exhaust and general fabrication for everything from lawn mower decks to pig roasters. I just know if I can "lay a nice stack of dimes" I could expand to more "fun" projects. What do ya think?