I have a CIG (BOC) 3 in one. The stick and MIG work just fine. I can weld aluminium with the MIG but only down to 3mm. The welder never came with a TIG hand piece and is a DC machine. I wonder whether it is worth buying a TIG hand piece to weld thinner aluminium. I really aren't keen to buy another gas cylinder as I know Hellium is recommended for a DC machine. Anyone tried TIG welding thin, say 1.6 to 2 mm, aluminium with a DC machine and argon gas?