I did that a couple of months ago. I used my gms 400 on lift tig. I don't have a pedal for it either.
I had a cheap not so flexible wp 9 torch with a 1/16 ceriated tungsten sharp.
I used pure argon at 15 CFH with a #5 cup.
I was around 60 to 80 amps. I don't remember exactly though. I just know it takes A LOT of heat to get it to work. I couldn't imagine trying to tig even 1/8'' copper yet alone anything thicker.