welding 6061 T3 schedule 40 anodized pipe?

[pszelwach]

There is a wealth of knowledge on this board but I haven't quite found the right topic. I would like to get into tig welding stainless steel and aluminum. The stainless (up to 3/8") doesn't seem to be an issue but what about anodized aluminum pipe (6061 T3 anodized) in sizes up to 2" and maybe some 6063 plate up to 1/4". Wall thickness on the pipe is .154" and I want to know what type of amperage I need so I can narrow down my welder choices. I have the opportunity to get a syncrowave 180 for price pretty close to the econotig/tigmate but I've been told that it's not enough machine for the job. Can you shed some light on this or is there a reference I can seek that outlines recommended amperage for a given thickness/type of material.

[chip hayden]

here's a very non-scientific answer.150 amps on .187x2 6061 will just start to melt a lap joint. once the aluminum is up to temperature it goes ok. i suspect you will have the "pedal to the metal" a lot to weld the pipe because you will constantly be changing your torch angle as you walk around the pipe. a 75/25 ar-he blend will help.