Welding Tips and Tricks

I've taken and passed a 1,2,3g aluminum butt test with tig. 1/8" metal. I want to get my 4g as well, but Ive tried to practice and have no luck. I keep undercuting my face and can't punch through and penetrate the back.. Does anyone have any tips?
I've tried this on a dynasty 200 and a 210. I used around 140 amps, I had my balance at 67-70, which seems to work since all the aluminum I'm using is fairly clean. My frequency is at 130.

ClassyTaco1 wrote:I've taken and passed a 1,2,3g aluminum butt test with tig. 1/8" metal. I want to get my 4g as well, but Ive tried to practice and have no luck. I keep undercuting my face and can't punch through and penetrate the back.. Does anyone have any tips?

Pretty sure lots of experienced welders here can give you tips. I'd say help them help you by stating all the machine specifics.