Anywho, material is 6061. The tube is 3/8" where it gets welded and the cap is 1/2" except for the center web. I used a heat gun to pre-heat the parts for about 10 minutes before welding. Only cleaning was a wipe down with denatured alcohol.
I used a 1/8" tungsten sharpened to a point with a flat ground on the end. I set the machine to independent polarity and used a 100%/70% ratio of EN/EP. Total amperage was 260 wich equated to 281 amps EN to 196 amps EP. You can see the result of this in the last pic. This is a shot of the tungsten after welding both parts. as you can see, it has very little wear after welding at such a high amperage. The other settings were as follows:
Tig start amps = 60 amps @ 60 ms.
Gas flow = 18 CFH
Straight Argon gas
1/16" 5356 filler
Hz = 120
Balance = 75