alum. welding settings ...

[tdwinklr]

My 252 is set to 18 volts and 280 on wire speed to weld that kind of tubing.

that makes more sense. The chart on the machine shows 18.5 / 380, looks like a misprint.
Is your setting with .035 or .030 wire?

[Draco]

It's with .035 hard wire. If my normal settings seem too hot then I usually just trigger weld it. Hit the trigger, push back a puddle and stop. Hit the trigger same same. Works really well for short welds.

[Texas Grown]

that makes more sense. The chart on the machine shows 18.5 / 380, looks like a misprint.

Is your setting with .035 or .030 wire?

Checked mine last night and my chart said 520.

Wire speed is controlled by my lead in the handle. I set temp and Wire speed to type of weld (up, down, flat butt, ect). Don't hold nozzle to close. And set Gass at 35-45.

The fish are biting, and there's hogs to be kill-t. Gotta go!

[Bluesman]

TIG has the advantage of preheating the material in advance of the weld. So, more weld penetration is more likely to take place.
When using wire, the guys at work will often preheat the joint with a torch to make the aluminum more receptive for welding. They get less sputter and the speed of the weld is faster. With better penetration.
Most of the guys attended vocational schools when those schools existed.
You might try beeline the ends of the parts with a grinder. This allows for a better visual joint, more penetration, and a flatter weld. Hopefully no grinding.