That looks horrible, I've seen dogs that can $#!T better than that!
Are you sure it's not anodized? Oscar asked that early in the thread, but you didn't respond. In fact he asked twice. You say it's a 2mm coupon, where did you get it from?
Also, your tungsten in the OP is contaminated, can you show what you're using to get these fugly welds? What type of filler? Have you tried to run a bead with no filler?
I've never seen such fugly looking tig beads, that's a first for me.
I would start with basics, turn all pulse off, 90 amps, 6 seconds of postflow...make sure you're on AC and that you have your torch plugged into the negative, ground in positive. You should have pure argon at about 12-15 CFH with a #6 cup (make sure your flowmeter shows CFH, if not adjust accordingly). Set balance at 30%, don't use filler, just run a bead on the aluminum. Something is terribly wrong, you need to isolate it. Tungsten should stick out about 3/8". Make sure there are no gas leaks, torch is assembled properly. You gotta be able to do better than that. Remember a lot of this rests on you, we can't ensure you're using 100% argon, we can't ensure your tungsten is properly sharpened, we can't ensure that your stickout is correct or your torch angle is correct, we can't even ensure that you're not using anodized material or that you're not using 7075, and we can't ensure there are no gas leaks. If you want to figure this out, get busy and start checking that stuff.
> All with 7.5 l/m
What is this? Is this inch/minute for wire feed or liter/minuite for your gas?
> AC/DC standard pulse
What does this mean, you need to be on AC for aluminum. Turn the pulse off.