Trying to weld pieces of 1/16"x1/2"x1/2" angle. I am having problems getting a stable arc.

I have no issues with high frequency start as it well initiate an arc with ease. It seems as though, when running low amperage the arc will begin to pop and crack.
They best way i can describe it is sputtering. I hqve noticed it will begin to sputter and pop right as the weld pool forms or right before.

While it's sputtering, i can hear the high frequency buzzing coming from the machine. Similar to the sound made when first initiating a spark.

If anyone can help i would greatley appreciate it.

Setup details.

Powertig 250ex

Cleaned aluminum with stainless brush and acetone.
I've tried adjusting gas flow from as little as 8cfh to 20cfh
Tried a watercooled 20 torch and an air cooled 9 series. Same problem with both.
Tried both the foot pedal and the torch mounted switch. Same problems.
Lanthinated tungsten. Sizes .040 and 1/16". Same problem with both.
Using gas lenses with a size 4 and 5 cup. Problem still present with each.
20-35% balance. Makes no difference in regards to sputtering.
I tried running the frequency from 60Hz all the way up to 200Hz. No change in problem.
Pre flow was tried at .5 all the way up to 2 seconds. No change in problem.
Post flow has been tried at 2 seconds all the way to 5 seconds. Problem still exist.
When using foot pedal, up slope, down slope, start amps, end amps each turned all the way down.

Ive also tried using varying pulse settings with no change in the issue I'm experiencing.

For those of you who are more experienced than myself, is it me or the machine? Anything i can try to look at on the machine to verify no problems exist?


Thanks in advanced foe any help.