[Ant428]

Anyone know what wpuld cause this ugly stuff in my weld. Tig on AC .....15cfh #8 cup. 3/32 tungten.

Looks worse on camera. Lol. Still it has some soot in it . My aluminum welds usually look good. These are ugly! Could it be pulling crap from the inside of the tubing?

[Oscar]

Unless your tungsten stickout past the cup is very short AND you're keeping a very short arc length, I'd say 15 CFH is too low. For a typical stickout and arc length, you need about 20 CFH.

[cj737]

Poor gas coverage and arc length are typically the two greatest causes, but you also need o insure the filler wire is cleaned, and what balance are you running? The pictures show some cleaning of the area during prep, but what about the interior (tubing) and the actual ends where it’s been cut or sheared? These are places where contaminants like to lurk...

[HREFabLLC]

Definitely clean the base metal and filler wire as best you can. Typically wire brush the base metal to remove the oxide layer. I'll take it a step further and wipe everything down with acetone. If you're still experiencing issues I would take a few passes with the AC balance set below 60 to provide some extra cleaning action.