I just swapped out a bottle of Argon from a new supplier and I think I may have a bad bottle.

I've gotten a bad bottle once before in the past that made welding aluminum next to impossible. Contaminating the puddle, etc.

This time around, aluminum welds perfect, however I'm getting very dull stainless welds.
My go to setup is a #8 gas lens on a WP20 w/Thoriated 3/32" tungsten @ 17 CFH. This has always produced great results for many years.
I've tried bumping the gas up to 20-25-30 CFH with extended post flow and even added some pre-flow.

Bevels and pipe are clean from the belt sander. The puddle doesn't bubble up any crap - the welds just finish up dull.

Has anyone had a similar situation? In my experience, bad bottles usually can be easily identified welding aluminum...

 

Sounds like a bad bottle.

 

Are you positive you're actually getting the flow you expect?

 

Yes, 25 CFH is screaming out of the gas nozzle.

This was also a trans-fill. I'm thinking a bad bottle, but it baffles my mind that AU welds perfectly.

 

Welding gold? Baller

 

Whoops, you know what I mean: AL .

 

I've had my local supplier give me a mixed bottle instead of pure argon and I didn't pay attention till I got to the shop and tried to weld with it. Now I check the label every time and hope that it's not just bad gas or mislabeled.

 

odd that it welds AL fine but not stainless, i got a bad bottle once and it would not do AL at all really, but i guess it could be in what mix you truly have. The bad bottle i had was marked only Argon but it was for sure bad because as soon as we changed it out it went back to welding fine making no changes to the welder at all.