buildup on Tungsten

[jeff408]

I have an older P&H HF tig welder and while trying to weld aluminum I get a buildup on the Tungsten. My set up is pure Argon set at 17 cfm and pure Tungsten. Any ideas why I get the buildup? It seems to add up pretty quick so I go grind it off with a fine stone and repeat.
Thanks, Jeff

[weldinglifer]

What size tungsten? how many amps? what position?I assume you are using ACHF. Argon flow seems low to me for Al.

[Jay O]

Maybe try to stop dipping your tungsten. Since the puddled is shiny, some have trouble telling how close they are to the puddle.

[jeff408]

Tungsten size is 3/32. The unit is a 300 amp, but I'm not sure what amp setting I'm on. Yea its on AC with HF. I try to keep the position straight up an down. I know sometimes I'll dip it on accident, but it seems like if I can keep some distance I still get the buildup. Next time I'll try turning up the Argon flow.

[papabear]

Does the machine have an A/C balance control? If so, where do you have it set?
Are you cleaning the alum. thoroughly before welding?

[forhire]

Is it a build up of contamination or simply the normal balling of the tungsten?

When I dip into aluminum it draws up into a nasty large ball. Not going to fix that with a stone. I normally snap off my tungsten just above the ball and re-ball it before continuing. I might be kind of old school.

[zapster]

Post a pic and we will take it from there..
No use guessing...

...zap!

[jeff408]

I dont think it has a AC balance control. I brush off the alu w/ SS brush and wipe with acetone.

Is it a build up of contamination or simply the normal balling of the tungsten? Not sure but I'm guessing its alu build up. It could be that I'm just getting the tungsten too close to the puddle.

next time I try welding I'll take a pic and try posting.

Thanks everyone for the help.