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Frosty looking weld quality?

Posted: Fri Sep 23, 2011 6:59 am
by MeatHead
Hello fellow Tig Welders,

Can you please critique my weld and offer some advice? :D

I've been practicing A/C Tig welding on a 1/4" 6061 aluminum plate and my welds keep having this frosty quality. I turned the A/C Balance (cleaning) down to ~37% (almost all the way to the left) and it looks like marginally better penetration, but I want a shinier/cleaner stack-of-dimes look with better penetration. The arc starts consistently, but it doesn't seem to focus on one spot very well (frequency in the 100-120Hz range) and dances around until I start adding filler.

Machine: PowerTig 225LX
Torch: air cooled hand-held with switch, control in 4T position
Gas: 100% pure argon
cup: everlast #7 cup
Flow: 7L / min
Tungsten: 3/32 2% lanthanated (sharpened to point)
Filler Rod: 3/32 4043
Amps: (I forgot :P)
PreFlow: ~1-2s
PostFlow: ~8 seconds
Pulse: Off

Metal Prep: 80 grit belt sander on surface, followed by rigorous brushing with a steel brush (only used on aluminum). Then, it's cleansed with 100% cotton cloth dipped in acetone.

The bead on the left half-way pictured was done with balance higher in the ~10 o'clock position.
Image

Re: Frosty looking weld quality?

Posted: Fri Sep 23, 2011 9:44 am
by weldin mike 27
Hey there,

Make sure your wire brush is STAINLESS steel. Not normal steel. The normal steel brush will contaminate the Aluminium. Also try skipping the belt sander bit as cirtain belts/ discs can impergnate the AL with impurities, and just use the SS wire brush and cleaner.

Hope this helps.
Regards Mick

Re: Frosty looking weld quality?

Posted: Fri Sep 23, 2011 4:15 pm
by Davidep82
+1 for Mick, I agree.

Re: Frosty looking weld quality?

Posted: Sat Sep 24, 2011 6:41 am
by weldin mike 27
Hi David,

Thanks for the +1. I haven't actually done alot of Al welding (all steel) but I've got a pretty good grasp of the rules. And I like to be able to help people.

Kind Regards
Mick.

Re: Frosty looking weld quality?

Posted: Thu Nov 10, 2011 10:35 pm
by joseph.mowery
Do you clean your filler rod?

Re: Frosty looking weld quality?

Posted: Sun Nov 20, 2011 9:06 am
by eliotmay
I'm pretty new to aluminum myself but are you preheating? My arc will dance a lot at first if I don't preheat. Also remember they say you need at least one amp per 1/1000 th thickness, that's 250 amps if my math is correct