Aluminum Contamination

[zx1200r]

Please look at the pictures in the link below. I'm welding 1/4" aluminum with 1/8" 2% Thoriated on AC. The welds seem to get contaminated with the 2% but look cleaner with the pure. Is the tourch suppose to look like photo 1 or is something wrong. Is there a way to tell if the gas or filler rod is contaminated?

pics of welds

[ROCK]

ZX1200R.............QUESTION........WHAT DID YOU CLEAN THAT WITH PRIOR TO TIGING...........TRY A STAINLESS STEEL BRUSH AND SOME ACETONE AND SEE IF THAT HELPS................ROCK
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[zx1200r]

I have a stainless brush that i use for aluminum only. I also used a propane torch to heat the aluminum and burn away the moister.

[ascwldr24]

Aluminum contamination

My question why use 2% Thoriated on aluminum? Use pure it will sure weld better. As for gas contamination What gas are u using if you are using an inert gas like argon with the proper flow rate you should have no problem. Also make sure you are using the proper torch angle to prevent contaminated air from being sucked into the weld.

hope this helps ya.

[chub380]

Pure would not work as well on the machine that he is using. I tried some lanthanated today and it worked very well, allthough the 2%thoriated works well for alum too with the Dynasty. Have you had any better luck lately with your alum problems? Chub

[ASKANDY]

Stay away from pure tungsten with the Dynasty. If you are looking for a better tungsten, try the Ceriated or Lanthanated. Make sure your balance isn't set too high. 75 would be a good starting spot. You may also want to switch to a 5356 filler. I noticed some of the same things once in awhile with 4043 filler. Your cup does look quite contaminated which happens when your balance is set too high and not cleaning the alum well.
We are assuming you know the base metal alloy and if it is a casting or what...
For the joints in the pics, my settings would be:

Balance, 73-78
Frequency, 95-140
Filler, 5356
Tungsten, Ceriated 3/32
100% Argon gas

Hope this helps.

Andy

[zx1200r]

Either electrode, pure or 2%, works well. The 2% just seems to focus the arc giving more control.
When I first start the weld it leaves a black spot.

[ASKANDY]

Sometimes that discoloration at the start is normal (a little brown at the edges). If it's eral bad or it gets worse, then you probably have a gas purity problem where as the bottle wasn't purged properly at the fill plant.
I was at Hendrick last month and they had a whole batch of bad gas. All the Dynastys were running terrible. We had to get a bottle off a machine that wasn't used much from a previous batch and all worked fine.

A-