tungsten questions for aluminum

2 questions on the 2% thoriated tungsten I am using for aluminum. I have a PM 205 and I am getting enough decent welds that I think I am on the right track but a few uncertainties still.

1. From time to time I will get my tungsten turning blue. Nice color but not sure what this is telling me. Is this blueing of the tungsten tip telling me something about temp or argon flow or something I should be aware off?

2. A very good welder that was over trying out my PM205 was used to using older style tig welders. Can't remember the tungsten he was used to using but he like to turn up the cleaning action to first ball up my tungsten tip and then set up the balance back to proper penatration. Seems to me I have read somewhere that with the new inverter type welders and 2% thoriated one would not bother with the balling up of the tip. However when I do this balling up technique I notice the tip seems to last longer with out all the spliting of the end into a multitude of smaller balls. With the configuration I am using should I just be grinding to a bluntish point and forget about the balling of the tip? I am using about 175 amps for main and pulsing at about 100 amps. Any help on these two issues would be appreciated..........thanks in advance.

Wayne

Turning blue? Are you water cooled? I assume at 175 amp, you are. Try increasing the gas post flow. 8 to 10 seconds.

Other things to watch would be gas flow rate and cup size; maybe #6 at 6 lpm.

I don't pre-ball the tungsten with the inverter, like I did with the Miller syncowave. Also, I found that 2% Lanthanated maintains a better point with the inverter - see WeldingTipsAndTrick.com.
E.g., 3/32 ground at 60 degree with 0.50" blunt point.

Good luck.

Thanks dlong......I turned the post flow down a little while back thinking I would save on argon gas as I am mostly practicing and learning to weld aluminum so who cares if the welds crack or fail down the road as most of what I am doing is going in the recycle bin anyways. Figured I would turn the post flow back up when I returned to a real project. Glad you mentioned this as I am sure that is what is going on with the color and also I may of forgot to turn up the post flow for the real stuff. I will turn it back to where it should be.
To answer your question.... no I do not have a water cooled torch but I would like one. Maybe on the wish list I guess.Also the 2% lanthanated is impossable to get here in Vancouver.Not sure why. One and a half percent is no problem but no one has 2 percent and cant get it as far as I can find...........wayne

I've seen a blue tungsten for myself once. I don't remember what I thought the reason for it occurring was but I was very intrigued.
I was going to make a thread asking this question but I saw this thread and figured this would do. What tungsten is 'best' for AC aluminum? I have zirconiated, which is what I use on AC transformer machines, but I haven't tried it yet. I have tried thoriated and it seems to work ok. Although, the tungstens tip ends up looking a bit odd, but I am likely putting too many amps into a 1/16ths tungsten, around 110.

Sometimes I have read bits about ceriated being better, and sometimes I have read bits about 2% lanthanated being better.

blue tungsten is oxidation due to inadequate post flow. kick up the post flow a little. by the way, I stepped up to a 5/32 2% thoriated and was fially able to weld my guitarist's ladder jack back tgether. corner joint 1/4 architectural angle. w/ no preheat. I love this freaking machine.

Nanaf,
110 A is way too much especially in an inverter on this size electrode.