"HA HA! I'm sure...Alaska is turning out to be one of the strangest places to live because we're the last state to get any kind of technology!"
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Our area may be a welding backwater also. Although Fresno, Calif., has close to a half million residents, the largest welding supplier here still recommends pure tungsten electrodes for GTAW welding of aluminum. If one wants to buy any kinds of tungsten electrodes besides pure and thoriated ones, they have to be special ordered.
Continuing with my own trial-and-error search for the best type of electrodes I can use for aluminum, I've found that my zirconiated ones have the most directional stability with my Thermal Arc inverter. That is, the arc consistently comes straight off the tip and I can point it at the root of a fillet. I've been trying thoriated and ceriated ones but, after a few minutes of welding, these produce arcs that come off the side at an angle. My zirconiated electrodes, however, do not withstand the amperage as well as thoriated and ceriated ones. Yesterday, for example, I was welding 1/8" stock at 125 to 150 amps AC (80% EN, 150 cycles/sec.). My 3/32" zirconiated electrode's tip gradually rounded up until it became a ball. A previous trial with a 3/32" thoriated one resulted in an angulated arc from the side, even though the tip remained quite sharp. I'm waiting for an order of 3/32", 1.5% lanthanated electrodes to arrive so that I can experiment with that type. As Lawrence mentioned in a previous message, some manufacturers produce better electrodes than others. He's found that some brands are superior to others. Buying all these electrodes to determine which is best for aluminum, however, can result in quite an expense!
I've been welding w/ 1/8" 1.5% lanthanated at 130-185 amps, 80% EN, 130-150 Hz on 1/4" and 3/16" aluminum today. I must say, after getting the right set-up, this is the most remarkable AC arc I've ever seen! But it seems that the lanthanated tungstens do tend to wear out after a while. I've been sharpening it and blunting the tip so there is a .010" wide land on the end. Sometimes I've noticed the tungsten kinda spits, but it doesn't spit into the weld...more like a tiny explosion happens because I can see a tiny spark fly off to the side. Over time the tip erodes and needs to be re-ground.
I tried my 3/32" thoriated tungsten too, but that didn't seem to be putting out the heat I needed for the 1/4" aluminum.
I guess all of this is a huge revelation to me because the guy I worked for a while ago had a Thermal Arc 300 or something like that and only used pure tungsten on it. He had an older Miller machine that also used pure tungsten, and looking back on things, the Miller didn't burn up tungsten nearly as fast as the Thermal Arc. I don't believe he knows what his inverter is capable of doing, and he is passing on that incorrect knowledge to any employees he has. That's why I found it so frustrating when I couldn't do the same thing w/ my machine. Nothing against old guys, but some of them are just too set in their ways...and when they try to jump into some new technology they try to mix the new w/ the old to come up w/ something better, which actually hurts them economically.
Here you go friend. the first link is to a PDF file from Miller electric. I have printed and laminated the thing and posted it right next to my new power sources. Sometimes the Old Dogs just won't go by word of mouth. So print up this article by Mike Sammons of Miller electric and hand it to your friend. Even tho the article is from Miller the technology is the same as with your powersource.
http://www.millerwelds.com/pdf/Aluminations_Ad_Package.pdf
http://www.millerwelds.com/education/tech_articles/articles30.php