Tungsten problem

[Birchum]

I am having a problem with my tungsten. (2% thoriated)
It keeps developing several small burrs when welding.
they look like this:

\!!!!!!/

On the end of the tungsten.I am welding cast aluminum that is pretty thick so pure tungsten wont work. (Boils off)
What causes this and what can I do?
Thanks.

[ROCK]

BIRCHUM..........WELCOME ABOARD........What is your amperage range your at.........Perhaps the tungeston is to small for the amperage range your tig welding at........What is your gas flow maybe the tungeston is cracking and splitting because it is to hot..... Just a couple of things to consider..............Rock..........
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[Sean Brown]

Try using Lanthanated or Ceriated tungsten's instead. Also, going up in size as ROCK says is probably going to help, but I've always found that 2% fingers-out like that when using AC.

Pure will work also, but the heat carrying capability is lower than the other two options I mentioned.

Sean

[Birchum]

Thanks for the replies.
I am usually running at 150a or less. AC bal at 50%( most of the time)
My gas is set at 20cfh.
I've never used any other than pure or Thoriated.
**What kind of pros/cons are associated with the lanthanated and ceriated tungsten?**

[shadetreewelder]

Tungsten Problem

Birchum,

I have always had good success with Zirconated electrodes when welding aluminum. I was always taught the Thoria will contaminate aluminum welds and should not be used. Zirconated electrodes run similar to thoriated?

Are you running AC and is it a square wave machine? How large is your ball at the tungsten? During welding.

Good luck,
Ron

[weldteacher]

Here's my best suggestion for your problem; At 150 amps AC you need to use a 3/32" diameter Zirconiated tungsten. The 2% thoriated tungsten is not designed to be used on AC. It is best suited for DCSP use. The addition of zirconia raises the melting of the tungsten electrode and adds a stablizing effect to the arc. The use of 2% thoriated for AC is noted for splitting and grape balling. Use the zirconiated tungsten with the brown band and you will weld like a new man.

[mowjunk]

Bircham, I agree with Weldteacher and Shadetreewelder. I just started using the Zirconated tungsten. It will carry more current than the same diameter pure tungsten and it will also form a nice balled end similar to pure tungsten. I just finished repairing an aluminum boat using the 3/32 Zirconated tungsten. I ran as low as 60 amps to 130 amps on this project with no problems using a Syncrowave. Just my 2 cents....

[Birchum]

Thanks....I'll give the Zirconiated tungsten a try.

[HAWK]

What's the best tungsten for welding aluminum on an inverter machine like the Dynasty? Miller recommends ceriated and thoriated as a second choice because it is less expensive or so I gather from some of ROCK's posts. I am using 2% thoriated sharpened to a point and then blunting the end. I'm not having any problems, but have ordered some ceriated to try. Would zirconiated tungsten be a better choice for the inverter?

[weldteacher]

Hawk,
Here's the skinny on tungsten electrodes. Ceriated is a good general purpose electrode and 2% thoriated if great for DCSP welding as zirconiated tungsten is best for high current ACHF welding. The rules have changed a little when the "squarewave" and "inverter" type power supplies came off the drawing board. The output of the AC waveform (balance) can be changed to best suit the needs of the weldment. Hense, setting the balance to "max penitration" will push the AC current into a 68% DCSP/32% DCRP output forcing more heat into the work. With an Inverter type power supply the waveform can be even further adjusted to include the frequincy at which the AC current is supplied to the torch/work. The bottom line is the more the output is in DCSP(eletrode negitive)portion of the AC cycle the better it is to use a 2% thoriated tungsten. But, I tend to recommend useing a zirconiated tungsten for all ACHF jobs.

If you really want to test yourself on aluminum get a cylinder of helium, install a 2% thoriated tungsten, set the machine to DCSP, clean the work very, very well, preheat to part to 250 degrees F. and weld it the "old fashioned" way. If you get it right the depth of penitration is very deep!
P.S. take a patiance pill for this one.

[Bertram Chase]

Tungsten

Hey gents, let me throw my 2 cents in. I dont recommend Zirtung with an invertter on Alum. I do recommend Certung or Lanthtung. 2% Thortung will leave tungsten deposits in the weld at high amps. Found out hard way on X-ray. Now you can eliminate that with a setup I found on the Dynasty 200 Dx. Using 50-50 HeAr and 250htz,65 bal the end of the thortung will ball very slightly but leaves enuff of a point to effectivly use the full potential of the higher frequency.
I use it when I dont have any of the other tungsten. The concept will work on the older Syncs too but it will ball more due to the lower frequency output. This is my conclusion on all the experiments I have run. 100 or so for a week. Well theres my 2 cents.
Thanks guys.

[weldteacher]

Mr Chase,
What have you found offensive about Zirtung on aluminum with an Inverter? There is always something new to learn/teach.
Many thanks, Kevin

[Bertram Chase]

Zirtung

Actually with the Dynasty 200 dx a point is preferred. The Zirtung tends to ball. More so with increased amps. Just a personal thing I guess.

[ASKANDY]

If you keep your balance number up. The Zirconiated won't ball as much.(really no need to run balance under 70 unless you have some junk aluminum or it's oxidized bad enough) Also the Dynasty's hidden menu can adjust start currents to suit your tungsten preference. With the Dynasty's, the Lanthanated/Ceriated are usually the way to go.

Andy