[TwentyFourSeven]

I see videos of tungsten type testing and sharpening. They all seem to get a nice looking ball on the tip but for some reason I can not get a nice ball on the tip to stay. Mine always end up looking like this and I can not figure out why. I am running #7 gas lense. 3/32" Thoriated. 140 Amps on ac welding 1/8" Aluminum. I weld nuch better when the tip is sharpened and it first forms a nice small ball but quickly turns to this mess. Same thing happens when I switch to 2% Lanthanated. My gas is between 17-20 at all times but doesnt seem to make any difference either.



http://i125.photobucket.com/albums/p51/ ... 88f9c3.jpg

[dsmabe]

What machine/settings are you using? I end up fighting the same problem sometimes, i will normally regrind then get a piece of scrap, set the machine to around 125 amp with cleaning action turned all the way up. Light a arc, watch for the tip to ball, extinguish the arc, set the machine amps/balance and it is normally good for a while.

[Otto Nobedder]

My first guess is you have too much "EP", or cleaning action. It looks a bit like the tungsten got so overheated it "boiled" and blew up. This could be either an incorrect setting (some welders, the Chinese ones in particular, can have the balance control labeled backward from what we're accustomed to), or a machine problem of the setting is correct.

The other possibility is a bad batch of tungsten (it happens), but that's unlikely as you've said you've switched alloys.

Try it with a pure tungsten and see if you can get it to cooperate. The behavior of a pure tungsten will tell you if your balance control is working correctly, or not at all.

Steve S

[TRACKRANGER]

Good tips above.
Also, can you make sure that all that shielding gas is actually getting to the cup. That there are no leaks anywhere.

[TwentyFourSeven]

Useing the Lincoln precision tig 225. AC turned all the way on penetration but even when its half way or on full cleaning it does it when I weld with high amps like 140.
Lower amps welding 1/16" stuff on 70 amps is fine with the 1/16" Tungsten. The higher amps just seems to screw up the tip. Should I try 1/8" Tungsten?

[WTFH]

I agree with otto try a pure if you have it. I would also try with a 3/32 2% lan tungsten, just bust the end off, don't grind it set the balance to DCEN/penetration and see what happens at 140 amps. Maybe you have some crap on your grinding wheels also if it is contaminated you might not be getting all of the contamination off while grinding. Usually when grinding off contamination the point is ground clean but there is still some contamination up the taper. Did the arc make a weird noise when it happened or tungsten fly off the end?

[Bill Beauregard]

Is it possible the screen in your gas lens is fouled? Mine only does that if the EN is at 60% or lower, or the heat is very high.

[Braehill]

24/7,
I'd try the 1/8 if I we're you, if it doesn't do this with all other setting the same, then I would think that the tungsten is overheating. I usually find this happening to me when I push the amperage limits on my tungsten. I use a transformer welder with no balance adjustments so this shows up more often than it should with an inverter. Just remember, you can always grind your tungsten smaller but you can't grind it bigger.

Len

[TwentyFourSeven]

I think your right. I think I'm just running past the limits of the 3/32" tungsten. I will try 1/8". Even though I am following Lincolns guide lines for amps, gas and tungsten I am doing production welding. Not giving much time of the foot peddle all day long. My machine after 2 1/2 hrs of running starts shutting down in to cool down mode also. Once it starts doing that it then does it every 40 minutes for the rest of the day. I am not sure what the duty cycle is at 140 amps but I know I am way over. I have a jig set up and I just keep dropping fresh metal in it as soon as I'm done all day long. I have a fan behind the machine and I am in a small garage in Florida where it's often 98* in the shop.