Bad musicians blaming their instruments?

I'm not a teacher but I was a TIG student so I'll offer my view. Black and crusty sounds like the puddle made contact with the tungsten. How the assistant got it to work (assuming no electrode re-grind) is beyond me. IMO, the important thing here is that you are in the practice stage and these are the things you WILL overcome whether or not you get all the mysteries solved. Don't give up. These are the things we all go through. Maybe soon enough you will be on the list of "The Five Best Welders in the World"!!! I want to be clear that I do not intend to appear a smart as* using the word "mysteries". Welding can be one of the most intriguing things in life (science) and to me borders on the supernatural. ;^)

The next step would be to swap the TIG torch, on the Lincoln, for another one. It sounds like a leaking gas line that is sucking in air somewhere along the way.

Whether or not it leaks when somebody else uses it may just have to do with how they are holding the torch.

Check all the conections on the torch for leaks.

BTW saying what amperage you are using is kind of pointless if you don't say what you are welding or how thick it is.

I can assume from your statements that you are welding aluminum, and I suspect it is 16 ga, and you are making inside fillet welds.

If that is the case then 125 amps on the Millers is a bit high. The lincoln would be a bit low. Different machines can have different settings, but I have found that Miller usually is the most accurate on amperage.

16ga = 1/16" = 0.062" @1 amp per 0.001" = 62 amps.

• 30% for an inside fillet weld = ~ 85 amps.

You should be able to dial the machine down to that amperage and get a weld. If you can't get it to weld at that amperage, then your tungsten IS TOO DAMN FAR AWAY FROM THE METAL!!!!.

The 2 most common errors in aluminum TIG:

1. Your tungsten is too far away from the metal.
2. Your amperage is too high.

One thing that I noticed: when I (bad weldor) try to weld aluminium, I start to try to run the bead before the AC has cleaned the puddle (that may not be whats happening, but that's how I think of it) Result is a very dirty weld, lots of soot, etc. Some one else comes along, uses the machine exactly the same way, and by waiting a bit longer, or by applying heat in a slightly different way, they have an excellent weld. Now I use less heat than before, wait longer, get a puddle and let it sit for a few seconds before I start to add material and run the bead, and things work out better. Maybe something like this is what's happening to you?

Brian

He did say what he was welding:

"This is all on 6061 1/8" aluminum with 4340 3/32" filler, and a 3/32" zirconiated tungsten. "

and I was thinking his current on the Lincoln was too low and that he's probably using the wrong type of tungsten but I'm just starting to play around with TIG myself so I'm basing it on what the experts (You!) have said on here before. :-)

Best Regards, Keith Marshall snipped-for-privacy@progressivelogic.com

"I'm not grown up enough to be so old!"

You are correct. I missed that. That's what I get for doing usenet late at night.

Oh well.

1/8" = 0.125" @1 amp per0.001" = 125 amps for a flat butt weld or + 30% 41 amps = 166 amps for a inside Fillet.

You can connect an ammeter to the ground cable to directly read the amps the machine is actually puting out.

The current on the Lincoln seems too low to me when I'm doing it, yet it forms a puddle and melts the work just fine... I mentioned it because it seemed like it might be important to know in determining if the machine is just plain fubared or not. The current on the Miller is exactly what the little welding card I have from Miller says it should be... it also matches suggestions made to me by Ernie in previous posts. Same goes with the zirconiated tungstens... I usually consider any advice that comes out of Ernie to be worth its weight in gold, and so when he suggested long ago to try the zirconiated tungstens instead of the pure tungstens I was using for AC work I gave it a shot and haven't looked back since. They're terrific. They hold their shape better and survive the heat more readily than the pure ones do, and the quality of my welds has improved since I started using them. They're harder to come by in my area (I'm forced to mail order them), but they've been an excellent investment and the increased life I see with them makes them a better value.

Bryan

Ernie also likes the Lanthanated tungstens. I bought a bunch of these on ebay for about 1/10 of what my local guy wanted.

weight in gold, >and so when he suggested long ago to try the zirconiated tungstens instead of the pure tungstens I was using for AC work I gave it a shot and haven't looked back since.

I ordered mine from (I think) welding-direct.com, I was going to go the eBay route but every single time I have ever tried to buy anything through there I've gotten pretty badly burned so I avoided it. As I recall welding-direct.com has a really annoying minimum order amount, but it wasn't so bad as I was ordering about four or five packs of tungstens.

You should give the zircon ones a try... I have the white ones, I don't recall what the zircon percentage is, but that's the color. For welding with AC, the zircon ones were just fantastic, especially if you have an air cooled torch. They survive the heat so much better and keep a nice tight ball on the end of the electrode instead of turning into a bigger and bigger blob.

Bryan

So which is better? Lanthanated or Zirconium?

Lanthanated is equally good on DC or AC, but Zirconium can take even higher heats on AC.

Never use Zirconium on DC, it will disintegrate.

The only tungstens I buy for my shop are Lanthanated, and Zirconium.

Is it possible that the switch contacts are in rough shape and the others were pressing harder than you? If so, then you might not be getting gas flow while they were.

Ted

Thanks, Ernie.

J

What type of tig set-up are you using? Variable current such as a foot pedal? Scratch-start with a manual gas valve? Steel, ss, or alum?

Patrick MTS

Thermal Dynamics 250GTSW AC/DC inverter with HF.

Torch mounted slider gives variable current from zero to value set on the machine.

No!

Yes and others from pewter to high speed steel.

Ted