AC balance & cleaning

[broberts5]

I think I have lost some of the range on the balance and cleaning on my 250 EX.
It used to adjust to a very high pitch. Now, once I get to 30% cleaning and 200 on balance
I do not notice any change in pitch, if I continue to adjust it. Ant tips on how to verify this?
Thanks

[performance]

I think I have lost some of the range on the balance and cleaning on my 250 EX.
It used to adjust to a very high pitch. Now, once I get to 30% cleaning and 200 on balance
I do not notice any change in pitch, if I continue to adjust it. Ant tips on how to verify this?
Thanks

Balance doesn't affect pitch. Frequency does.

[broberts5]

Thanks. My bad. My real problem is that my tungsten is splitting. Doesn't matter much what amps. That's why I thought it might be frequency or cleaning. Any thoughts?

[performance]

Too much cleaning can cause issues. It's going to depend upon the tungsten. What type are you using? Red can split occasionally with too high of cleaning. It can be caused by low quality tungsten as well.

[broberts5]

I'm using 3/32, 2% thoriated, lanthanated, ceriated. Have used them all. It used to keep a nice point. Now it won't. My settings are: frequency-200, cleaning 20-30%.

[broberts5]

...even if I turn frequency all the way to 250 and cleaning to 10% it won't keep a point.

[performance]

200 and 250 hz frequency? Why would you want that? 100-150 hz is sufficient for 99.5% of all welding. It's likely you are putting too much stress on the tungsten running at that extreme. You could be putting too much heat too for its size.

[broberts5]

Thanks. I'll test that out. I guess I got greedy! I like a narrow bead with very little etching.

[broberts5]

I ran some beads with the freq set at 100 then 150. That gives me a very wide etching. It seems that I've lost the perceived advantage of the inverter. I do a lot of cosmetic aluminum for show cars. Things like al radiators. It's an advantage to minimize the etching. 100-150 freq and 30% cleaning don't do it. HELP!

[performance]

Drop it to 20%. But etching is a result of AC+ and TIME. If you are getting too much etching at a reasonable frequency (twice that of a transformer at least), you are going too slow, and/ or not using enough amps.

It can also be from too much standoff and torch angle. Do you have a penny's or quarter's thickness under the tungsten?

[broberts5]

I remember on my Lincoln tig355, an early square wave machine from late 1990s, I could set to 68% electrode negative. I was under the impression with the inverter I could nearly eliminate the etching with the capabilities of the freq and cleaning. I do think something has changed on my EX 250. It used to keep its point and provide narrow etching.

[performance]

I think it'd be easier if you could give us some parameters so we can weed out multiple possibilities.
What metal thickness/type?
Tungsten thickness
Gas type?
Flow rate?
Maximum amps?
Filler thickness?
etc.

[broberts5]

I generally have a 1/8 stand off with the cup tilted about 15 degrees. I should mention I have been tig welding all since 1978, so my basics are good.

[performance]

Things change a good bit with an inverter though. If you can help us out with a clearer picture, that will give us something to go on.

[broberts5]

Ok. Let's see. 3/16 al sheet. 150-160 amps. 3/32 tungsten. LPH-10. Pure argon. 3/32 electrode. 4043.

[performance]

tungsten type? Point?

150-160 amps can be at the top of the range for 3/32 (where you'll see more instances of splitting) depending upon the frequency and balance settings of the AC.
I'd bump it up to 180 amps for max pedal amps...even right at 200. Minimum recommended amps for 3/16" aluminum is typically 180 amps ( 1 amp per thousandth) or slightly above. It does sound as if you may be running a little cool...thereby going too slow.

[broberts5]

Thanks Mark. I'll give that a try.

[performance]

Are you using pure tungsten?

[broberts5]

Absolutely not. I am variously using 2% thoriated, 2% lanthanate and ceriated.