High frequency arc starter

[acooper]

I was wondering if any of you guys have any advice to offer. I have a HF251 and it works great, however today when I took it up to about 150 amps the arc started to get erratic kind of like the tungsten was contaminated, but it was not. I checked the spark gap on the HF251 and they were in tolerance. I did notice the contactors were a little off center. I'm not sure that would cause the problem. Gas flow is 10-20 and I'm using 3/32 2% thoriated tungsten. Thanks in advance. Adam

[popspipes]

Check your cables, I had this happen with a bad ground connection. I regrounded the work and it fixed the problem..

[captkipp]

You could try 1/8" tungsten. Although I doubt that's your problem. What's the power source for starters? I as well, recently had issues with my HF251-D or so I thought. Turned out that wasn't it. Although it's possible they can go bad, there's not much inside them to go wrong. And they are pretty bullet proof.

I'd check what POPS suggested initially. Then take a look at your other connections. Ground clamps are notorious for causing arc issues.

[acooper]

I think you guys are right on with the ground causing the problem. I was welding yesterday with the same settings on the same material and positioned my ground in a different location. Seems to have fixed the problem. BTW the power source is a Trailblazer 302. Thanks for the advice guys I appreciate it.