Spitting TIG weld makes me spittin' mad

[parsonsj]

I spent a frustrating couple of hours today trying to weld some tubes to threaded tube end adapters. 4130 tube, mild steel ends.

Piece of cake, right?

For some reason, the weld kept spitting at me. I spent considerable time cleaning the parts (since these welds will be very visible inside the engine compartment), only to ruin them. I checked the gas flow, the machine settings, re-cleaned the parts, etc. It behaved as if was contaminated by oil or something. I've never had that happen before. The weld was awful, full of holes and stuff bubbling throught the puddle.

I gave up, and went back to doing other things and welded lots of other stuff successfully. Then I used the same tungsten that spit at me before and it did it again on different parts. The only thing I can figure is that I have a contaminated tungsten. Anybody ever run into that before?



Any other thoughts?