TIG question (arc problems)

[Sodo]

Was trying to weld some SS, 1/16" thick with the MultiMatic200 (with Miller TIG kit). Had an awful time getting an arc started. Sometimes it would just make a conical halo around the sharp cone-tip of the tungsten. And when I did get a real arc going, the arc seemed hotter than the 'settings' was difficult to control. Ground clamp was set directly to the work, and was clean I think. Never got anywhere. Any ideas?

 

[LD1]

How are you grinding the tungsten?
What was the amperage?
How far away from the part were?
What machine and what all settings do you have available to adjust?

 

[Sodo]

Tungsten ground (parallel) on a beltsander. Previously when all was working I was using a flapper disc. That's the only change I can think of.

I don't recall the amps, because the machine has a 1/16" (thickness) setting. It does display the amps for that setting but I don't remember. Will try again and pay attn. Not sure I can say how far away, was trying anything to get the arc started but generally from 0 to 1/16" away. Basically it acted like it was trying to arc anywhere OTHER than at the point.

 

[LD1]

Sounds like a ground issue. I know you said it was clean/tight, but if I am picturing what you are describing correctly, it is exactly what happens when I forget to clamp the ground on.

 

[Shield Arc]

I'll bet it's the way you are sharpening the tungsten. Use a drill motor on a dedicated grinding wheel. Don't use the grinding wheel for anything but tungsten.

 

[Gary Fowler]

If your ground is proper, it could be a shielding gas problem. Is it a new bottle? It may be contaminated. IF you have used the gas bottle previously with good results, check the fittings on the torch all the way from torch to bottle. A loose coupling will suck air inside the hose and mess with your arc and weld.

 

[Sodo]

Hmmmmm. First welds offa fresh filled bottle. The valve was shrink-wrapped with the gas company's wrap.

I use these "CPC" gas fittings, always purge the short line off the regulator and hook them up with gas flowing. The other connector to the welder has a shutoff, it seals when disconnected and holds the gas in the line.

 

[C4Ranch]

Power source? Are you using generator?

 

[Sodo]

Not this time, its house current.

 

[C4Ranch]

Not this time, its house current.

Interesting... I got same genny as u and was stick welding with it yesterday on my Lincoln 210mp and it worked fine but arc behaved a little different...

My money's on post 5. Dedicated wheel...possible contamination if not..