TIG question (arc problems)

[Sodo]

Ground clamped was directly to the shiny SS part, should be good, but I will clean it further to eliminate that. The beltsander had sanded some steel recently & since the misbehavior is at the tungsten I'm thinking its' got steel contamination. The initial arc is OK for about one second, then it does the halo thing. So I suspect the steel bits on the surface are causing trouble as soon as the tungsten gets hotter than steel's melting temp. That's probably it. If not it was a good theory.

Will try the flapper disc that has done nothing but tungsten. I've learned why TIG welders have dedicated TIG grinding wheels...

#1) of course, the cleanliness.

but nobody ever says #2......

#2) you spend a LOT of time re-grinding the tungsten. It needs to be quick and easy. Even picking up the angle grinder, positioning it, then waiting for it to spin-down, and not setting it down where it will get contaminated, takes a lot of time when you have to do it so many times for one stinkin' little weld job.

 

[Shield Arc]

I'd get rid of that regulator, and buy a flow meter for Tig welding.
HTP Argon CO2 MIG TIG Flow Meter Regulator Welding Weld | eBay

 

[Sodo]

This regulator is the one supplied with the Miller TIG kit. It worked fine before (apparently). Although I was a little surprised how fast I used up a 50CF bottle.

What difference would you expect betw. the two?

 

[Shield Arc]

What difference would you expect betw. the two?

Accuracy!
I had two shifts of welders splicing these 10-feet in diameter pipe just down river of the Bonneville dam. Running 1/16" dual shield. 100 % xray. I bought all regulators, the welders refused to use them, they wanted flow meters.

 

[BukitCase]

"I was a little surprised how fast I used up a 50CF bottle" - if your settings are right, that bottle would only last 2 - 2-1/2 hours - if it was 'WAY shorter than that, you might have been looking at the RED setting scale (LPM) - although I doubt you would make that mistake, it might also explain the crappy arc

You ARE using straight Argon, right??? Steve

Also, on tungsten grinding SA forgot to warn you - you don't wanna run the drill more than its SLOWEST speed using the drill/grinder method, or you'll put a SPIRAL/CONCENTRIC pattern on the tungsten - that can REALLY mess with your mind...

 

[Sodo]

I twirls the rod in my fingers. I get the point I want grinding it cross-ways on the angle grinder using a flapper disc. Then the last twirl is a slow 'polish' (possibly shinier than anything Steve has ever seen) and the very fine scratches are axial to the tip.

I think I figured out the "arc halo" problem. Going back to using my "ONLY TUNGSTEN" grinding disc did not solve the problem. It may help but it wasn't the problem.

When I first press the pedal, the gas flows forcefully, then it steadies at a lesser rate. So it's like the gas flow is too much at first, like it's doing a 'purge'. If I start the arc immediately after pressing the pedal, it has that Halo problem. If I wait for just about 1 second for the gas to slow down,
then do my :thumbsup: "LIFT arc" :thumbsup:
then the arc starts normally. What a relief. Not sure how that came up, maybe I was just welding faster!

Heres a stainless motorcycle protection bar 'repaired'. Man this TIG is fun stuff!

 

[Shield Arc]

Your welder doesn't have pre, and post flow?

 

[Sodo]

Well I guess it does!

I was probably just doing my :thumbsup: "LIFT arc" :thumbsup: too soon. Going off all half-cocked like some young feller! After I release the pedal the gas flows for a few seconds too.

 

[Shield Arc]

Most welders have a timer where you set the amount of time for pre flow, before the power comes on. And you can set the amount of time for post flow.

 

[Sodo]

Not this welder, it's not much bigger than a welding helmet. It's all pre-set but I can change wire speed & voltage. I have to learn to work with the pre-sets.