What causes a grey colored TIG weld?

[blueeyeddevil]

So I'm welding on a miller 250 squarewave. I'm cleaning, grinding, sanding, brushing, and wiping down with acetone. I can't get a "clean" weld to save my life. It's been a while since I did any TIG ( Been an ironworker for awhile, got my G3 & G4 certs.) What am I missing?
CFH= 15-20
DCEN
AMPS= 80-100 or so....
3/32 tungsten and 1/16 70-s2
Thanks in advance

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[garage_runner81]

i think its to much heat.... what size metal are you welding?

[tomahawkracefab]

too hot outside of your gas shield , amp down and slow down movement maintain penetration , try a larger gas lens on your torch for better gas shielding , binzel make a cheap and easy flowmeter to check cfm @ torch tip , some times you can lose a few cfm's through long/faulty leads

[blueeyeddevil]

I'm welding everything from 18-16ga plate, basic 1/8" tabs, and .083"-.095" tubing;both DOM and ERW.
The weld will look nice and clean some colors. By the end of the post flow (about 6 secs or so), it turns gray.

[Chase 2]

Bad bottle of gas??

[Demp]

Bad bottle of gas??

That's what I was going to say!

[tmathews]

Try taking the cylinder back to your gas supplier and see if they can run a purity analysis on the gas. Also, see if they will exchange it for another cylinder of gas.

Also, try turning up your CFM to 25 to 30.

[blueeyeddevil]

maybe???? We did get a new bottle a couple weeks ago. I hate to blame problems on tools or the like, because most of the time it is an operator error.

[tmathews]

Just thought of something else... Check all of you lines for leaks... Gas hoses.. tig torch. etc.. One little pin hole can make a difference.

[Chase 2]

Although I don't think that it is the problem in this case, but sometimes too high a gas flow can actually cause problems.

If its not the gas, then most likely you're too hot and too fast.