Purple/Bluish Tungsten

Bradk · Sun Mar 25, 2018 11:39 pm

Good Evening,
Had a question as to Tungsten color after welding a little on steel. Been working on a press break hydraulic frame for my garage shop. Doing some welding on parts of the press using my Everlast Tig 250 EX. Using 125 amps dc, 20 cfh argon flow and an Arc Time 3/32 Tungsten with 1/16 ER70S2 filler rod. Been getting a purple/bluish tungsten after welding for a while. I believe I am getting contamination from what I am welding? Cleaned material with simple green and then alcohol before welding. Symptoms seem to reappear again after resharpening tungsten. Any ideas?

Thanks,
Brad

Coldman · Sun Mar 25, 2018 11:51 pm

Increase your post flow till it stays shiny.
Min 8 seconds

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Bradk · Sun Mar 25, 2018 11:59 pm

Coldman,
Did not even think about that, believe that I have post flow set to about 4 seconds? Will turn up post flow time to a minimum of at least 10 seconds or so.

Much appreciated,
Brad

tungstendipper · Mon Mar 26, 2018 5:56 am

Make sure you haven't set your post flow to an .8 of a second instead of a full 8.0 seconds.

Bradk · Mon Mar 26, 2018 7:14 am

Tungste Dipper,
I will make sure to not do .8 seconds. I have pre-flow set at about 2 seconds. My Lincoln Squarewave Tig 200 has a non settable post flow which runs for quite some time to keep me out of trouble, new to the Everlast .

Brad

cj737 · Mon Mar 26, 2018 7:36 am

Rule of thumb is 1 second per 10 amps for post flow. Your SW will run for 12.5 seconds at 125 amps, maybe a tad longer than required. I usually set my machine to 10 seconds and leave it unless Im running around tacking only. Then its set to about 5 seconds to cool the tack/tungsten. It doesn't really end up costing you really $ in the long run for that extra argon.

tungstendipper · Mon Mar 26, 2018 7:51 am

Bradk wrote:Tungste Dipper,
I will make sure to not do .8 seconds. I have pre-flow set at about 2 seconds. My Lincoln Squarewave Tig 200 has a non settable post flow which runs for quite some time to keep me out of trouble, new to the Everlast .

Brad

I have a Square wave 200 and bought an Everlast (bought for this reason and more amenities) and I wondered why my tungsten turned black; and yup I had my my post flow at .8 seconds!

tungstendipper · Mon Mar 26, 2018 7:53 am

cj737 wrote:Rule of thumb is 1 second per 10 amps for post flow. Your SW will run for 12.5 seconds at 125 amps, maybe a tad longer than required. I usually set my machine to 10 seconds and leave it unless Im running around tacking only. Then its set to about 5 seconds to cool the tack/tungsten. It doesn't really end up costing you really $ in the long run for that extra argon.

Did not know this....
Thanks CJ!

hey_allen · Mon Mar 26, 2018 1:05 pm

Another possibility, if the increased post-flow doesn't fix it, is any possible shield gas leaks letting air be drawn into the shielding gas flow.

I was chasing this on a cheaper TIG setup that I bought used, and it turned out that the torch head rubber overmold had gotten hard and was no longer sealing against the back cap seal, and was allowing air to be sucked in.
Once I replaced the handle with a nice new CK, no more issues.