Welding Tips and Tricks

I am new to tig and have a dynasty 200dx. My first few times using it everything was going well and I was doing decent with aluminum. Then I went to use it another day with aluminum and all the beads were looking like some contamination even after changing flow rates and other things to fix the problem. Nothing helped and I noticed my tank only had about 100psi left so I thought maybe being the end of the tank there was a little contamination. I got a new tank the other day from praxair and I am having the same issue. And now I noticed if I have the welder off and turn the tank off, that the working pressure gauge will climb and the tank pressure gauge will drop down to zero within minutes. I thought maybe I had a leak somewhere after the gauge but that doesn't make sense because the low pressure size rises. I am lost here hopefully someone can help. Thanks

Is it contamination or porosity?

My first inkling is that your regulator has gone south.

I think you may want to take it to someone and have it looked at.

not porosity but a kind of sooty even on steel it didn't look quite right and the tungsten gets dark grey after I strike an arc with a fresh ground tip. When I run a bead on aluminum as the bead forms you can see some black floating around in it. The rod is new and clean, everything is new and clean including the regulator because I just bought the whole set up new a few weeks ago. I think the regulator has some internal issue to have the low pressure side build pressure when everything is turned off. But if anyone has ideas to try please let me know before I try buying a new regulator.

I'm thinking JMAuto has it right. Regulator issue.
I think the tungsten turns grey when it is hot in the presence of regular atmosphere, no argon coverage.
A friend of mine bought a new mig welder two years ago. He was running into intermittent porosity issues. Turns out he put Teflon tape on the hose connector threads to seal them. A little piece of the tape got into his system and was plugging things up from time to time.

This is just a thought. I've made this mistake myself. You mentioned you welded some steel. Is it possible you forgot to switch back to A/C after welding the steel. Welding DC- on aluminum, you won't get any cleaning action. All the oxides will float into your puddle. Good luck. Just remembered something else. If you know anyone else with a tig machine, try your tank with their machine. It wouldn't be the first time a tank was mislabled.

no I know I had it switched back and I think it has to be the regulator. I ordered a new flowmeter to try out. thanks for the help

if the outlet side of regulator rises then its the reg bleeding by. maybe dirty?