Troubleshooting Tig problems

[walker]

I finally got my TIG torch connected to my trailblazer. When I tried it out I burned about 1/4" of the tungsten off on the first weld. It would then go along okay for a few seconds then burn off another 1/4" of tungsten. There is also a lot of tan slag/ash type material around the weld area. It is a 200 amp torch, with 1/16" 2% thoriated(red) tungsten. The welder was set at about 90 amps, DCEN, with the process selector switch set to TIG. I am using straight argon, at approx 20cfh(although this is up for debater, as the gague I am using is not the greatest). The material I was welding on was 1/4" mild steel. I know the tungsten needs to be thicker (1/8"??) to weld 1/4 steel, but I was only striking an arc to get the bugs worked out not doing any actual welding. I tried lowering the amps, and changing the polarity wit little change in the results. So, what a I doing wrong?

[Mike W]

I would check the gas flow. Was there any wind present?

[walker]

No, no wind. I was doing it inside my garage. I just didn't know if an eroding tungsten was a sign something wrong with the setup, or if it was a technique issue.

[eric75]

I've only seen that when there was no gas flow. You should be able to hear a hissing sound.

[dyn88]

i agree also. check all your connections with a solution of soapy water for sudsing. also try dunking your torch hose in a bucket of the same water.

[Paul Seaman]

I had a similar problem when a classmate clamped my hose off.

[DSeckt]

I just did the same thing last nite !! Was welding on the car and wife called me in for Dinner... I turned the gas off.. Came out a 1/2 hour later and started welding again.. Got real hot.. with the Gas off.. Back to the grinder..

[walker]

I have gas, it is just the dubious nature of my guage that I am concerned about. I'll turn the gas up and give it another try.

[VBI]

I finally got my TIG torch connected to my trailblazer. When I tried it out I burned about 1/4" of the tungsten off on the first weld. It would then go along okay for a few seconds then burn off another 1/4" of tungsten. There is also a lot of tan slag/ash type material around the weld area. It is a 200 amp torch, with 1/16" 2% thoriated(red) tungsten. The welder was set at about 90 amps, DCEN, with the process selector switch set to TIG. I am using straight argon, at approx 20cfh(although this is up for debater, as the gague I am using is not the greatest). The material I was welding on was 1/4" mild steel. I know the tungsten needs to be thicker (1/8"??) to weld 1/4 steel, but I was only striking an arc to get the bugs worked out not doing any actual welding. I tried lowering the amps, and changing the polarity wit little change in the results. So, what a I doing wrong?

You say you tried switching the polarity from Straight Polarity (Electrode Negative) to Reverse Polarity (Electrode Positive). You should have experienced a big difference with Electrode Positive as 1/16" tungsten at 90 amps should at least ball the tip over instantly if not disintegrate rapidly. Is your machine switching Polarity proberly?

[walker]

It looks like the concensus is lack of shielding gas. That is a good question about the machine switching polarity. I have typically only run it on dc reverse polarity for stick welding. I suppose I will now have to get the multimeter out and check into that. Since it sounds like the electrode will erode quickly from either no gas or wrong polarity then I would suspect no gas, but I'll check them both.
The reason that I suspect my gauge is that the regulator/ gauge is not really designed for this. It is an inert gas regulator, but not a flow gauge regulator. There is no restrictor in it and the low pressure gauge reads from zero to five hundred pounds. So, I used a variable restrictor downstream of the gauge. I calibrated it from the flow gauge regulator on my MM185, made a chart of the pressure vs. flow from the flow gauge and set the pressures on the modified regulator to match the MM185 regulator. The problem with that is that the modified regulator has too stiff a spring to be real accurate, I calibrated it using a blended gas but am welding with straight argon, the gauge has 20 pound increments yet has to be adjusted between 15 and 30 pounds, and on and on. So now you know why I suspect the reg.
I work with orifices and pressure regulation for a living but 20,000 cfh would be considered low flow for what I do, so getting something to flow at 20 cfh for me is a pain, yet I cannot admit defeat. I don't know why I have such a hard time just going and buying one, I have spent two hours modifying something to work that I could have bought for an hours worth of wages, and it would work better. Guess I'll go buy one tommorrow!

[Mike W]

Just look at the fun you have had, forget the time. Let us know the outcome. I am working on a argon/CO2 gas mixer.

[Paul Seaman]

Walker swap the mm185 regulator in for the suspect regulator and see if the problem is fixed before you spend bucks for new one! If the problem is exactly the same then it isn't the regulator---right!!!!

Peace,