Melting Tungsten Electrod - Dynasty 200DX

Hello,
New to tig welding, and been trying to do some mild steel welding. However, the tungsten keeps melting into a ball before it gets hot
enough to weld. I have Dynasty 200DX running on 230VAC 50amp circuit with the CoolMate 3 and DiamondBack Torch. Welding 1/16" mild steel with DCEN. The Argon flow rate is around 15 at 20psi. The AMP meter on the Dynasty only reads 20-30amp before the Tungsten melts. The CoolMate is hooked up correctly, and the torch does not get hot.
Any recommendations on how to fix this problem? I read the TIG Handbook, and believe am welding correctly.
Thanks,
Luds
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On Sat, 22 Mar 2008 19:30:57 -0700 (PDT), snipped-for-privacy@charter.net wrote:

Try setting the machine for DCEP. If that works, you've got the torch and ground connections switched. A less likely scenario is the welder's internal wiring is reversed, or it's outputting AC instead of DC.
--
Ned Simmons

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I'll try the DCEP tomorrow. I checked the ground and torch connections and they match the manual. How would I check the welder's internal wiring?
Thanks,
Dave
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Dave, I was going to say put a DC meter on it, but the high voltage high frequency won't do it or you any good unless you can turn it off. The symtoms are definetly DCEP especially at such a low amperage. RichD
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That should work fine. Sounds like the machine is wired backwards or your lead connections are reversed. What tungsten? RichD
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The Tungsten rod has an Orange tip so it should be Cerium. How can the machine be wired backwards? I have followed the instructions for the plug with black and white wires to the AC lines, and the green to the ground or white wire. The electrode connections are correct in front of the unit. Ground is plugged into the ground terminal, and the torch is plugged into the electrode weld output. Should I call Miller for assistance? I've never been able to weld with this unit yet, but this is the first time I have tried TIG welding.
Thanks!
Luds
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On Mar 22, 11:08 pm, snipped-for-privacy@charter.net wrote:

The Dynasty has a Polarity Control with two settings. One for DC and one for AC. I selected the default DC. The manual states "Machine is set to DCEN (direct current electrode negative) for TIG weldign, and to DCEP (direct current electrode positive) for Stick welding. I selected DC, but how do I know if Stick or TIG is selected? I assumed TIG is default.
Thanks,
Luds
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On Mar 22, 11:08 pm, snipped-for-privacy@charter.net wrote:

I have the Process Control set to TIG HF Impulse so this should provide DCEN.
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Are you SURE the argon is on and the bottle HAS argon in it? Can you hear the gas blowing at the torch when you push the pedal down? NO argon = a mess when trying to TIG weld. Richd
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On Sun, 23 Mar 2008 08:26:31 -0700 (PDT), RichD

Definitely check the gas flow, though the original description "the tungsten keeps melting into a ball" is more consistent with incorrect polarity. Without gas the tungsten will erode irregularly in a blackened mess.
As Rich says, don't check polarity with a meter unless you're sure the hi-freq is off.
I'm not familiar with this machine, but it sounds as though polarity is determined by the machine based on the setting of a process selector switch? In that case, try setting the machine for stick welding DCEN (straight polarity). If you still melt the tungsten, try DCEP. Presumably that will disable the hi-freq start, but you can still scratch start, and perhaps get some clues as to what's going on.
--
Ned Simmons

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I check the electrode voltage and its negative 16VDC. The maximum Amp set is 70. The diameter of the electrode is 3/32. Am I just using too small of an electrode. The sheet metal thickness is roughly 0.065. Argon is flowing with a 7 second post setting.
Thanks,
Luds
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On Sun, 23 Mar 2008 15:44:05 -0700 (PDT), snipped-for-privacy@charter.net wrote:

Under what conditions? 16V is very low. I'd expect to see 60V to 80V open circuit, perhaps 30V while current is flowing.

1/16 is the right tungsten. 3/32 is too big.
--
Ned Simmons

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Luds, OK, I think I see your problem. That small of electrode can only handle very small current. Too small for 1/16 steel sheet. I hate to disagree with Ned, but a 1/16" tungsten is awfully small. For most work the 3/32 size thoriated or cerium is best. Keep it well sharpened to a point for welding steel. About 30* is fine. Anytime you are melting the tungsten, the current is way to high for that size. For welding aluminum, use pure (green) tungsten. Form the ball on a blunt end. Typically 1 size larger than steel. I am a student at a Tech College, but have been welding for many years. Owner Miller Syncrowave 250. RichD
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On Sun, 23 Mar 2008 17:26:03 -0700 (PDT), RichD

No harm in disagreeing, but you're way off here. A 1/16 thoriated tungsten is good to well over 100A on DC, at least twice what's necessary for welding 16 gauge steel. For stock thinner than 16 gauge, I'd be thinking about switching to a .040 tungsten.
There's a chart on this page: http://www.thefabricator.com/AluminumWelding/AluminumWelding_Article.cfm?IDR7

Better go at least two sizes larger if you're using pure tungsten.

I made my living TIG welding for many years.
--
Ned Simmons

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On Sun, 23 Mar 2008 17:26:03 -0700 (PDT), RichD

I'd say try a different tungsten.
I did some welding last week on 3/16" steel using a 3/32" lanthanated tungsten, running well over 150 amps to "get 'er going" because I wanted to be done in 15 seconds and quench before the heat got to plastic about 1.5" distant. No problems at all with the tungsten. (No problems with the plastic either.)
Miller Dialarc 250 HF, DCEN.
I like zirconiated tungestens much better than pure tungsten for AC on ally.
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Hello,
The electrode I have been using is a 3/32" 2% Thoriated. Do you think the Dynasty 200 DX unit is malfunctioning? Here are the specifics:
Input power is Single Phase 220VAC on 50Amp circuit (Upgraded from 30Amp circuit) DC Polority Measured -16VDC with the DCEN process Argon Gas Verified plug wiring. Verified torch and ground connections Diamondback torch Coolmate 3 Peak A set to 70.
Thanks!
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On Tue, 25 Mar 2008 19:29:08 -0700 (PDT), snipped-for-privacy@gmail.com wrote:

It's certainly possible that your machine isn't working right. 16 volts sounds quite low even with an arc running and way low for open circuit voltage. That sounds more like a MIG machine at a low setting.
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Thanks for all the help! Finally figured out the problem! The Dynasty 200 DX machine works great. The only problem was the guy holding the torch. With some lessons from a very experienced professional all is working. The most significant problem was the incorrect face shield for the job. Its so much different than MIG or ARC welding. Plan to buy new face shield with fixed gold shade of 11 with magnifier followed by more hands on practicing.
Luds
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On Wed, 26 Mar 2008 19:06:34 -0700 (PDT), snipped-for-privacy@gmail.com wrote:

IOW the whole problem was a loose nut behind the torch.
Been there, Done that, Have the book, Saw the movie, the book was better, the movie was totally mis-cast...
--<< Bruce >>--
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On Wed, 26 Mar 2008 19:06:34 -0700 (PDT), snipped-for-privacy@gmail.com wrote:

The best investment by far you can make at this point is an autodark welding mask.
Gunner can recommend best buys.
I've been welding for decades now, did plenty of it by head-nodding. Then I got an autodark. If my Jackson autodark crapped out, replacing it would be high priority.
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