Need some assistance with plasma torch

After visiting one of the sci.engr.joining.welding posters today (thanks Rob!) I have a much clearer idea of what is plasma
cutting. For example, I realized that a jet of plasma should be coming out of the head even at a distance from the "work" (from the pilot arc).
Now, I have a question regarding my mystery plasma torch.
Here it is:
http://igor.chudov.com/projects/Welding/12-Plasma-Torch/
Wayne once said (using a much worse picture) that ``Looks a lot like the Zap Plasmatherm copy of the old Hypertherm 100 amp torch that I got for my old Linde PCM-100 plasma cutter. It didn't work on that machine is the only thing I can say about it.''
In any case, my main question centers around two compression fittings. One is electrically connected to the tip, another to the nozzle.
Can I use this torch by supplying compressed air to BOTH of these fittings (I realize that one is connected to the tip and another to the nozzle, to make a pilot arc, so proper electrical isolation etc will be necessary).
Or is this torch supposed to be used with two different gases?
All I want for now is to make a small pilot arc, that would be a good first step.
thanks
i
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On Wed, 12 Jul 2006 03:41:43 GMT, Ignoramus21261

As long as the torch uses a hafnium electrode air if fine in both (if tungsten then you've got another problem). These torches where designed as a conversion for the old plasma rigs to convert from a two gas setup to air.

Not if it's like I think it is. In fact you might want to double check that air can even flow on the nozzle line when all the tip and shields are on the gun. I know that the one I had didn't have anyway for the air to flow through the shield when it was in place though the passage did come of the gun itself.

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Which, I am now certain, is true.

I see.

I think that it cannot actually flow through the second line. I will check more tonight. Thank you Wayne.
i
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One thing to try for fun and us - is a good rod of Zirconium (Tig IIRC) as a source. It is tough, and has a high source of electrons - Hf is far better - another shell larger - and further from 'home'. But perhaps it can be a low cost and somewhat low current source for special projects or small stuff.
I know that Hypertherm uses Hf in my Plasma.
Martin
Martin H. Eastburn @ home at Lions' Lair with our computer lionslair at consolidated dot net NRA LOH & Endowment Member NRA Second Amendment Task Force Charter Founder IHMSA and NRA Metallic Silhouette maker & member http://lufkinced.com /
Ignoramus15962 wrote:

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