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worntorn
05-04-2010, 11:48 PM
I just switched to a wp9 torch from a wp 26 Trafimet style torch. Most of the welds I'm doing are on small diameter thin wall material at 40-50 amp, so the little torch and lightweight power hose are ideal.

This has made a big improvement in my control of the weld puddle. It's like trying to draw a house blueprint with a big dull carpenter's pencil then switching to a sharp drafting pencil, just a night and day difference.

The torch I bought is an ebay deal ,new in box with flex head and gas valve.
I don't see any need for the gas valve for my application, I'm doing all bench work and once the flow is set where it should be at the reg, why would I change it?

I can see that for remote applications such as boiler repair it might be handy to add a little flow as needed, especially if there was a breeze present, however without even a simple on off torch switch or preferably a sliding adjustable amp type, what good is this torch as a remote use unit?

It works fine for me, I just crank the valve wide open and set the argon flow via the regulator at about 12 cfh as with the other torch, but I'm curious about that gas valve and how it might come into use in certain situations that I'm not thinking of.

500HpSilverado
05-05-2010, 12:23 AM
It's used for welders that dont have an internal gas solinoid. it is basically useless on a machine with one internally.

SR20steve
05-05-2010, 01:09 AM
I hear you on the WP9/WP20. IIRC the 26 is even bigger than the 17 series and I really don't like using the WP17 on my sync, at work I use a WP20 and at home I find myself using my maxstar with the #9 torch unless I absolutely have to use the sync.

Supe
05-05-2010, 09:27 AM
Comes in handy if you have to make a weld using lift arc or scratch start in an awkward position without a pedal. When building cages and chassis, I use the pedal most of the time, no hand amptrol. On occasion, there are spots where I just can't use the pedal, so I go to a gas valve and lift arc.

worntorn
05-05-2010, 12:08 PM
"It's used for welders that dont have an internal gas solinoid. it is basically useless on a machine with one internally"

I didn't realize that there were any tig welder's built without a solenoid.
would this typically be a situation where someone has converted a regular stick welder to TIG?

I have been planning on converting my old P+H 400 amp AC back to TIG usage for aluminium. It was used for TIG welding in the construction of Dump truck boxes years ago. Right now it is just set up for stick.
It is missing the gas solenoid and foot pedal, but does have HF with control and a place for a remote pedal hookup.
Perhaps for that machine a torch with a gas valve is the way to go. Then the post flow would be controlled manually with the torch valve.
Seems like it would get to be a bit of a nuisance to turn that valve on at the start and then off after the end of each weld though!

Other than using this type of torch, I don't know how these old welders can be set up to have any post flow, it seems the gas soleniod (if I were to fit one) would normally shut the gas off at the same instant as the weld is stopped.

farmall
05-05-2010, 08:20 PM
In construction and pipe welding, the weldor may be far (as in "several stories" or "more than a hundred feet") from his machine. Control cables and pedals add a great burden of complexity in field work. Construction and pipe welding are among the most "remote" of remote uses.

Our students learn only scratch-start TIG, running off simple Idealarc 250s whose pointers are taped over. They learn to set heat by experience, they set it on scrap and then weld, and they don't need to trust or see "numbers on a dial" to make good welds. When they test out on a tired, fluctuating eight-pack dumped in a muddy shop yard, they pass because they trained on the basics and have become confident thereby.

The classic Tozzi post I show others for reference. All the parts are cheap and easily replaceable. Get a tee fitting (you'll see one in his pics hanging off the regulator) and two argon regulators instead of a dual regulator, so when one reg dies you can swap it out and press on.

http://weldingweb.com/showthread.php?t=38106&highlight=scratch+tig

worntorn
05-06-2010, 12:07 PM
interesting, thanks for posting that.

I have seen the gas fittings with the lug for sale on Ebay and other places and wondered what they were for.
With this arrangement I could set up to tig Aluminium for very little $
From what I've seen, I would be limited to about 200 amps air cooled, haven't seen any torches bigger than that unless they are water cooled.

200 amps should weld 1/4 aluminium which will cover most of my needs.

My old 400 amp P+H is a very basic machine, straight AC but it does have a HF switch and control knob.

I have a little 200 amp DC inverter tig for metals other than aluminium.

I was planning to set up a gas solenoid on the P+H but would need to add a timer of some sort in order to achieve post-flow.
I can see that the gas valve on the torch eliminates the need for both of those items.

With the HF on, I wonder if the arc will start without touch?

snoeproe
05-06-2010, 11:35 PM
farmall hit the nail on the head. Tig torches with a gas valve are basicly used with welding power sources without a gas solinoid built in. Most pipe welding and industrial construction tig welding is done with scratch start and large stick welding powersources. The gas valve on the tig torch is your on/off gas control you control manualy before you strike your ar and after breaking the arc.
I tig with my Idealarc 250 stick welder via scratch start with a tig torch that has a gas control valve on it. Simple and effective but no remote current control.

ccawgc
05-07-2010, 02:03 AM
IF you want a timer. Look at the older miller syncrowaves. they have a 115 volt timer module that could be wired in real easy. And it is adjustable. or buy a time delay relay and make you own.

worntorn
05-07-2010, 02:10 AM
I might buy a used Ebay 200 amp Torch with a gas valve and just try the machine the way Tozzi's stickwelder/tig setup is. The only differences are that my machine is AC and has HF.

I'm hoping the HF will make it possible to start the arc without touching the electrode to the work, seems a better way.

Also, the HF and AC will allow me to weld Aluminium which is what I want to use this machine for.

If it works well I might spend some $ on it and add the solenoid and timer later. Bill McCormack has a non working pedal he is sending me. If I can get that functioning I should have a machine that will tig aluminium for not much of an outlay.

farmall
05-07-2010, 09:09 PM
You can also run the same basic setup with water cooling.

Water hose to input, drain hose from output, no special valves or cooler, let the water run down the drain or elsewhere. You can add an independent cooler later if you like. Make good professional connections so as not to get sparky things wet.

"Stuff" has to be "connected" to work, but not necessarily "integrated". :)

jmtebbens
07-20-2011, 11:48 PM
I have an XMT350 I use out in the field. They don't come with the gas solenoid, it's a customer installed option. I actually grew accustomed to the manual valve and like it quite a bit now. I set my flow fairy high on the reg, and then choke back at the torch. Gives me some room to bump the flow up a little without stopping the weld if I need to.

Edit: Didn't realize this was such an old thread.