Add a high freqancy arc plasma torch to a tig rig

[KingMT]

Wondering if it can be that you could just hook up a torch in place of the tig torch & supply air.

 

[Screwdriver]

No. It won't work.

What would you use to maintain the plasma? Hint: something that won't burn....

 

[KingMT]

No. It won't work.

What would you use to maintain the plasma? Hint: something that won't burn....

Doesn't the arc & air maintain the plasma?

I guess I'm missing something here. Can you explain a bit.

 

[WorkshopChris]

No wont work, its the equivalent to trying use to use a desk lamp to roast a chicken instead of an electric oven.
The oven may have a light bulb in and get hot and the desk light has a bulb in and get warm but that's as far as it goes they are completely different in operation.

EDIT in operation the plasma cutter will want to run at a much higher voltage and a low current.

 

[Tom Orrow L]

I have a feeling it has something to do with the OCV, @Jim Davey care to enlighten? This sounds like your sort of area

 

[Screwdriver]

Doesn't the arc & air maintain the plasma?

I guess I'm missing something here. Can you explain a bit.

In a TIG torch, the electrode is protected from burning by Argon. So unless you're going to use Argon, the tip is going to burn back to the nub.

You can use Argon at high pressure to simulate the effect of a plasma cutter but its expensive and without oxygen, the workpiece won't be burned away as effectively (it will also be protected by the shielding action).

Lastly a TIG torch runs at a much lower open circuit voltage (typically) and therefore has less penetration from the plasma jet than a plasma torch.

I had the same idea some time ago and unless you want to waste gas rough cutting tin sheets, you're better off with a dedicated plasma cutter. Dual purpose TIG/plasma units have dual power supplies incidentally....

S.

 

[KingMT]

I was thinking of using a plasma torch in place of the tig torch. Just using the inverted power of the machine & supplying compressed air.

I have a plasma inverter & know some machines have both in one. My plasma cutter is a 40A while my tig is 200A. This is what had me wondering.

 

[Screwdriver]

I was thinking of using a plasma torch in place of the tig torch. Just using the inverted power of the machine & supplying compressed air.

I have a plasma inverter & know some machines have both in one. My plasma cutter is a 40A while my tig is 200A. This is what had me wondering.

I believe the plasma cutter works at a much higher voltage, hence the corresponding reduction in amperage and why dual purpose units need a separate power supply to generate the different voltages.

 

[Richard.]

I'm no expert here but as said ocv is your problem or lack of. Iirc a plasma has an open circuit voltage of over 100v. Waaaaaaaaaaaaay more than used for tig.
The two processes are actually very similar and those of you that have tried plasma welding will appreciate that.

 

[KingMT]

Thanks. Good information guys.

I'm still wondering if it'd still do thin steel.

 

[Jim Davey]

Yes, so near but so far. Big difference in the voltage required to run a TIG arc compared to a plasma. I'm afraid the two are not compatible. However you can just about get a plasma to run a stick rod if you can fool it into keeping going (not recommended, but it's one way to check to see if the power source is working if the torch is faulty)

 

[Richard.]

Thanks. Good information guys.

I'm still wondering if it'd still do thin steel.

It won't produce a clean cut.
It will be exactly the same as melting through with too much current from a Tig torch.
You'd have more luck with stick electrodes. I've done that before cut sheet with 100 amps on a 2.5. when desperate

 

[Screwdriver]

Thanks. Good information guys.

I'm still wondering if it'd still do thin steel.

Yes. Heck, mine does it all the time even when I am welding!

I fear however if you bodge a plasma torch onto it, all you will discover is whether or not your TIG power supply will go bang.

 

[Jim Davey]

More likely it just won't produce an arc, volts = pressure. If you haven't got the pressure to make the plasma arc initiate then you'll struggle to get the arc to stay alive.

 

[KingMT]

Yes. Heck, mine does it all the time even when I am welding!

Thanks. It was all worth that laugh.

 

[Richard.]

Thanks. It was all worth that laugh.

It was a good question. Like I say. The power sources are very different but plasma and Tig as actual processes are not that far apart at all. I've done plasma welding as both a manual and automated process and it's pretty much Tig welding with a long arc. Great as a seam welding process too on an auto system.

 

[KingMT]

Yeah. That was why I was wondering.

I don't have much use for a plasma torch. I went 40 years before I had to buy a oxy/ acetylene torch. I'm still on the same tiny tanks I first bought with it. I've had the plasma torch for about 7 years & rarely drag it out. I was thinking if I could just use a torch on my tig I'd just give my plasma cutter away. Seeing how it's mostly in the way.

I also wanted something that used cheep consumables. I might still see if I can replace it with a cheaper plasma machine & give this one away. That is if I can find one that uses HF start & the consumables are cheap.

I really prefer to cut with a saw when I can. But I have used a stick welder cracked up to blow holes throw metal just to see if I could do it after learning about arc gauging rods.

I was actually thinking about just giving this a try but decided to see if anyone else had already been down that road. You guys saved me from buying a $10 torch. Maybe saving my machine also.