[Des]

Hi all,

regarding the anathomy of a water cooled tig torch, it seems that the electrical power cable is also cooled by a water jacket.
Is that cable directly surronded by the water, or is it still (electrically) insulated from the water jacket?
If it is directly surrounded by the cooling water, ok for the welding voltage, but is there any danger to damage cooling components from the cooler when using HF start?

Kind regards,
Frans.

[Braehill]

Frans,
Any water cooled torch I've encountered has had a tube run inside of a woven cable surrounded by tube of some sort to insulate it from short circuiting. The cooling water actually should never come in contact with the power cable, and therefore I don't think HF has any effect on the cooling circuit at all.

Len

[Otto Nobedder]

Frans,

I have to contradict Len, unfortunately.

I have dissected several WC torches to scavenge components (for emergency fixes at work), and it's quite common for the power lead to be directly in the water path. The power-lead is normally in the coolant return from the torch.

This is why every torch maker specifies distilled water and "low conductivity" coolant in a water-cooled torch. I destroyed several expensive superflex torches in Pennsylvania because I assumed the local rental company knew this. For DC welding, and even in HF-start, the damage is slow, but I was welding aluminum 10+ hours/day, and the HF would destroy a torch in as little as 30 hours at high currents.

Steve S

[Wes917]

Frans,

I have to contradict Len, unfortunately.

I have dissected several WC torches to scavenge components (for emergency fixes at work), and it's quite common for the power lead to be directly in the water path. The power-lead is normally in the coolant return from the torch.

This is why every torch maker specifies distilled water and "low conductivity" coolant in a water-cooled torch. I destroyed several expensive superflex torches in Pennsylvania because I assumed the local rental company knew this. For DC welding, and even in HF-start, the damage is slow, but I was welding aluminum 10+ hours/day, and the HF would destroy a torch in as little as 30 hours at high currents.

Steve S

This has been my experience also fwiw. I've dissected a few where the water wasn't turned on.

[Rick_H]

Correct, recently ripped apart a CK and that is what I found as well.

[Braehill]

Frans,
While my original statement was true, I just went to the garage and checked the CK torch cable that failed on me last year, it has as the others have stated, the power cable running through the water. I was not trying to be misleading. I should have taken my own advise and researched a little further before I responded, sorry.

The only other cables I've dissected were an old Union Carbide 400 Amp torch (think heavy) and another unknown brand (think heavier) that was on the shop welder that was an old 600 amp transformer. They were both made as I originally described. Maybe these higher amperage torches were made different, or maybe it's the time frame they were made. I can see where it would be way easier and I assume cheaper to just run the power cable through the water jacket.

Len

[Braehill]

Now you guys have me thinking, I have 2 brand new (as in never used but have been there awhile) Weldcraft 500 amp #12 torches on the shelf in the garage and I'm wondering which way these higher amperage cables are made, internal cable or braided over. Sorry, not willing to cut one open for the cause though. Might have to do some research though.

Len

[Des]

Hello all,

many thaks for your replies.
In the meantime, as I had a new torch assembled by the weldshop, I asked these people also about the subject.
One thing is clear now, Yes, the power lead of a water cooled tig torch is directly surrounded by a water barrier.
(At leased all the ones they have ever assembled)
BUT, about the effect of the HF nobody could come up with a closely reasoned argument...
Anyway, I keep the subject hot, and will post my findings if I ever should come across a reasonable explication.

Kind regards,
Frans.

[Bill Beauregard]

What I say is contradicting everything you, and I have ever been told about water and electricity. Pure water is a poor conductor of electricity. Impure water is a fair conductor. Manufacturers call for deionized water in coolers. this is all we need for OCV in welding. When we get into HF which I don't understand how the spark gaps, with a few other internal components turn 240V, 60 cycle into thousands of volts and something like 1200 cycles per second. I will compare it to a basket ball being dribbled. Bounce the ball from 5', it bounces at a predictable rate. Move your hand toward the floor, you must move your hand faster. By the time your hand is just above the top of the ball, your hand must move very fast. High voltage is enhanced by high frequency to overcome electrical insulation. Very high voltage tends to go where it chooses to go. We are not without resources when we herd electricity. It is lazy. It takes the easiest path. Your TIG welder offers both low frequency, and high frequency simultaneously. HF creates the path by ionizing the gas, low frequency follows the path.

It is easier for HF/HV to run to the end of your tungsten, then cross a short bit of conductive, ionized gas to the other end of the circuit, (your grounded workpiece), than another route. When a narrow gap is available, it won't choose water as the easy path.

I have had my ground lead pop off the work, the torch in a holder, isolating the tip of the tungsten by inches from any conductive object, touch the pedal, it arcs inches into thin air. It might arc to me if I'm too close to the tungsten.

[Bill Beauregard]

If the cable is wrapped in anything it is to protect it from oxidation. The hose containing the water is an electrical insulator.

[AlexG]

If the cable is wrapped in anything it is to protect it from oxidation. The hose containing the water is an electrical insulator.

yeah that's rite u seems to be well qualified physics professor

[Otto Nobedder]

If the cable is wrapped in anything it is to protect it from oxidation. The hose containing the water is an electrical insulator.

yeah that's rite u seems to be well qualified physics professor

Don't be an ass. It doesn't fly, here.

The man was trying to be helpful, and he was correct about the outer jacket. A wrap directly on the conductor in the water path is there to prevent that conductor from abrading the water jacket and wearing it prematurely.

Steve S