[FirstEliminator]

Tonight, April 25th 2020 I struck my first TIG arc. The Miller Syncrowave 300 I have is possibly of 1980 vintage. I held the TIG tip close to the workpiece and nothing happened--on-off-on-off the pedal. Holding the pedal on, I got it a little closer until it touched the workpiece, then the arc started and stayed with a plume. With no filler I smelted in a saw cut in the mild steel I was practicing with and it looks o-k for a first timer. Still, the welder would not start an arc without first shorting it on the workpiece which would burn back the point on the tungsten. I turned on the Hi-Freq start and tried to make other various adjustments to see if I could do what I see the youtube heros do. ("youtube heros" is not a knock against them. I don't have anyone here to give me any guidance, so watching knowledgeable guys on video is the best thing going.)
Then, it wouldn't start an arc at all. Not sure if something tripped? I turned the power switch off and on a few times to see if anything changed. I then realized there is no coolant in the system with a #20 torch. The torch wasn't feeling hot, or even warm. I was wearing blue nitrile gloves which provide almost nothing for temperature insulation. The combined duration of welding was maybe one minute. I was wondering if whatever wire in the coolant line got over heated because of the no coolant? I measured ohms between the tungsten and the cooler hose block at the electrode lug and found 2.6M ohms. I'm not sure exactly what is in the hose for conductor. Is there supposed to be resistance? My thought is it should measure 0 for continuity. Any thoughts?
Can I hook up a stick welding clamp to the "electrode" lug on the machine to verify if the rest of the machine is still working or as a means to isolate the problem to the torch and hoses?
If the it's the problem, I wouldn't mind replacing the torch and hoses with a 25 ft or more set. Then, of course fill the coolant whether it was the cause or not.

thanks in advance for any advice on this,
Mark

[TraditionalToolworks]

Mark,

No expert and without pics hard to say, but my guess is your electrode got bugger'd when you stuck it to the metal.

Try resharpening or using another electrode, then try again.

[FirstEliminator]

Hi Alan,
Thanks for the quick reply. I did try resharpening the electrode. Still, ther eisn't even a spark when I touch the electrode to the workpiece. My feeling is something is off or failed. Just need to narrow it down.

Mark

[FirstEliminator]

Here is what I just tried. I turned on the welder. Using a volt meter Between the workpiece and the tungsten, the voltage measured -56 volts. Test between the workpiece and the electrode lug and it is -71 volts. The negative number is just because the polarity of how I attached the volt meter. To further test, I kept the volt meter between the workpiece and the electrode lug on the machine, again with full pedal it read -71 volts. While holding the pedal I shorted the tungsten to the workpiece. There was no spark at the tungsten tip and the voltmeter continued to read -71 volts with no variation. It sounds like the problem is in the hose or torch. I'd like to hear a confirmation of "yeah, you !@#$%^&*, that's what happens when you don't have coolant".

[TraditionalToolworks]

What about the ground? You gotta have a ground.

[FirstEliminator]

Yup, good ground. Definitely the torch/hoses. I was about the walk out the door and head home and spotted a set of jumper cables on the wall. I pulled them down and got out a piece of welding stick. Hooked the jumper cable to the Electrode lug on the machine and struck a hefty arc with the stick.

Now, the question is Did I ruin a good torch/hoses because of attempting to weld with no coolant? Or, was the torch already worn out and using no coolant was the straw that broke the camel's back?

thanks,
Mark

[Oscar]

Now, the question is Did I ruin a good torch/hoses because of attempting to weld with no coolant? Or, was the torch already worn out and using no coolant was the straw that broke the camel's back?

thanks,
Mark

Either way, the power hose/cable assembly is smoked if you measured 2.6 MΩ. On my 25ft water cooled tig torch setup, I get 0.3Ω. So yes, there definitely has be continuity. Start looking for a replacement power cable assembly, do a complete clean/flush in the cooler system if it has been neglected, and replenish with specified coolant/fluid.

[TraditionalToolworks]

I'd probably check all the connections to make sure none of them are corroded all up before going out and buying a new hose/torch. Definitely you should freshen up the coolant, but not sure that would prevent arc. Sounds more electrical than it is cooling.

[Poland308]

I’d separate the torch from the power cable. It’s probably just the torch head.

[Simclardy]

You did not burn up a torch, unless the torch was hanging by a thread. The torch will get hot before bad things happen.

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[Simclardy]

As oscar pointed out you do have a problem with your torch based on resistance test. Poland is probably right, check the head. The cable is not the weak point. Connections and the tube inside the head. Not to say the cable did not soak in glycol for 15yr and rot. Lol
Cheers

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[Oscar]

Without pictures its hard to say, but most tig power cable assemblies have a ~16awg copper wire inside. Without coolant, this wire will fry with anything more than about 50A for a minute or so. If surrounded by coolant but not being pumped, it would survive a little bit more before the coolant boils and then it would still go kaput. All other things being assumed to be in good shape then I still say its the power cable assembly. Until Mark checks everything 100% to verify otherwise, I think it's the cable. Something tells me he used at least 100A.

[FirstEliminator]

Yes, it was at 150a. I started at 70 amps trying to imagine the setting I'd use with mig or stick. I kept turning the amps up hoping the arc would appear without shorting the tungsten.
I wonder if the wire was corroded. There was residual liquid in the hose since I got the welder 6 years ago. It could have been hanging on by a thread. There was no odor of melting plastic from the wire over heating in the hose. If there were corrosion on the wire,maybe that is why it wouldn't light the arc without touching?
Last night I ordered the CK Worldwide 250 amp water cooled torch from this site.
A lot of people seem to like the RV antifreeze for coolant. Is that still the current consensus?

Thanks,
Mark

[Oscar]

I kept turning the amps up hoping the arc would appear without shorting the tungsten.

That doesn't work without high-frequency; the arc is initiated via an ionized air gap created by the HF discharge. In automobiles, ignition coils simply overpower the air-gap with raw voltage around 30kV; in TIG welding you either ionize the air gap via a high-frequency discharge, or you initiate the arc via shorting the circuit to create the initial spark. The only other way is via very high temperature of either the anode or the cathode to cross the threshold needed for thermionic emission, which is not very practical in TIG welding.

I wonder if the wire was corroded. There was residual liquid in the hose since I got the welder 6 years ago. It could have been hanging on by a thread. There was no odor of melting plastic from the wire over heating in the hose. If there were corrosion on the wire,maybe that is why it wouldn't light the arc without touching?
Last night I ordered the CK Worldwide 250 amp water cooled torch from this site.
A lot of people seem to like the RV antifreeze for coolant. Is that still the current consensus?

Thanks,
Mark

I use just a smidge of regular Prestone auto antifreeze in mine; less than 10%. I have two coolers running like this (one nearly 7 yrs old, one about 3 yrs old). They still work.

Good call ordering the CK water cooled torch. Just eliminate the issue altogether, and you can get back to learning to TIG weld instead of placing another project in front of your learning.

[FirstEliminator]

Thanks for the technical reply. So I would need to have Hi-freq switch set to start or continuous for welding steel?

10% prestone, with the 90% being distilled water?

Thanks,
Mark

[Simclardy]

Without pictures its hard to say, but most tig power cable assemblies have a ~16awg copper wire inside. Without coolant, this wire will fry with anything more than about 50A for a minute or so. If surrounded by coolant but not being pumped, it would survive a little bit more before the coolant boils and then it would still go kaput. All other things being assumed to be in good shape then I still say its the power cable assembly. Until Mark checks everything 100% to verify otherwise, I think it's the cable. Something tells me he used at least 100A.

Where do you get the 16awg from? Hard to believe. In any event i have welded with 150amps without water running with no issues. I don't do it anymore, but when i started i would do it all the time.

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[Oscar]

Without pictures its hard to say, but most tig power cable assemblies have a ~16awg copper wire inside. Without coolant, this wire will fry with anything more than about 50A for a minute or so. If surrounded by coolant but not being pumped, it would survive a little bit more before the coolant boils and then it would still go kaput. All other things being assumed to be in good shape then I still say its the power cable assembly. Until Mark checks everything 100% to verify otherwise, I think it's the cable. Something tells me he used at least 100A.

Where do you get the 16awg from? Hard to believe. In any event i have welded with 150amps without water running with no issues. I don't do it anymore, but when i started i would do it all the time.

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It's my guesstimate based on pictures people have posted online when they fried theirs. It's a tiny conductor; water's specific heat capacity is what enables it to handle 250A without melting when it is being pumped in from an ambient temperature reservoir.

[Simclardy]

I understand the water dissipating heat. I pictured a braid similar to the outer shield on a coax cable. Never actually saw one opened up. Be curious to see if ck worldwide is different than a knock off brand?

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[Poland308]

I have cooked more than a few torches. They tend to melt down inside the molded part of the torch. Cables are almost all the same other than the extra hoses inside the water cooled ones. The coolant lines really only cool the torch head, yes they may pick up some heat from the cables but that’s minimal. The heat stress is almost always in the head. I’ve cooked 8 or 10 torches but only one cable.

[FirstEliminator]

Yesterday, I received the new CK torch and hose set for the tig welder. I got everything hooked up. This time, I made sure to fill the Miller Coolmate 3. I turned it on and nothing. It would trip the breaker on the machine. The unit was brand new, but sitting around for who knows many years. I took the cover off and noticed each time I flip the switch, the fan would move a little and then nothing. I turned the fan by hand and it was hard to turn. Flipped the switch on again and now it runs. Not sure what was hanging it up? Now, it doesn't trip the breaker. I'm watching and watching waiting for the impeller to spin and nothing. It doesn't fill the chamber with coolant. Refer to the manual if there is a bleed procedure and nothing, just plug in a go. Wondering if there was something wrong with the pump as to why the fan was stuck and it doesn't move fluid I thought about taking the cover off again. It does slightly move some fluid up and down in the filter. I take the hoses off and blow through with some air. It is really hard to blow through the torch. Coolant made it's way into the hoses and of course now it is dripping on the welder and the bench. I took an extra hose and looped the inlet and outlet on the cooler and it moves the fluid pretty good, the sight wheel was spinning like crazy. Glad the cooler is working. There must be a restriction in the lines. I continued to check with the compressed air and make sure all the connections are set-up for the proper flow path. It was a mess with coolant. I blew air into a line that had some coolant into it and shot a stream into my office all over the window and door. Eventually I got things put back together with only one line off and turned on the cooler to have it purge into a bottle. Great, it's working. I hook it up and look at the sight wheel and it turns for a second, but then stops. What the heck? Did it clog again? After another 20 minutes of fooling around I realized the coolant only flows when the argon is flowing.
Now, the welder and the bench, along with the floor, door, wall, window and myself are soaked in coolant I am ready to try out tig welding. Guess what? It doesn't spark. scratch it around and there was a very tiny spark intermittently. Flip around all the switches on the machine keep trying to do something to make a difference----nothing. I get out the ohm meter. I check ohms from the electrode lug on the machine to the tungsten. 5M ohms. Well, it isn't the torch now. Narrowing up the distance between the meter leads on the circuit I find there is a fuse in the block where the cooler hose connects to. This is where the source of high resistance is. This time, I get two hose pinch-off pliers to minimize coolant dripping. Take apart the fuse portion and it is very corroded. I reassembled without the fuse. Now it works. Perhaps this means the previous torch is o-k? I will save it for later.
For a few hours I was welding and trying to get a grasp on getting a feel for this. Gotta be good at the old game Operation to be a tig welder. I balled up the electrode so many times I started using a drill to spin the tungsten while at the bench grinder. A sharp point certainly does make a difference on where the arc goes. In one video I saw Jody twist up some mig wire to use as filler. I did that and it didn't twist quite as well as in the video. Some portions of the twisted wire would spring apart as I fed it. Then I started using coat hanger. The coat hanger probably had contaminates as it would make the puddle a bit bubbly.
It's about 1am by this point. Burnt finger, still damp with coolant and tired of walking to the bench grinder I decided to head home. It was fun. Hopefully I can identify where my technique needs the most help and eventually improve.

thanks,
Mark

[Oscar]

Thanks for the technical reply. So I would need to have Hi-freq switch set to start or continuous for welding steel?

10% prestone, with the 90% being distilled water?

Thanks,
Mark

That is the rough percentage I use, but I don't recommend it to anyone else. I sometimes take chances on my own things that perhaps others shouldn't with their things. It's your call. Not recommending it in case your stuff lets the magic smoke out, lol.

For high-freq, if you are using DC (in either polarity), you only need it to start the arc. It ionizes the air gap just slightly, enough for the arc to actually initiate, and when it does, then it shuts off. For AC, you might need it continuous, you might not. The way you know is if you have it set to start-only, and your arc extinguishes after the initiation, then you need to change it to continuous. It all depends on the welder. Square-wave outputs likely don't need it to continuous, but older sine-wave AC power sources more than likely need it.

As for the old torch/power cable still being good, perhaps. I suggested it was smoked because no other information/pictures was given until after the fact (about the corroded fuse holder, etc).

As for getting better, you will, so long as you practice properly. In this whole thread I only saw one picture. A picture is worth a thousand words. You can easily get more specific help if you show pictures and accurately describe things (not saying you don't), I'm just saying because a lot of people who ask for assistance are unaware that they need to disclose certain things very very carefully and accurately. I'm not the best weldor, I know my own technique flaws, but the important thing is I know where they lie.