PT60 electrode issues - tip blowing off??

[chadmjohn]

I have no idea why this is happening, but I am having electrodes routinely blowing out in my Everlast 50s. I made a quick video showing the cut issues and an example electrode.

The machine will be cutting just fine, then in the middle of a cut simply stop making it all the way through the material, suddenly resuming the cat a few inches later. I'm getting maybe 30-45 minutes of cutting before the electrode blows out. Normally I would suspect water, but I have extremely dry air. Normally at the point of the failure the compressor has been running, on and off, throughout and I would suspect water, but the desiccant in the final stage of the compressor output (3 stage filter) stays blue and the last water trap on the plasma cutter is bone dry.

I'm cutting 16g mild steel at 300ipm and 40 amps. I have a machine torch with shielded setup using the components outlined in red below:

Screenshot 2022-09-28 131415.png

Here is an example of the cut issue and my electrode. I would love any feedback as to why this may be happening.
https://youtu.be/S_tJ5cVoYZA

[acourtjester]

I would see if you can blow air through the torch (unconnected from the machine). with a white rag over the other end. You may have oil from the compressor getting through. You would think the filter would trap any, but oil is the only thing I would think would damage the electrode like that.
Or a bad batch of electrodes, but that does not explain the cut failures during a cut operation.

[chadmjohn]

I would see if you can blow air through the torch (unconnected from the machine). with a white rag over the other end. You may have oil from the compressor getting through. You would think the filter would trap any, but oil is the only thing I would think would damage the electrode like that.
Or a bad batch of electrodes, but that does not explain the cut failures during a cut operation.

I had not thought of oil, since there is nothing in the oil/water separators (yes, multiple), but who knows, maybe somehow something is getting through.

I'll try your suggestion, a blue shop towel would works well, they change quite a bit darker when they get 'wet'.

[chadmjohn]

The 'paper towel' test has been running for 30 minutes straight, not a drop of anything on the paper towel.

Thought I'd add something I just noticed. I was running about 60 PSI of air. I think for this amperage and speed that may be too low. Maybe it wasn't blowing the molten material away fast enough? If it accumulated between the shield and nozzle, could that do anything? I wouldn't think so since the shield is electrically isolated from the torch body.

[acourtjester]

what normally happens with metal ejection it will attach to the nozzle and deform the plasma stream for bad cuts not cause electrode damage. Hypertherm wants at least 85 PSI I would bump it up from 60. Have you posted the question on the Everlast Blog to see what others who use them have to say??

[adbuch]

I run 100 psi as measured with an inline pressure gauge attached to the gas inlet port on both my Hypertherm Powermax 85 and 45xp. I agree with Tom that your 60 psi setting sounds low. You cutter should have an internal pressure regulator to adjust for the actual air flow requirements for your cutter.
David

[chadmjohn]

I'll be testing with higher pressure next. I can see how a low pressure could cause both electrode failure and cut inconsistency. If there isn't enough pressure to hold the electrode back it could move and impact the cut (by essentially cutting off the arc until it blows back again). That same thing will definitely cause electrode failure like I'm seeing. Hopefully it's that simple!

[adbuch]

I will be looking forward to hearing how you come out with the higher air pressure.
David

[chadmjohn]

Well, no luck, still blew out the electrode after about 30-40 mins of cutting at 75 psi (manufacturer recommended). There is still zero evidence of moisture from my compressor in the air / water separator on the back of my plasma cutter.

I'm at a loss as to what is going on. About the only thing I can think of is that the torch head is failing and maybe the blowback feature is not working as it should. No clue what is going on though....

[weldguy]

I know you are seeing nothing in your air/water separator on the back on the plasma however the swirling stains on the electrode are an indication of contamination getting past your filter system. The dark stains are carbon deposits from something burning up.

I would like to see what you are you using for an air/water separator if you could post a pic.

Any contamination can cause super heating of the electrode which can cause the end to blow off where the hafnium is inserted.

I suspect the manufacturer of your plasma cutter has a recommended air pressure, I would just stick with that. 60 psi does sound low to me.

[chadmjohn]

Here is a video I put together about the compressor setup. From the compressor head output, it goes through a fan driven heat exchanger. the fittings on the head are approximately 200F and when it exits the heat exchanger it is down to ambient temp, the water is then removed via an air water separator before it enters the tank.

On the way out of the tank it goes through a three stage air - water / oil separation (2 stages) and then a desiccant before going to a final air/water separator on the back of the plasma cutter. The desiccant stays blue and there is never even so much as a drop of water in the separator on the cutter.

I'd love to hear your input to help identify where this may be coming from.

https://youtu.be/0OXqBHT7lI4

[chadmjohn]

I think I found the root cause of my cut quality issues and inconsistency! My torch was in BAD shape internally. That kind of sticking will DEFINATELY blow out electrodes!

Check out this video of what was going on:

https://youtu.be/jj31TfKkOsc

A new torch is on the way!

[weldguy]

Interesting find. Hopefully that is the issue and you can get it clean and functional again. Curious how it works out for you.

[chadmjohn]

Interesting find. Hopefully that is the issue and you can get it clean and functional again. Curious how it works out for you.

I was able to get it moving again and it seems like it may be ok. I'll be testing soon, but I had already purchased a new torch a few days before finding this issue.

I'll be making a few test cuts to see if this fixed it, but in the end, the new torch head will get installed. I'll just keep this one for an emergency backup.

[djenkins62]

Hello everyone, learning from comments, thank you. Should you be blowing tips from moisture.......I would suggest to review your filter technology.......not all water absorbing or adsorbing filters are created equal.

Steel Camel

[adbuch]

Hello everyone, learning from comments, thank you. Should you be blowing tips from moisture.......I would suggest to review your filter technology.......not all water absorbing or adsorbing filters are created equal.

Steel Camel

Welcome aboard djenkins62! Perhaps consider creating a post in the "Introduce Yourself" section of the forum and tell us a little bit about yourself, what table/cutter you are using, which software you like to use (or are learning to use), and what sorts of projects you are working on. Photos are welcome.

https://www.plasmaspider.com/viewforum.php?f=147

Thanks,
David