Hello all. I have been trying to find an answer for this assumingly easy question, but cant seem to. I need to reglue this wire to the tube and dont know what kind of glue/paste this would be. I have been seraching “co2 laser + thermal glue” , “co2 laser + thermal paste” , etc, with versions of HT wire, ceramic block, multiple types of terms but cant seem to find an answer. Can anybody give me an answer, thank you in advance.
just FYI, i hadn’t used laser in months, and i guess the glue got old and tube was dirty and its now arcing to the frame. I read other posts and watch videos and dont see any damage on any wires and assumed its because this was not making a flat contact to the tube.
RTV cement. Where it was arcing to the frame, there will be a pinhole in the insulation. Put a dab on that too.
thank you pointing me in the right direction. Do you know if there is a particular one? I have used RTV for vehicle stuff and know there are different kinds. I assume the black hi-temp would be ok? Thanks again in advance EDIT: also i had already scrapped off all the old stuff so ill be able to put on a nice clean layer
NO! A thousand times NO!
Common RTV (“Room Temperature Vulcanizing”) silicone caulk cures by releasing acetic acid. Not only is acetic acid corrosive to anything electronic, it is a wonderfully ionic conductor.
Bonus: Silicone caulk, even the fancy platinum cure stuff, is not rated for high voltage applications.
Note that the word “insulation” occurs zero times in the Wikipedia description:
What’s shown in the picture is a splice between two high voltage leads, presumably between the tube and the HV connector on the power supply, that’s been glopped onto the side of the tube, right over the label.
If it is arcing from that splice, then there are more problems in there than you can solve with caulk.
If it is arcing from any other point along the cable, then the cable is defective.
Because a high-voltage electric arc burns through a defect in the insulation and turns it into ash, you cannot re-use that part of the cable: there is effectively no insulation between the center conductor and the outside world.
You’ll find plenty of “insulating” materials, but they must have a rating well above 25-ish kV for this application and must not leave any air gaps. That rules out all tapes, crimp splices, wire nuts, and similar low-voltage components.
There is nothing available to ordinary civilians like us to repair that damage. If the arc was between the tube and the HV connector, you need a new tube.
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its specifically arcing from the ceramic tip where the gob of white glue is. I have a video of it. I had alrady inspected all the wiring and dontt see any burn marks or anything like other peoples pictures. When i discovered it, after reading lots of stuff online, I did read it was possible it can arc because if has a bad connection as the white glue was not holding it down, its was actualyl floating ABOVE the tube because the glue was not holding it on anymore.
I’m still not sure as to what I can use to glue it back down, which is why im here asking.
EDIT:
HERE is link to video. And you cant tell, but the ceramic thing the 2 wires are going into was no longer glued down, there is a gap between it and teh tube.
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I believe lasers are commonly shipped out with something like this:
Electronic Industrial Silicone Rubber Sealing Glue Sealant Adhesive
Based on what you’re saying sounds like this would not be fit for purpose. That’s not comforting.
The arc seems to be emerging from what seems to be the closed end of that “ceramic” splice, in which case the splice housing has cracked and you’re seeing the result of a few tens of kilovolts applied across open air.
The fact the splice block was glued to the tube label is irrelevant; most likely, they stuck it there just to keep it from flopping around. There are no electrical connections inside the tube other than the anode (where one of those red wires goes) and the cathode (the typically thin black wire on the other end).
None of the descriptions have any values for the material’s dielectric strength, typically in kV/mm = Mv/m, which suggests it’s not specified for high voltage applications:
The application method affects the results, with the usual “the bigger the blob, the better the job” smear being a poor way to ensure proper results.
Silicone rated for HV insulation is a thing, but it doesn’t come from Amazon / Walmart / AliExpress.
RTV from Home Depot / Walmart / Amazon (the stuff that smells like vinegar as it cures) is junk for electrical insulation, but it works for low-voltage circuitry in places where you don’t care about corrosion. I’ve made that mistake more times than I care to admit …
Well, THAT got the conversation going! I was referring to RTV, aka as Radio, TeleVision cement.
Everyone is right, even if a bit exaggerating in the consequences. I forgot the adhesives market has shifted.
Insulation ratings are in Volts/mil. An adhesive with 1500v/mill 0.010" thick will give a15KV insulation rating. Automotive ignition systems operate in that range, so look there as a source of approiate materials.
Use nothing with black in it except electrical tape. Black has a lot of carbon in it.
You do not need a lot or dielectric if you keep the wires away from the frame. Just use a semi-flexible glue to allow for differences in thermal expansion. The factory did not make it complicated. Neither should you.
I guess I messed up the math. If an inch is 25.4mm … converting to mm – 0.01" * 25.4mm = 0.254mm
That give a voltage of 0.254 * 1500V = ~384V
Simply, for 15kV insulation, you’d need a layer 10mm thick to make 15kV insulation with 1500v/mm.
Add to that you need protect against 30kV levels, as that’s what the lps can produce.
This arcing can also be caused by a tube failure.
Good luck
I wonder if Clear Electronic Grade Silicone - 2.8 oz Squeeze Tube: Silicone Adhesives: Amazon.com: Industrial & Scientific feom Amazon would work? Supposedly it is electronics rated and non-corrosive. What I didn’t find was a specific rating of insulating power as suggested above. Good news is it is $10/tube. I suspect that the people who think you need a new tube are right. I googled “insulating high temperature glue” and this seemed like the best candidate.
Anyway, if the naysayers are right, you need a new tube, but this will give you a low cost glue to fail with before you buy a new tube assembly. 
Happy new year!
If you look at the specifications, it’s 500V/mm.
Electronics grade only means it works with normal electronics. Once you high voltages then it’s got to be a specific type of silicone formulated for high voltage use.
Common mistake, mil = 0.001", not mm.
Ignoring inches, since these are in mm to start with…
1500V/mm requires 10 times the thickness to reach 15,000V or 10mm.
You’ll have to convince me that 10 times 1500 isn’t 15000… 
Was there supposed to be an argument here or are you just yanking my chain?
I actually did look through product specifications, must have missed that, thanks. Yeah, if this is the only insulation ot is obviously inadequate.
No you’re working in inches (and the specifications), I do things in mm
Most of these seem to be in mm, not inches, so it’s confusing to old people like me.
You’re right, I should be using mils instead of mm.
That’s why we lost a $125 million dollar spacecraft.
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just updating anybody who might care, I did order a tube of some stuff, im willing to try it out before going as drastic as getting a new tube. I’m pretty confident its because it was not glued down and was now closer to the frame. Worst case that happens, I still need to buy new tube and wires and stuff if it doesnt fix it, so I’ll take this chase first. I also attaching a picture of a label I found on the frame, explaing about gluing the thing to the tube.
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I would ditch that connection right away and replace it with these. I used these on my K40 when I replaced a tube…talk about a breeze to apply.
I haven’t had to replace my tube on my 80w yet.
These connectors work great… I have a pair of them.
They fit different wire sizes, so ensure you get the one that works on your wire size.