UV resin - share your experience

Recently I’m trying to find suitable resin for my mods but there are unanswered questions which I’d rather consider before the purchase.

Maybe some of you know:

  1. does it conduct electricity?
  2. does it conduct heat?
  3. does the thermal expansion coefficient is close to the one of aluminium?
  4. which UV wavelenght hardens it deepest?
  5. can it be used for potting driver?
  6. any other hints or warnings that I’m not aware of?

Question 3 refers to the risk of cracking in freezing temperatures when expansion of aluminum is different than expansion of the resin.

What are you asking about? Any particular brand in mind?

These are general questions.

A particular brand could not be available at my country thus I’m asking for your advices.

Are you talking about UV resins that are sold for projects that are used for Boats? 3D printers, as UV protectant?

Your question reads like what is your recommendation for samich bread. There are so many different types that are used for different project types.

Unfortunately we just need more information in what you plan on doing with said resin.

Sorry. I didn’t realise these may vary that much.

Typical applications I’m thinking about are:

  • fixing driver to the pill
  • making a washer for uncommon reflector hole
  • potting the driver
  • holding mcpcb in place when it has room for movement

I have used some recently, but not for anything like you want it for sadly.
I used one of those UV nail curing units from ebay (like a dome with numerous uv led’s in it), cost about £5.

What I did was put alumium foil under it and over the front to intensify the uv and reflect it back inside.
It works fine, but, as I’ve found out is a common problem it stays sticky almost oily for a few days, but eventually that goes away. I was making custom keys for a keybord, or at least playing with it. Worked fine and gave good results, no shrinkage compared to normal resin (so I’ve read) less issues with bubbles either as you don’t have to mix it up.
I saw on a youtube video the sticky finish is reduced if you expose the part in water after initial hardening - but like I said, left a few days in a sunny window it dries out fine with no tackyness.
I would imagine it would tick all your boxes, and it is relatively cheap from aliexpress if you wanted to try it.
Finally, if you are making a mold, it really needs to be clear, to let the uv through.

Very helpful hints, I’ll try it out. Thank you. :man_bowing:

1 thru 3 NO.
4- 400nm seems to be the range they recommend, but i used 365 successfully.
it is useful to fill gaps, its adhesive qualities are not that great, you could make shapes with it too. some is pretty strong.

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Super Bad Choice for all of those purposes.

All LEDS make a few things in addition to light. most make a bit of UV, that makes the resin more brittle over time, Clear resin will turn yellow over time. Heat destroys resin again over time. So the first three are defiantly bad ideas.

There is a reason back in the 2004-2016 people would use lead based foil tape, gobs of soder, or hand file washers to make things fit. Heat destroys things. you need a material that is a good heat sink and still good strength and ability to be machined. If I remember correctly Copper is a popular material that you might want to look in to for lights. is relatively affordable and easy to shape with hand tools. it also as great thermal qualities.

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I’ve used a decent amount of UV cure resin and have a couple answers to your questions:

  1. It’s nonconductive at low voltages, I wouldn’t trust it with mains unless it was rated for it.
  2. It’s essentially acrylic so not very thermally conductive (still better than air)
  3. No idea
  4. Most say a 405nm source but it hardens extremely quickly with the 365nm of my S12 UV
  5. Not really, it’s much to brittle to even be used as a conformal coat.
  6. Plastic monomers are extremely toxic so make sure to handle it in a well ventilated area and would strongly recommend gloves.

I haven’t tested this resin at low temps but I know it gets a bit soft (but doesn’t melt or permanently deform) at soldering temps

imo UV resin is primarily intended for setting tritium vials on the outside of a light, because the resin is very translucent.

I think you would be better served by Thermal Epoxy, just note it gets very hard and is not removable.

can it be used for potting driver?

I dont think so.

You could use Thermal Epoxy, or you might find a Conformal Coating to be more convenient, as is used in Zebralights. It is like silicone, and can be peeled off.

Thank you. I owe you man :beers:. Very happy with your answers.

I’ve bought GItD powder recently so I’m still having plans to play with it.

Oh yeah mixing that will creat some really cool GITD resin, make sure it’s a paste consistency and it takes way longer to cure

UV resin is pretty bad choice for mounting trits, it does not stick well, you only need a little of epoxy on the underside, not over the vile, clear 2 parts epoxy works pretty good for that purpose, To cure resin fully you need to illuminate it with uv from all sides.

You pretty much rely on the cured resin’s friction with the milled sides of the slots to hold it in which is more than adequate for a trit, but if you shove a tiny bit of foil behind the vial before adding the resin it could help reflect some of the UV back out.

Why? there is already perfectly workable solution, 2 parts clear epoxy. why reinvent the wheel, especially when perfectly good wheels are commonly available?

Trits don’t last forever. Epoxy is not easily removed like other adhesives afaik.

Cyanoacrylate can be removed with acetone. NOA61 UV adhesive can be removed with methylene chloride paint stripper, or heat, or a needle or exacto blade, or a combination of those things.

If you need it done quickly I guess the resin is better since it cures completely in minutes.

Well if you wanted to get it done quick then yea, but if you want to get it done right, with no mess, and reliable hold for as long as trits last, I would use 2 parts epoxy.
It is true that epoxy is not as easy to remove as other glues, but that is why i would want it. lights get dropped, with weak glue trits will likely fall out.

Using two part epoxy would be a permanent solution. Non-removable.