Has anyone ever experimented with UV activated epoxy?

[Mad Hatter]

I am hemi-plexic due to a stroke I had 2 years ago and I have a difficult time working with epoxy anymore. It ether sets up too fast or it doesn't set at all. I worked at a printing plant for several months that used UV activated ink. It would be sticky till you walked out the door into the sunlight then it would set. No oxyclean or bleach could take it off! Thanks Ken

[NativePaul]

Oops.

[NativePaul]

I used to be a printer too, printing the writing and pictures on the tops of CDs and DVDs using UV curing ink, we used a lot of UV curing epoxy in the factory as a DVD is 2 sheets of polycarbonate with a metalised layer in between and the 2 layers are glued together with it, and a CD is only a single layer of polycarboanate but the metalised surface is given a thin epoxy coating to give it some semblance of scratch protection. It was pretty good stuff achieving full cure in under 1/3rd of a second under a 1.5KW UV light, whilst being spun to flatten the surface and remove excess resin.

As good as it was I never bothered to take any home as I rarely have to glue anything transparent, and if at least one of the surfaces you are gluing is not transparent you will only be able to cure the edges and the bulk of the epoxy inside the joint will never cure.

You might consider using a laminating/finishing/skinning epoxy instead of an epoxy glue with a slow curing hardener, some of them offer up to an hour of pot life before they start gelling giving you way more working time that any epoxy glue will, and as long as you mix them to the stated ratio (by weight useing little 0.1g drug dealer type scales is the best for small quantities as you would typically use when gluing) will always cure nice and hard, typically it is thinner than an epoxy glue, which can be a good or a bad thing but if you want it thick, you can thicken up to a filler or anywhere in between by mixing microballoons, coloidal silica, milled glass, milled carbon, aluminium powder, iron filings or talcum powder into the resin as you stir the 2 parts together. The down side is also the upside, it takes a long time to cure, 6+hours to harden and full strength is 24hours+.

[pescador]

I use UV resin to tie fishing flies, it has pretty much replaced two part epoxy. It comes in various thicknesses and a flexible version, I have an old uv light from a dentist I use to set it but they sell flashlight type uv lights as well.
I think the cost would be considerable for a boat build except for small jobs, unless you could source the resin in larger quantities for cheaper.


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[fweasel]

I used to be a printer too, printing the writing and pictures on the tops of CDs and DVDs using UV curing ink, we used a lot of UV curing epoxy in the factory as a DVD is 2 sheets of polycarbonate with a metalised layer in between and the 2 layers are glued together with it, and a CD is only a single layer of polycarboanate but the metalised surface is given a thin epoxy coating to give it some semblance of scratch protection. It was pretty good stuff achieving full cure in under 1/3rd of a second under a 1.5KW UV light, whilst being spun to flatten the surface and remove excess resin.

Funny story, my first job out of college was as a chemist in a lab formulating those polymers for the DVD manufacturing industry as well as the primary and secondary coatings on optical fiber.

[Mad Hatter]

Much thanks to all. I am a firm believer in UV. My first experience with it was with a fish pond i built around 30 years ago,no matter what I did to it,it always turned into pea soup, I added a UV filter, end of story. It was crystal clear within 12 hours! I now use UV shoe sanitizers to help with my my toenail fungus. It's working great! Just don't look at it, it'll burn your retinas and corneas out. I'll look into it,much thanks again to all for your input and support. -Ken-

[srislash]

Much thanks to all. I am a firm believer in UV. My first experience with it was with a fish pond i built around 30 years ago,no matter what I did to it,it always turned into pea soup, I added a UV filter, end of story. It was crystal clear within 12 hours! I now use UV shoe sanitizers to help with my my toenail fungus. It's working great! Just don't look at it, it'll burn your retinas and corneas out. I'll look into it,much thanks again to all for your input and support. -Ken-

Now this is interesting. I need to look into this while the issue is small(toenails).

[Mad Hatter]

Thanks a bunch Shawn, I realize that this forum is not about fish ponds or toenail fungus, but about boat building. I would love to find a solution to this problem I'm having with epoxy. It either takes 72 hours to harden or it starts setting while I'm working with it. I helped my friend build several ice boats years back. You being from BC might know what this is about. We used the ''West System", It worked great, but I'm working with small quantities. Help me find a solution please. -Ken-

[NativePaul]

This sort of thing makes working with small quantaties of laminating resin like west systems easy, and and reduces waste.
Digital gram scales

West systems do have fast and slow hardeners, but their slow is still pretty fast compared to the slows of many other epoxies, its middlingness may be just what you are after, or not.

[pescador]

I also use West Systems with their pump dispensers, I’ve always used 205 “fast” hardener and it’s usually dry overnight. I have some 206 “slow” but I’ve never had to use it.
But for small batches I use West Systems GFlex and a set of digital scales mentioned above. You can measure tiny batches and GFlex has an advertised 75 minute working time.


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[srislash]

Well I am using System Three. They have a Pkg which is named ‘Cold Cure’ , I think it is a 500ml epoxy and 250l hardener. This is what I used when I started this work. Now I buy larger quantities of ‘laminating resin’. For my small quantity jobs or for tacking I have syringes with epoxy in one and hardener in the other. Then I can dispense by the ‘cc’.
Both aforementioned products are ‘24hr’ but overnight or 7-8hrs is good to remove clamps blah blah.

I have a moderately temperature controlled room (hobby boat room) so don’t have many issues with cure times but... in the past it has taken quite awhile to cure when it’s been a cold environment.

BTW, bigger jobs get the digital scale method of mixing.

[Mad Hatter]

This seems to be a hot topic. I'm glad I've seem to have gotten us all on the same page.i think panchothedog, may have some input so I'll stand by.