Griff
(Well crap, my hypometric precursor device is blown…)
1
I see all the nice epoxy projects here in the forum and elsewhere. I can think of a few I might like to do myself. But my experiences back in the last century always come back to dissuade me.
Projects yellowing with age. Maybe not such a concern in todays disposable age?
For Christmas money back in my Navy days my wife painted plaster pieces with acrylic paint and I epoxied them for protection and appearance. I also made “hippie” furniture out of wooden wire spools and 2x10 construction lumber. Distressed with chains and hammers, burned and wire brushed, placed coins, dried flowers, bits of this and that in the deeper distressed areas. Epoxied the result.
All the pieces yellowed within 5 years or so. Especially disappointing for the artsy pieces my wife spent hours painting. None were exposed to direct sunlight.
So, any truly non-yellowing epoxies out there? I mean from experience, not what is claimed on the container.
Science has come a long way since the last century and that includes epoxies. I don’t have anything I can recommend as the stuff we use in the stone industry is not the same as the pour epoxies being used in woodworking projects (most of the stuff we use is a knife grade/gel as opposed to a flowing). I would talk to the guys at PlastiCare for info on non-yellowing pour (flowing) epoxies.
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Griff
(Well crap, my hypometric precursor device is blown…)
3
Science has indeed come a long way. But…
Epoxy resin in the ‘60’s/70’s consisted of monomeric resin, hardener,
accelerator and plasticizer.
Epoxy resin today consists of… monomeric resin, hardener,
accelerator and plasticizer. So I wonder what’s changed?
I’ve sent the question to the folks in the link you provided, we’ll see what the say.
I used Magic Resin for my recent project. It claims to have UV protection and ‘resists yellowing’. Time will tell if it’s true, but the current products have been on the market long enough that someone should have an opinion about their claims. Youtube or crafting forums dedicated to epoxy would have the best info.
Ha ha, that sounds like saying a car tire in the 60’s/70’s contained rubber. Today a car tire contains rubber I’m no chemist, but rubber compounds used in tires today are nothing like the rubber compounds used in the 60’s/70’s… Again, not a chemist, so couldn’t tell you exactly what changed, but hands down I know there are differences.
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Griff
(Well crap, my hypometric precursor device is blown…)
6
From the folks at Plasticare:
The hardener for the epoxy does yellow over time and from UV exposure in liquid form. Once it is hardened it will only yellow from UV exposure.
One of the main differences through technology over the decades appears in part to be newer UV protective additives in the epoxy formulations. So countertops, bar tops, crafted pieces, boat decks, don’t yellow nearly as much as they used to.
Two other factors that may minimize the effects are that I mostly use colored epoxy. With pigments and dyes to where it is a full color all the way through. In this case, yellowing wouldn’t really affect it as much since visually the difference would be minimal. The second is that I’ve heard mention of coating a final clear epoxy layer with a UV resistant polyurethane topcoat. It is supposed to block and UV and oxidation.
I am sorry to hear about your wife’s art. That is terrible. So much is poured into painting, not least of all, time. All the stuff you did too. I wonder if there is some sort of fix or method.
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Griff
(Well crap, my hypometric precursor device is blown…)
10
Not to be combative, but the 4 direct manufacturers of epoxy I’ve recently contacted have all stated their product will eventually yellow due to UV. So, I’ve answered my own question😊.
I suppose it’s possible for a third party reseller to add some sort of magic UV inhibitor but I’m skeptical.
Good point, I’ll keep that in mind.
Tried that in 2017, direct sun exposure to be sure plus heat and smoke.
Griff
(Well crap, my hypometric precursor device is blown…)
11
Me too, thanks for the sympathy.
Many of her pieces are scattered throughout the family and still in use every Christmas. All are yellowed, none exposed to direct UV. Plus, as you might imagine, stored in dark boxes 11 months of the year.
A good way to avoid the yellowing of epoxy is to add a little bit of dye to epoxy - blue dye works very well. Epoxy is still translucent and looks more like glass and doesn’t go yellow over time.
I’m no chemist, but rubber compounds used in tires today are nothing like the rubber compounds used in the 60’s/70’s… Again, not a chemist, so couldn’t tell you exactly what changed, but hands down I know there are differences. 
