Although some brands of resin claim they don’t yellow, it’s a well-known hazard. Following is my test of what happens when sample tiles of eleven brands are left on a sunny windowsill with their top halves protected.
The photo above is before the yellowing test began. The cured EnviroTex Lite and EnviroTex had already begun to yellow over a period of 19 months in a covered cardboard box in my windowless basement.
The brands used were:
- Alumilite Amazing Clear Cast
- Art Resin
- Cernit Kit Finish Glass
- Chinese resin from Amazon (brand unknown) – UV
- Pandora Deep Shine – UV
- EnviroTex Jewelry Resin
- EnviroTex Lite Pour-On High Gloss Finish
- Ice Resin Jeweler’s Grade
- Little Windows
- Lisa Pavelka’s Magic Glos – UV
- Resin Obsession
- UltraDome UV Epoxy – UV
There are four UV resins. The rest are two-part, epoxy resins. The resin caused my handwriting to melt on some of the tiles.
I covered the top halves of the tiles with double-faced foam tape. This really stuck to some of the resins and made quite a mess, so I’ll try aluminum foil next.
I’ll keep a close eye on this test and shoot photos fairly frequently.
Sun exposure begins
The above photo was after only four hours in full sun. I put the tiles in order of visible change with the worst in the top left.
The Chinese resin was thick and sticky when I used it and wouldn’t self-level. Apparently, I got a bad bottle. When I removed the foam tape, it came off of the polymer like a piece of cellophane, but I’ll include it anyway.
I removed the leftover adhesive which was making a dirty horizontal line in the center of the tiles. The bright yellow of Cernit Kit and Ice Resin has faded a bit, maybe bleached out by the sun? Amazing Clear now looks clear again. I can see a very slight difference in Magic Glos, Deep Shine and UltraDome.
The yellow in EnviroTex Lite seems the same. The yellow is fading in EnviroTex Jewelry, Cernit Kit and especially Ice Resin. The very slight color change in Magic Glos, Deep Shine and UltraDome remains. Amazing Clear, Resin Obesession, Little Windows, Art Resin and the Chinese Resin are clear.
I moved Resin Obsession to the top row because it seems to be turning yellow overall, maybe from heat, rather than UV rays. Cernit Art, Magic Glos and UltraDome all seem to have the same slight yellowness on the bottom half. The bottom row seems pretty clear.
Resin Obsession is getting more yellow overall. Little Windows might be turning color a bit overall. The bottom halves of Magic Glos and UltraDome seem slightly more yellow.
Little Windows has started to yellow overall. Magic Glos and UltraDome seem a little more yellow on their bottom halves.
The most noticeable difference is Little Windows which yellowed more. The rest look about the same.
Little Windows is now more yellow than Resin Obsession. Magic Glos has yellowed a bit more.
Not much change, except Magic Glos looks darker yellow than EnviroTex now.
The yellow of EnviroTex Lite and Little Windows seems more intense.
Little Windows, Magic Glos and UltraDome seem a little more yellow.
UltraDome might have yellowed slightly more.
I can’t see any difference after another 50 hours in the sun.
The yellow in Envirotex seems to be fading. The rest appear the same.
I can’t see any difference. I wonder if they’ve stabilized.
Not much difference since the last photo. Amazing Clear Cast might have gained a tiny, little bit of color. Little Windows seems lighter.
It’s been 8 months since I last posted a photo. A few resins have gotten darker. None have improved by the sun bleaching them. Art Resin is still looking really good. It’s now the brand I choose when I use resin.