What kind of glue keeps clear epoxy resin from yellowing?

I noticed that every time I use super glue to paste a picture down. Let it dry and then coat with the epoxy resin...the resin turns really yellow. I notice that it will do that with fast drying glues....





Do you know what is in the super glue that makes it do that? And what kind of fast drying glue will keep the resin from yellowing?





Thanks in advance. :)What kind of glue keeps clear epoxy resin from yellowing?
First, two-part *polyester* resins themselves (also called ';casting'; resins, like Cast 'N Craft) won't yellow as easily as hard-surface epoxy resins will (Envirotex Lite, etc.), but they'll both do it --especially over time from too much UV light, or from too high a heat while wet or while curing (try for 65-75 degrees), or even afterward if heated too high.


Also, *epoxy* resins can yellow (or ';amber';) just if they're more than 1/2'; in total thickness (...they can be poured no more than 1/8'; at a time).





You could try using Varathane (Diamond Elite, Gloss, water-washup --an acrylic finish for bare wood) instead if you're using only a thin layer of clear resin since Varathane has a UV protectant in it and acrylic finishes can also take some heat after curing.








As for gluing items down before adding resin, usually a permanent ';white glue'; is used ---but it can be a really *thin* coat (rub most off with finger), or even just a tiny dot or two, to speed up drying time ...those applications shouldn't take long to dry especially if they're in a reasonably warm area, or where there's some air circulation.


....Some papers and other porous materials require sealing with diluted white glue (4 to 1 water to glue) then drying so they won't become transparent when the resin is added or create extra air bubbles though... when you add the little bits of glue to those the backs of those surfaces, they might take a tad longer to dry --don't know.





You could also try holding the pictures down with a bit of ';spray adhesive'; on the back of the paper and see what happened, I guess.


I don't know why instant glues would cause the resin to yellow by themselves though, but probably have some chemical in them that reacts with the resin (unlike white glues would).





There's more info on both epoxy and polyester resins, and how to use them in various ways for casting in bottle tops, or for coating, etc., on this page of my site if you want to check it out:


http://glassattic.com/polymer/other_mate鈥?/a>








Diane B.What kind of glue keeps clear epoxy resin from yellowing?
The owner of an epoxy products company told me a while ago that all clear epoxy putties will eventually yellow. I know that superglue and epoxy glue can influence eachother and to me it sounds like the superglue is accelerating the yellowing process.





Have you tried leaving the superglue a few days alone before applying the epoxy?





What is the reason for the epoxy by the way? Are you making something like a ';glass'; cover for the picture? Like you sometimes see with pendants? If you are only using the superglue to keep the picture in place while you are applying epoxy you could also experiment with other glues. For instance elmers (roughen the surface you apply it too) or a rubber glue.





Diane: that's a great website you have there!