# Epoxy/Resin over clear silicone caulk



## TZH (Oct 20, 2009)

Does anyone have any experience using epoxy/resin over a layer of clear, fully cured silicone caulk being used as a "filler" of sorts? I have an upcoming project that has me stumped. The piece I'm working on has a hole in it similar to this one:










The hole in the piece I'll be working on is a little irregular in shape and goes from the front of the piece all the way through the piece and out the bottom (does not go through the back, so I can't lay the piece down on its back to pour in the epoxy without it running all over the place). I don't want to fill the entire hole because it's intended to become a lamp sculpture Christmas gift for my wife. The hole will be filled with crystals of different colors with the lamp light bulb at the bottom of the hole shining up and through the crystals. I only want to do one layer of crystals about one inch thick, and am considering using clear, fully cured silicone to attach the crystals in stages until the hole opening (not the entire chute) is completely filled. The crystal/silicone combination would then essentially become a "backer" for the epoxy/resin to cover. I would then pour over the entire piece with epoxy/resin to complete the project. My concern is whether or not the epoxy/resin is compatible with the silicone caulk. I'd let the caulk fully cure before trying anything with the epoxy/resin. Flexibility of the silicone wouldn't be an issue because there would never be any pressure placed on the crystal hole filler.

Hope this makes sense. Thanks for looking, and thanks for any feedback you might be willing to share.

TZH


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## shipwright (Sep 27, 2010)

The epoxy won't be affected by the presence of the silicone but it won't stick to it either. If the epoxy has enough clean crystal surface area to adhere to it should form a skin over the whole (hole?) and if not stressed the skin should stay intact. Any large areas of silicone exposed may cause the epoxy to 'fish eye" and withdraw from that area but I don't think that you will have that as I understand your plan.

My question is why don't you eliminate the whole concern by applying the crystals with epoxy in the first place?
In my mind it would be a much stronger, better fix .


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## TZH (Oct 20, 2009)

Hey, shipwright. Thanks for the feedback. I think you answered my question by saying the epoxy won't stick to the silicone. I guess my hesitation in using epoxy was because I'm going to have to "build" the crystal "plug" step by step and it'll take an awfully long time, I think, for the epoxy to set with each application. I was just trying to find an easier way, but am probably going to have to just bite the bullet and do it the right way. Thanks, again.

TZH


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## shipwright (Sep 27, 2010)

You can use five minute epoxy for that. It's not that strong but you don't need strength. Then use a good epoxy to do the finish.


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