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Let's Rock => Rock Talk => Topic started by: Debbie K on March 30, 2017, 09:08:38 AM
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I want to know what you guys use if you are trying to fill a void with epoxy and how you avoid air bubbles. To date, I have tried HxTal, Devcon 5 minute 2 part epoxy, thick gap-filling superglue, and both thick and thin ultra-violet hardening fiberglass. I am trying to epoxy a piece of opal inside a hollowed out piece of clear quartz. No matter what I do, I either end up with small air bubbles or an odd separation of the opal and epoxy or fiberglass, which I assume is due to shrinkage. I have tried pulling a vacumn, but the epoxy is too thick to release the tiny air bubbles.
I have taken this thing apart about 6-7 times already; sometimes it takes as much as a month for acetone to dissolve whatever I used. I'm just about at my wit's end about what to try next, so suggestions would be greatly appreciated.
Debbie K
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ever tried this stuff?
https://www.amazon.com/Stuff-Thin-Instant-Glue-pieces/dp/B01D3IGAH2/ref=pd_lpo_60_tr_t_3?_encoding=UTF8&psc=1&refRID=X9SCFD6RR1GQMKS25N38
I've used sealers like opticon and hot stuff for opals all the time in the past with good success in no air bubbles. But best results come from heating it.
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I always use epoxy 330. 5 minute epoxy sets too fast. I preheat the two parts to be assembled under a 100 watt lamp. Mix the adhesive on two sheets of white paper so you can see the epoxy as you mix it. Keep mixing until you see no swirl marks in the epoxy. Mix it ONLY with a slow swirling motion so as to not introduce any bubbles. Place the mixed epoxy under the lamp to heat it slightly and make it more fluid as well allowing the bubbles to rise to the top and dissipate. Don't leave it under the heat more than a minute. Pick up a small amount of adhesive on a toothpick and slowly spread it on both surfaces. Do not daub it on the surfaces because you will create bubbles. After the surfaces are coated with adhesive slowly drag the toothpick across the surfaces to remove excess adhesive. As you bring the pieces together touch the edges together and close them together like closing a book.This will avoid trapping air between the surfaces. After they are together press them together between your thub and finger and move them slightly against each other to squeeze out any excess adhesive and any entrapped bubbles. I then place the piece under the lamp while it is curing. I also place the piece of paper with the surplus adhesive under the lamp to use as a test point to see how the adhesive is curing.
Bob
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http://www.ebay.com/itm/UV-WINDSHIELD-REPAIR-RESIN-5-PACK-1-SHOT-CRACK-FILLER-RESIN-TUBE-/191064086935?hash=item2c7c4e9997:g:Kx4AAOSwFqJWk~ev&vxp=mtr
Then after void is filled, apply UV sheet and place in direct sun or under an ultraviolet lamp for awhile to cure
http://www.pdrtool.com/collections/windshield-repair/products/mylar-curing-sheets-made-in-usa
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As a rule I hate any fillers, etc.. But, I think the windshield repair for small pits, etc may be a winner. As long as it is disclosed.
Phish.. Have you tried to test it for hazing or scratching? I am going to have to test this stuff for tiny pits in some Willow Creek I have. thanks..
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i have used it in cracks with a super heated rock (jasper) and one agate i shaped.
I also used it to mend a glass candle tray of my wifes for those little candles in the round tins.
It hides well and i never have bubbles, the ony other way is to put some acetone in 330 epoxy to thin it severely and with heat it gradually fills a void.
The acetone evaporates and then the epoxy hardens over a couple days.
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I've used the acetone with epoxy 330, and use a small toaster oven for preheating the stone(s) and for curing once the mixture is applied. You could always hope for the best, and with a little steady pressure in the applying process you could work out some air pockets, before the curing. Always worked great whenever inlaying turquoise in labradorite.. but opals I wouldn't advise to heating.
While clearing out a house from the passing owners, I picked up a small medical vacuum pump and with a little rigging with a container, I managed to create a vacuum chamber. I haven't had the chance to use it much since it's creation, but the last few projects I did, it worked beyond amazing for removing all the air bubbles in epoxy 330 and opticon solutions. I mainly made it for stabilizing cobbles/slabs, but works well for inlaying and doublets. After the air is removed from said combination, you're free to remove it and cure it in whatever means from there on out.
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Thank you to all of you for your replies. The dilemma is that I am inserting a stone into a hole in a stone and trying to not incorporate air bubbles and it's difficult to do as the stone I am inserting is being encapsulated by the epoxy and other stone on all but one side. Imagine inserting a small glass inside a slightly larger glass and you can see what the difficulties would be.
I tried pulling a vacuum and it caused the epoxy to bubble terribly; the upside was it was apparent it didn't work right away and I was able to clean up the epoxy before it set up. I could give it try like you did by only vacuuming the epoxy, rather than with it assembled.
I didn't try the thin super glue; I'm afraid it will shrink like the thin fiberglass epoxy did and pull away from the stone. I might have to try the 330 or the windshield repair good, as I haven't tried them yet.
My best of the bad was with the Hxtal. If and when I get 'er done I'll post a picture so you guys can see what I was up against.
Debbie K