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Author Topic: Backing for doublets?  (Read 498 times)

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Pusscat

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Backing for doublets?
« on: September 06, 2017, 10:55:04 PM »

Up to now , I've had a bit of a misguided view that I need to stay away from doublets. I have a few bits of thin opal and some thin crystal that actually would probably come alive as doublets.

I don't have much potch and no really dark stuff...

So is there anywhere anyone can suggest I can get a dark potch to use as a backing material for doublets?

Any other suggestions as what to use?  Also any suggestions for varieties of epoxy I should be using that make likelihood of bubbles less?

Cheers, Pete
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bobby1

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Re: Backing for doublets?
« Reply #1 on: September 06, 2017, 11:33:44 PM »

I use Basanite and epoxy 330 to back doublets and triplets. Mix the epoxy on a small sheet of white paper to see if there are any swirl lines in the mix. Mix it under a gooseneck lamp with a fairly high wattage lamp so the mix gets warm. Mix by swirling only, do not "whip" it. Let it sit under the lamp for 30 seconds or so so it will get very liquid and any bubbles will rise to the top.  Using a flat toothpick gently pick up the epoxy and spread a coating on each surface. Drag the toothpick slowly across the surface to remove any excess. Touch the edges of the pieces and close them together like closing a book. The excess epoxy will be pushed out from between without trapping a bubble in between. Gently squeeze the pieces together between your finger and thumb. Move then slightly side to side and continue until the pieces start to drag against each other. Set the assembled piece under the lamp along with the piece of paper with the unused adhesive and let it continue to heat. After a half hour or so turn off the lamp and let the piece set overnight. If you feel that you have to fiddle with the piece to see if it is setting up don't touch the piece. Test the unused adhesive to see how well it is setting up.
Have fun cabbing it.
Bob
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hummingbirdstones

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Re: Backing for doublets?
« Reply #2 on: September 07, 2017, 07:54:15 AM »

There is no reason to stay away from doublets if you have some thin pieces of nice opal.  As Bobby just said, basanite makes a good backing, as does black jade if you don't have black potch.  Black potch is pretty hard to come by these days.  You used to be able to buy it for next to nothing.  Now if you can find it, they sell it by the gram! 

If you can't find a really black stone to use as a backing, a good trick is to paint the back of the opal black.  I've used a flat black paint for painting barbecue grills in the past.  I think Rustoleum made it.  An added bonus to doing this is that it hides any bubbles from the epoxy if you don't get them all out.

As always, make sure you disclose that your opal is a doublet if you sell it.   :icon_sunny:
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Robin

Pusscat

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Re: Backing for doublets?
« Reply #3 on: September 07, 2017, 08:52:05 AM »

Thank for the tips guys!

55fossil

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Re: Backing for doublets?
« Reply #4 on: September 07, 2017, 08:56:15 AM »

    Thousands of opals and other stones are sold in jewelry made just as Bobby described. Once set in Jewelry most people do not even realize if a stone is a doublet or triplet. Yes, they look that done when properly made. I have done this for years and make sure to disclose it.  neal
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Greg Hiller

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Re: Backing for doublets?
« Reply #5 on: September 11, 2017, 01:34:48 PM »

You can always use black obsidian.  Very easy to come by.  While it perhaps chips a little more than basanite it also works just fine.  You can cut it into very thin slabs as well. 
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ASO

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Re: Backing for doublets?
« Reply #7 on: September 12, 2017, 12:18:55 AM »

Find a use for all of your color doublet, triplet, inlay, mosaic, chips in water it all counts.  Black potch is good if you have it I have heaps so that's what I use but allot of people use ironstone because its harder and cheaper and easy to get in bulk.  Spray painting the back side of the opal gives you the cleanest look but in the long run say 100 years I dont know if it will hold up the same as if the epoxy is in direct contact with the opal and the backing.  Another good trick is to add some black oxide powder into the epoxy and yes 330 is the best for now, this is how I make mine.  Use a toothpick or a small paintbrush to work out any air bubbles and follow what bobby 1 said its good advice.  As for a backing I learned a trick from an old timer who spent some time in White Cliffs and what they did back in the day was to take an old record and use that for the backing because you can bang out about 300 per day. good luck 
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