evang
off to a rocking start
Member since March 2024
Posts: 4
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Post by evang on Mar 4, 2024 0:34:27 GMT -5
I'm hoping to get some advice from people making very high end cabachons for fine jewelry about getting the absolute best possible final polishes on different stones. I do a lot of turquoise and opal, I mostly use picassa blue for turquoise and linde a for opals. I was thinking diamond paste on a hard lap might get a better finish in turquoise with matrixes of a different hardness and prevent undercutting. Also I hoped this might be good for gem silica and malachite, lapis with pyrite etc. any experience or suggestions, maybe a list of what polish is best with each type of stone and why. I'm also looking for experience with hardeners, crack fillers, glues for doublets and backing and for complex or unusual stone setting, inlays, etc. I would like to try more with uv cure epoxy, has anyone used this to stabilize stone like you would with hot stuff? I use opticon starbond and hot stuff, they seam to each have strengths and weaknesses. Thank you for you're time, any help is really appreciated, Evan.
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Post by liveoak on Mar 4, 2024 7:39:49 GMT -5
Welcome to the forum.
You've asked a bunch of questions, I'll take on the first :
For polishing, there is a chart for best polish for different stones :
Patty
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Post by opalpyrexia on Mar 4, 2024 8:18:09 GMT -5
Welcome from Washington, Evan.
I also cut opal and finish it with 50,000 diamond paste. I don't go farther than that simply because a 50k polish is getting pretty close to the resolving limit of optical microscopes. I could see a marketing reason for going to a higher grit, but I don't think it would make an noticeable impact on sales.
I assemble opal doublets with 330 epoxy and always blacken it with a small amount of either carbon black or mars black.
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Post by rockjunquie on Mar 4, 2024 8:34:02 GMT -5
I assemble opal doublets with 330 epoxy and always blacken it with a small amount of either carbon black or mars black. That's interesting, Gary. Is that something you have to disclose or is it industry standard kind of thing? |
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Post by opalpyrexia on Mar 4, 2024 10:28:16 GMT -5
I assemble opal doublets with 330 epoxy and always blacken it with a small amount of either carbon black or mars black. That's interesting, Gary. Is that something you have to disclose or is it industry standard kind of thing?
I wouldn't quite call blackening the epoxy an industry standard, Tela, but it's very common. I've generally not disclosed it online, but I really should mention it. Something like this ought to suffice:
"To maximze the brightness of the opal layer, it has been backed with <black jade, black jasper, ...> and cemented with black epoxy."
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Post by hummingbirdstones on Mar 4, 2024 10:28:46 GMT -5
I assemble opal doublets with 330 epoxy and always blacken it with a small amount of either carbon black or mars black. That's interesting, Gary. Is that something you have to disclose or is it industry standard kind of thing? Tela, it's standard practice for opal doublets. You always want to back an opal with a black backing because it makes the colors pop. I used to use black opal potch for my backings, but that has become hard to find now and if you can find it, it's stupid expensive for just black potch. Likewise, if you're doing inlay, you want the inside of the setting you inlay in to also be black for the same reason. |
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Post by rockjunquie on Mar 4, 2024 11:03:49 GMT -5
That's interesting, Gary. Is that something you have to disclose or is it industry standard kind of thing?
I wouldn't quite call blackening the epoxy an industry standard, Tela, but it's very common. I've generally not disclosed it online, but I really should mention it. Something like this ought to suffice:
"To maximze the brightness of the opal layer, it has been backed with <black jade, black jasper, ...> and cemented with black epoxy."
That's interesting, Gary. Is that something you have to disclose or is it industry standard kind of thing? Tela, it's standard practice for opal doublets. You always want to back an opal with a black backing because it makes the colors pop. I used to use black opal potch for my backings, but that has become hard to find now and if you can find it, it's stupid expensive for just black potch. Likewise, if you're doing inlay, you want the inside of the setting you inlay in to also be black for the same reason. Thanks! I have seen the black doublets and I knew about darkened cups, but I have never seen it actually stated. That's why I wondered. |
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johnthor1963
starting to spend too much on rocks
Cattle dogs rock
Member since June 2023
Posts: 236
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Post by johnthor1963 on Mar 4, 2024 16:42:35 GMT -5
Welcome from Indiana
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Post by hummingbirdstones on Mar 4, 2024 23:27:40 GMT -5
That's interesting, Gary. Is that something you have to disclose or is it industry standard kind of thing?
I wouldn't quite call blackening the epoxy an industry standard, Tela, but it's very common. I've generally not disclosed it online, but I really should mention it. Something like this ought to suffice:
"To maximze the brightness of the opal layer, it has been backed with <black jade, black jasper, ...> and cemented with black epoxy."
Gary, that's actually perfect wording. I am going to steal it if you don't mind.  |
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evang
off to a rocking start
Member since March 2024
Posts: 4
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Post by evang on Mar 17, 2024 17:19:10 GMT -5
Sorry it took a bit to get back here, lost my username and password! Thank you all for your advice! Gary, what kind wheel are you putting the diamond paste on? I was thinking leather, does this work well for boulder opal with a softer matrix. Also i need some recomendations on saw blades for splitting opal and turquoise, 4 and 8 inch. I have some chinese blades that are very thin and cut great but they are impossible to keep straight and control, not good for really high end material. Also anyone with experience on final polishes for a variety of turquoise? Ive had the most trouble with some natural royston, very soft but real beautiful material.Also when the turquoise is especially gemmy i'm often getting a matte finish in matrix when i polish with picassa, and it undercuts some of the spiderwebbing. Thanks, Evan In California.
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evang
off to a rocking start
Member since March 2024
Posts: 4
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Post by evang on Mar 17, 2024 17:43:13 GMT -5
Also does anyone have experience working with uv glue and inlays, intarsia? Is it string enough to prevent lifting of metal band when cutting an intarsia cab, what about optical adhesive?
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Post by opalpyrexia on Mar 17, 2024 22:21:22 GMT -5
Sorry it took a bit to get back here, lost my username and password! Thank you all for your advice! Gary, what kind wheel are you putting the diamond paste on? I was thinking leather, does this work well for boulder opal with a softer matrix. Also i need some recomendations on saw blades for splitting opal and turquoise, 4 and 8 inch. I have some chinese blades that are very thin and cut great but they are impossible to keep straight and control, not good for really high end material. Also anyone with experience on final polishes for a variety of turquoise? Ive had the most trouble with some natural royston, very soft but real beautiful material.Also when the turquoise is especially gemmy i'm often getting a matte finish in matrix when i polish with picassa, and it undercuts some of the spiderwebbing. Thanks, Evan In California.
For my 50,000 grit final polish I use this dedicated compact polisher that I built. It has a cushioned cloth pad (photo taken when new, obviously). I think leather would work, but think I recall reading somewhere that polishing on leather can get pretty hot if you're not careful.
I can't help with turquoise; I've never worked it.
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evang
off to a rocking start
Member since March 2024
Posts: 4
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Post by evang on Mar 17, 2024 22:54:18 GMT -5
Beautiful polisher, thanks Gary! Is that muslin and foam rubber backing? I'm thinking I will either build a dedicated polisher with different wheels or have some wheels I can throw on my faceter. Any preferred saw blades for cutting opal doublets?
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Post by opalpyrexia on Mar 18, 2024 16:40:54 GMT -5
Beautiful polisher, thanks Gary! Is that muslin and foam rubber backing? I'm thinking I will either build a dedicated polisher with different wheels or have some wheels I can throw on my faceter. Any preferred saw blades for cutting opal doublets? Yes, the pad is probably muslin and it does have a foam rubber back.
As for saw blades to make opal doublets, I assume that you are referring to sawing opal rather than sawing backing material. The only saw that I use on opal is my Ameritool trim saw with 5" blades. I will sometimes trim a piece of rough on the saw, but I never try to get close to the fire. Exposing fire (or just getting close to it) is best left to the flat lap prior to heading to polisher wheels.
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Post by vegasjames on Mar 18, 2024 16:57:55 GMT -5
Welcome Evan from Southern Nevada.
I bought some UV glue while searching for UV epoxy. Come to find out that the UV glue I bought was not epoxy at all, but rather I think it was acrylic. And when I opened the bottle it was already hard.
These glues are also not as hard or strong as epoxy.
I would go with a high end epoxy and make sure the back of the stone where and the base you are setting it on are both roughed up some to increase surface area for extra holding power.
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