Opal Cutting, Treatments & Commentaries

May 11 2017Welo Opal & Dopping Glues

BTW, I meant to send you a couple of tips on how best to use that Beacon 527 glue I told you about:

I gently mash a roll of modeling clay onto my workbench, and then (balancing carefully) use just a drop or two of the glue to initially attach the dopstick to the stone … then stick the bare end of the dopstick upright into the clay to hold it upright. If I use more than a drop or two in this step, it runs down the dipstick.

Once the glue is at least partially set (a couple of hours, max), I then turn the dopstick stone-side-down, and (using a toothpick), spread a little more of the glue where stick meets stone … then I press the top surface of the stone into the clay (bare stick-side-up), and let it cure overnight before smoothing & polishing.

I used a very similar technique for the Elmer’s method you recommend … as you’ve no doubt discovered for yourself, just a drop or two of either glue won’t be enough to form a strong-enough bond between stick & stone.

Lindsay Koob

  1. vsoadmin Post author|

    Secondly, I’ve FINALLY gotten my lapidary workshop set up & running in my new home … after some trial-and-error as to where I should put it! I’ve also upgraded my equipment (variations on the flat-lap-based High-Tech Diamond brand) — i.e., I now have new “smoothing” discs in four grits (325, 600, 1,200 and 3,000), all backed with thin rubber foam pads to minimize “flat spots” and facilitate doming.

    I’ve also found that a 600-grit grinding lap is quite sufficient for basic shaping of stones (unless you want to quickly grind away sand or potch layers) — and it leaves relatively smooth and scratch-free stone surfaces that are much easier (and faster!) to smooth out and polish.

    Speaking of polishing, the Hi-Tech setup uses felt pads (also foam-backed) that you charge with diamond polishing compound (I use 14,000 and 50,000 grits) — and it’s a strictly DRY polishing procedure (though you have to be careful to avoid undue heat buildup).

    FYI, I’m still using the “damp” smoothing and polishing technique (neither wet nor dry) that I described to you earlier: namely using a sponge (or a VERY slow water drip setup) to keep the smoothing disc just barely wet. It eliminates the dry-cutting rock dust problem AND minimizes water absorption into the hydroplane stones.

    I’m also experimenting with dopping my stones with “Beacon 527” glue: it holds the stones very tenaciously, and requires only a brief soak in acetone (outdoors!) to remove them after cutting. Interestingly, the acetone also soaks into the stones, and causes the stones to lose color like water does … BUT they dry out MUCH more quickly, and don’t dim the play of color or damage the stone in any way. I haven’t tried it on my larger A – to – AAA-grade stones yet — but it works very nicely with smaller stones. It also seems to minimize the cracks that often show up when you soak the stones in water.
    Lindsay Koob



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