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Rock Art => Cabochons, Intarsias, Cameos => Topic started by: mdfa.ca on October 28, 2016, 11:12:43 AM

Title: Resizing a tiny cab
Post by: mdfa.ca on October 28, 2016, 11:12:43 AM

Quick question for you guys:  I'm making my first cab ring (sterling silver) for my son's girlfriend's birthday. The stone is a round 5mm opal triplet. I'm ready to set the stone but there is one little problem:  it's a bit too tall so the bezel won't hold it. I need to shave a bit off the bottom. Is there an easy way to do this? This stone is so tiny and slippery, I can't do it with my hands. And since it's a triplet, the bottom is pretty hard, too. Do I absolutely have to dop it or is there an easier / faster way to do it?

Title: Re: Resizing a tiny cab
Post by: gemfeller on October 28, 2016, 02:18:02 PM

Dopping is probably the easiest way to do it though some experienced cutters probably wouldn't need to.  Since it's a triplet I'd recommend cold-dopping because heat could affect the triplet's adhesive bonds.  Use a drop of Elmer's or carpenter's glue for dopping and let it cure overnight.  I brush on a coating of clear nail polish after the glue has cured to make sure the water-soluble glue doesn't weaken from the water used in grinding.  The dop will also help in getting the stone out of the setting when you're testing the height adjustment.  When done simply scrape the nail polish off and immerse the stone/dop in water for a few hours.  It should release easily.     

Title: Re: Resizing a tiny cab
Post by: mdfa.ca on October 29, 2016, 07:27:57 AM

Gemfeller,  excellent advice, thank you! I'll keep it for next time. The reasons you listed for not hot doping were the exact fears I had. Now I feel validated  :LOLOL:

In the end I used my small needle nose pliers with the acrylic coating and basically shaved the bottom off on a piece of sand paper with water. Slow, fiddly and hand cramping procedure, but it worked. Here is the finished ring:

Title: Re: Resizing a tiny cab
Post by: mdfa.ca on October 29, 2016, 07:28:48 AM

Hey, where did my other 2 photos go?  Here is the best one:

Title: Re: Resizing a tiny cab
Post by: gemfeller on October 29, 2016, 07:49:27 AM

Nice job!  Often in this work you have to improvise with the tools you have.  I was going to suggest hand-sanding the excess away but, depending on the amount, it could turn into a very tedious process.  That's where tools like the Foredom flex shaft with "heatless" Mizzy wheels can be invaluable.   

Title: Re: Resizing a tiny cab
Post by: mdfa.ca on October 29, 2016, 07:52:55 AM

Thanks, Gemfeller, and indeed. I'm saving for a foredom flex shaft...

Title: Re: Resizing a tiny cab
Post by: Phishisgroovin on November 13, 2016, 07:47:42 PM

VERY NICE!!!!!!
I love making these simple rings with tiny stones i hand shaped on files, sand paper and hand polish.

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Title: Re: Resizing a tiny cab
Post by: gjones on November 14, 2016, 05:00:58 PM

Excellent work you guys!!!!    :hello2: :hello2: :hello2: