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Prong Repair

I set a Tiger Eye stone and after pushing the Sterling prongs into place I discovered the ends of the prongs were very sharp…I filed too much. What is the best way to round off the prongs without having to remove the stone. I do not want to scratch the stone and don’t know what to use to solve the problem.

How do I describe this? I hope this makes sense. I was recently trying to instruct another local setter on this technique, and I am not sure how best to teach this, if not in person.
At Bowman Tech, over 40 years ago, I crafted this prong finishing tool from @3mm square steel stock, in a graver handle. Shaped, hardened, and tempered.
I can “burnish” down the very tip of a sharp prong with this tool, until the metal touches the surface of the gemstone. V prongs, round prongs, any prong can be worked down, with care.
I start by supporting the prong into a groove in my bench pin, and then using the nearly chissel point on this tool, I “catch” just the sharp tip of the prong, and putting all my pressure back against the metal, and NOT down toward the stone, I rock this tool around the tip of the prong.
This gradually burnishes the sharp area, and closes the gap between the stone and the crown or surface of the gemstone.
This removes no metal at all, but works the very sharp edge of the prong down.
One surface of my tool flat and highly polished, and this surface is what touches the prong. The other side of this “chissle point” is cut away with stacked cut-off discs, to give a concave surface, so my tool never actually touches the gemstone.
It takes a lot of practice, but this tool can solve a multitude of difficult setting problems, and close gaps that no other tool I know can solve.


I am looking at the images I just posted and realize I need to retouch that tool.
Still, after 40+ years of use, this original tool I crafted in 75 is still my fall back for saving prong problems, combined with another prong undercutting tool of my own design.
With my aging eyes, using these tools now requires working under the Mejji, setting scope, but that was not always the case.


Thank you so much for taking the time to write such a detailed description and including photos of your tool. This gives me some ideas of what I may be able to do with tools I presently have. I was looking at it totally from a filing point of view.