Laser Welded
Rose Gold Micro Bezel
by Steve Satow
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1. One of our wholesale customers requested we flush set a customers’ diamond in their rose gold mounting. After measuring I told them the cutlet would protrude through the bottom given the rings current thickness. They said the stone has to be low as no tall head would be accepted by the customer. I suggested fabricating a tapered under bezel gallery to raise the top of the ring off the finger. It was out of their price range.
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| I asked if they were sure a ½ mm bezel would be too tall. They looked through their Southeastern Findings catalog at the 5-6 straight bezels and said these were too high. I laughed and said it doesn’t matter as no one carries them in 18K rose gold anyway. The bezel has to be made from 20ga. 18k rose gold wire. They gave the go ahead. | |
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2. The raw 18K rose gold 20ga wire is too wide when compared to the diamond. Running it through the rolling mill to make flat sides and reduce its thickness by ½ makes it perfect. Re-anneal the rose gold after rolling it. Rose gold needs to be quenched before cooling below 900deg. This helps keep the metal homogenous and prevents the copper and gold atoms from forming separate layers like in air cooled rose gold. Failure to do this will create major cracks forming between the bands of copper and gold atoms. My thanks go to you Eddie Bell for the tip on that. |
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3. Once the wire is rolled flatter, clamp it in a holder as shown. Small vise grips will work also. Now you need to take a 1.1mm bearing burr and run it down the middle of the wire to create the channel for the girdle of the diamond. We are trying to make the look of a heavy rose gold cinch bezel. |
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4. With the bezel made and curved to fit the diamond diameter it’s pinched and, under pressure, soldered or laser welded together. If you did a good job the diamond is tight and doesn’t rattle. |
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5. The bezel is now welded top and bottom and ready to burnish the joint to bring the metal up to the density and strength of the drawn wire. |
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6. Now it is time for some fun. Set the laser at 2 mm beam diameter and the voltage at 200 and the MS at 2 and adjust the hertz as high as it goes. This should not even melt the surface but it will warm the ring enough to pull the onyx and not even burn the glue. |
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7. With the onyx removed, clean out any glue residue. Then burr the hole to fit the diamonds’ diameter like you were going to bead set it. As you can see the bezel went edge to edge and was a good fit. The gap at the sides, because of the band’s natural curve, makes it unnecessary to bevel the bottom of the bezel for a strong laser joint. You already have plenty of space to fill. |
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8. With rose gold’s high copper content you need to crank the power up to weld it. Copper is a fast heat conductor like silver and almost as reflective so adding 25% to an alloy makes a big difference over regular 14k and almost the same in 18K. On the sides you crank the voltage even higher to pound the metal back under the bezel. This is 28ga rose gold wire as filler. |
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9. The finished weld is now ready to rotary burnish in order to make it denser and remove any pits. |
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10. The knife edge burnisher is the burnisher of choice here. It makes a tight 90 degree angle at the weld and smears closed any pits. It’s time to clean up now. I used a knife-edge abrasive wheel here before polishing. |
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11. If your diamond is loose, a quick burnishing will tighten it as well as give a finished edge to the inside of the bezel. |
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12. I polished the top with a yellow or magenta (stiff wheel) knife edge wheel so I could direct the wheel more precisely to prevent any grooving between the bezel and the shank. Then I used a regular wheel to lightly remove any swirl marks. I was told the customer loved it. |
This article first appeared in Bench Magazine http://www.BenchMagazine.com
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