Professional Jeweler Archive: Repairing Porosity Using Laser Technology

April 2003

Professional Bench/Defining Quality


Repairing Porosity Using Laser Technology

Knowing how to repair porosity on a karat gold men's ring demonstrates another aspect of quality in your shop


This month we demonstrate how to use laser welding to repair porosity on a customer’s ring brought in for sizing. The sales associate who took in the ring at Galloway & Moseley in Sumter, SC, quoted charges for the sizing and repair of the porosity. Here’s how Galloway & Moseley’s Steece Hermanson repaired the porosity.

Repairing Porosity

1. Hermanson cleans the ring thoroughly. He locates three areas of porosity: two inside the ring and the other – a minor cluster of pits – on the outside surface. Two areas of porosity are shown.
2. One cluster of porosity is inside the ring, close to the gemstone. Hermanson covers the bottom of the gem with Bergeon Rodico, a pliable turquoise-colored compound used by watchmakers, to protect it from a stray pulse of energy, which could break it.
3. Then he condenses and smooths the heaviest area of porosity. He sets his laser welder at 260 volts, 3.3 milliseconds with a focus of 8. With this setting he’s able to blend and smooth the heaviest areas of porosity using a series of pulses.
4. Now he’s ready to build up the depressed area the first step created. He places the tip of 14k yellow gold 29-gauge round wire at the deepest part of the depression and hits it with a pulse of energy from the laser welder. The wire is welded into the depression. With a flick of his wrist, he breaks off the wire and repeats the procedure several times. If the depressed area is open, he will keep the wire in place without breaking it off and continue to direct pulses of energy at the tip of the wire. For this step, his laser welder unit is set to 300 volts, 3.7 milliseconds with a focus of 17.
5. Now he’s ready to remove the watchmaker’s compound. Using an ultrasonic, he removes the surface discoloration before final preparation.

6. With files, abrasive wheels and sanding sticks, he prepares the surface for polishing using a cross-sanding technique. He notes a few pits and indentations in the otherwise flat, even surface of the ring after prefinishing. He builds up these areas using the same laser process, then completes surface preparation and polishes.

Procedure Summary

Repairing the porosity on the ring required eight minutes from start to finish.

For questions related to this process, contact Steece Hermanson at shermanson@ftc-i.net or Mark B. Mann at markbmann@aol.com.

– by Mark B. Mann

Technical contributions by JA® Certified Master Bench Jeweler Steece Hermanson
Galloway & Moseley, Sumter, SC

Illustrations by Lainie Mann
©2003 Visual Communications


Repairing Porosity Using Laser Technology

A. All areas of porosity have been repaired. Very minor specks may be visible using 10X or greater magnification.

B. The surface is smooth, even and highly polished.

C. There are no divots, indentations or other surface imperfections.

D. The gemstone was properly protected; stray pulses of energy did not chip or break it.

– by Mark B. Mann

Illustrations by Lainie Mann
©2003 Visual Communications

This series is sponsored in part by Jewelers of America, (800) 223-0673

Copyright © 2003 by Bond Communications