Professional Jeweler Archive: Torch Techniques

May 2002

Professional Bench/Path to Proficiency


Torch Techniques

Sizing rings with heat-sensitive gems


In this article, Steece Hermanson demonstrates how to size down a 14k yellow gold ring using water as a protection for the heat-sensitive gemstones. He’ll use a torch and hard solder to complete the job.

Hermanson needs to size down this ring, which contains channel-set peridot, aquamarine, amethyst and citrine, all of which would be damaged easily if they came into contact with the heat required for hard solder if unprotected.

First, he removes the necessary amount of material at the base of the shank by sawing to make the ring the desired size and prepares a butt solder joint. Using pliers, he realigns the shank. Then, as pictured below:

A. Hermanson uses an ABI Tack II tack welder and vacuum attachment lead to pick up a chip of 14k hard solder and tack-welds it over the solder joint.

B. He pours water in the tin to a level just above the last gem. Too much water would be a severe heat sink, hampering the hard-soldering process. Not enough water would cause the exposed gems to become damaged.

C. Hermanson places a small amount of modeling clay in the bottom of a tin. The clay holds the ring upright.

In photo above, Hermanson fire-coats the ring, preheats it and places a small amount of flux over and around the tack-welded piece of solder and the solder joint.

Next, he directs his torch flame at the lower portion of the ring to heat it and draw the solder through the shank

Hermanson leaves the torch on the shank for a moment after he watches the solder melt and flow. He wants to make sure the ring shank was hot enough to flow the solder completely through the joint. If the shank isn’t hot enough, the solder flows over and around the joint but doesn’t create a bond in the center of the joint. This is commonly referred to as a cold solder joint and will break open when worn by your customer.

To complete the job, Hermanson pickles, rinses and continues as if he soldered it without using water for protection during the soldering process.

Sizing rings with heat-sensitive gemstones is a requirement in the first level of JA’s Bench Jeweler Certification program. For information about bench jeweler certification, call JA at (800) 223-0673 or visit www.jewelers.org.

By Mark B. Mann, Director of Trade Programs Jewelers of America

Featured procedures by JA® Certified Master Bench Jeweler™ Steece Hermanson, Galloway and Moseley, Sumter, SC

Photographs courtesy of Jewelers of America

©2002 Jewelers of America

Copyright © 2002 by Bond Communications