Professional Jeweler Archive: Sizing Channel-Set Rings

August 2000

For Your Staff/Defining Quality


Sizing Channel-Set Rings

Knowing how to perform this task demonstrates another apsect of quality in your shop


Rings with channel-set stones require special handling any time you perform routine service or sizing. In this installment, we focus on resizing channel-set rings and give you tips and techniques to get professional results.

To illustrate, we’ll use a common channel-set design: the anniversary ring channel-set in perpendicular walls.
Anniversary Ring

Steps to Follow

The first step in this process – as in any repair – is to clean and inspect the entire ring. Check all stones for looseness and damage and then inspect the ring itself for problems such as cracks, porosity or thin areas. These conditions can affect the finished job, so be sure to inform the customer if you find any of them during your inspection.

–by Mark B. Mann, Director of Professional Certification, Jewelers of America

Instructions: Change the ring from size 81/4 to size 6.

1. Ensure the ring is round by placing it on a mandrel. If it’s not round, adjust as necessary (see box below).

Rounding a Ring

The ring at right is out of round at the top (likely because of errors in the original manufacturing process). To reround, place the ring over the eight-leaf mandrel of a ring stretcher (below). Inexpensive stretchers have fewer leaves; the more leaves, the better the process will go.

Next, use very, very small incremental pulls on the stretching lever, rotating the ring while pulling on the stretching lever. The fans of the mandrel will expand and pull the ring back into a rounded shape.

Important! Don’t try to stretch a ring with stones or make too much of an adjustment in any one step – the ring will simply break or “tear” at its weakest point.

2. Saw the ring at the bottom of the shank.

3. Size down the ring in increments. First remove enough metal to come down about a half size.

4. Resolder the ring at the joint.

5. Place it on your ring mandrel and reround it.

6. Check again for loose stones. By decreasing the size, you are pulling the walls away from the stones, causing them to loosen.

7. Tighten any loose stones. One way is to place the ring over a mandrel, then set the mandrel into the cutout in your jeweler’s workbench (illustration below). Using a hammer and punch, lightly hammer the metal downward. The punch should be about the same width – or slightly wider – than the channel wall (illustrations at bottom and right).
Place the ring on a mandrel that rests in the cutout of your jeweler’s bench.
Use a hammer and punch to push the metal down over the stones. Use a punch the same width as the channel wall.

8. Cut the ring again at the same location as before and remove about a quarter size to a half size.

9. Resolder.

10. Check for loose stones and retighten as described above.

11. Repeat this process until the ring is size 6 (or the desired final size).

12. File and repolish. Always check for loose stones as a final step.

More Time, More Expertise

Sizing in incremental steps allows you to make major adjustments to the size of channel-set rings whether the channel walls are perpendicular (as in this example) or parallel. Parallel walls are less likely to need such small incremental adjustments.

This process takes longer and requires more expertise than sizing other types of rings. You should certainly charge more for this service than for a standard sizing job.

The JA Professional's Guide to Fine Jewelry Craftmanship
Sizing Channel-Set Rings

Professionally Sized Channel-Set Ring

A. There are no visible solder joints, pits or sizing seams.

B. The transition between each side of the shank is smooth, symmetrical and even, with no dimensional reduction in any area.

C. The detail is sharp, crisp and even in appearance, not overfiled or overpolished.

D. The inside of the shank is smooth, has no sharp edges and has been finished to a new and lustrous condition.

E. The new shank isn’t too thick or too thin and is the correct finger size.

F. There are no loose, abraded or otherwise damaged stones. They’re all level.

G. There are no tool marks across the top where hammering took place to tighten the stones.

Potential Problems to Watch For

This shank has been poorly handled. The sides don’t meet evenly, the solder seams are visible and too much metal was removed through a careless attempt to size down the ring. Tool marks were left when tightening the stone.
There was no attempt to tighten the stones, so many are loose. Check tightness by placing a fine-point pair of tweezers on the girdle of the stone and “twisting” from side to side. The stone should not move.
These stones (not diamonds) were damaged by using an abrasive wheel in a careless manner.

© 2000 Jewelers of America Inc.
This information is required for the second level of the JA® Certified Bench Jeweler™ program.

The installments published in Professional Jeweler from February 1998 to July 1999 have been reformatted and published by Jewelers of America as a countertop book titled The JA Professional’s Guide to Fine Jewelry Craftsmanship. To buy a copy, contact one of the following suppliers: Gesswein, GIA Bookstore, Rio Grande and Stuller Settings. Or call JA at (800) 223-0673.

Illustrations by Lainie Mann – Visual Communications

Copyright © 2001 by Bond Communications