Professional Jeweler Archive: Using a Laser Welder for Ring Sizing

November 2001

Professional Bench/Defining Quality


Using a Laser Welder for Ring Sizing

Knowing how to use this technique demonstrates another aspect of quality in your shop


Most bench jewelers are so efficient sizing rings with traditional torch-soldering methods that the joints seldom fail. Why then should you bother with laser welding, which may require additional time? Laser welding yields a stronger joint and can be performed without removing heat-sensitive stones.

At Underwood’s Fine Jewelers in Fayetteville, AR, customers are given a choice of torch soldering or laser welding, which costs 50% more. Here are some reasons customers often choose laser welding:

  • It’s stronger than soldering and it’s all alloy, void of solder.
  • There’s no extra charge to have heat-sensitive gems removed so the final cost may actually be lower.
  • There’s no oxidation or other factors that diminish detail or require special handling near finishes or engraving.

Underwood’s sales associates were trained to sell the features of laser welding. They learned details in staff meetings, read packets of information and individually performed some laser welding. Once they fully understood the benefits, the barriers to selling the process came down and laser-welding sales went up. Underwood’s expects that through increased sales of work performed with the laser welder, the machine will pay for itself in two years.


Steps for Professional Ring Sizing With a Laser Welder


Preparation

A standard solder joint.

For torch soldering or laser welding a karat gold or platinum ring, a professionally prepared joint has no gaps or irregularities. Both portions of the ring’s shank are aligned evenly.

An incomplete weld.

When trying to laser weld a joint prepared for sizing using traditional torch methods, you may encounter a “cold” weld, as shown in this cross-section. The outer portion of the ring’s shank was successfully welded, but the inner portion has no contact and is sure to fail during normal wear.

When preparing the joint for sizing with a laser welder, open the top portion slightly and use a build-up process, resulting in complete contact in the weld area.

In a professionally prepared laser weld joint for ring sizing:

A. There is contact at the bottom portion of the ring shank.

B. There is no contact at the top portion of the ring shank, and the gap has an appearance of a slim, elongated Y.

Performing the Weld

1. Direct the laser beam through the opening at the top of the shank and weld the bottom portion with a series of pulses.

The red arrow shows the bottom of the shank intact. The blue arrows show the direction of the laser beam.

2. Lay a piece of 29-gauge round wire lengthways in the joint. Be sure to match the alloy of the ring you’re welding. The wire should be slightly longer than the shank’s width.

Round wire placed in joint.

3. Adjust your laser welder to the correct settings for this application. Typically, you increase power and narrow the beam. Use pulses to weld the joint, ensuring the pulse is directed at the metal in the ring’s shank and the wire.

4. Continue building up the weld until the void is filled.

5. Readjust the settings by decreasing the power and increasing the diameter of the beam. This softer, broader pulse is for final “smoothing.”

Related Notes
  • You may have to anneal some rings before laser welding for ease in reshaping the shank afterward. Otherwise, the area that was welded will become malleable, but the rest of the ring will remain work-hardened and may crack when rerounded. The area immediately adjacent to the welded joint is most vulnerable.
  • Underwood’s primarily uses traditional methods for sterling silver and nickel-based white gold.
– Mark B. Mann, Director of Trade Programs, Jewelers of America

Technical Contributions by Tom Weishaar, JA® Certified Master Bench Jeweler™ and Shop Manager, Underwood’s Fine Jewelers, Fayetteville, AR

Sizing rings is required for the first level of the JA® Bench Jeweler Certification™ Program.

© Copyright 2001 Jewelers of America Inc.
Illustrations by Lainie Mann – Visual Communications




The JA® Professional’s Guide to Fine Jewelry Craftsmanship

Using a Laser Welder for Ring Sizing

By Mark B. Mann, Director of Trade programs, Jewelers of America®

A. The depth of the shank follows the design configuration from top to bottom when viewed from the side. There are no signs of overfiling.

B. The width of the shank follows the design configuration when viewed in profile.

C. The style of the shank is maintained consistently around the base, and the integrity of the taper, half-round, flat or knife-edge shape is not lost.

D. There are no visible seams, cold or incomplete joints or pits at the seam.

E. The inside of the ring is even, smooth and highly polished.

F. The shank is close to its original thickness and width, with little or no dimensional loss.

Potential Problems to Watch for

The Shank Is Cracked

The ring wasn’t annealed before laser welding so it cracked when it was reshaped.


Welded Area Has Pits

Adjustments to the laser welding equipment were incorrect or the improper technique was used in welding, resulting in pits at the welded area.


Dimensional Loss in Shank Thickness and/or Width

The shank wasn’t aligned carefully when the weld was performed. There will be significant dimensional loss when the excess material is removed.


Incomplete or Cold Joint

The starting joint was closed and the beam didn’t reach the central portion of the shank, resulting in no contact.

This information is required for first level of the JA® Bench Jeweler Certification™ program.

© 2001 Jewelers of America Inc.
Illustrations by Lainie Mann – Visual Communications

Copyright © 2001 by Bond Communications