January 2003

Professional Bench/Welding Technologies

Common Fusion Welding Applications

Knowing how to tack-, fusion- and pulse-arc-weld at the bench saves time, boosts quality and drives profits up for your store's repair shop

Fusion Welding: A method of permanently welding precious metal findings and parts to jewelry components. Fusion welding requires no soldering, follow-up with a torch or other welding applications. Use of fusion welding significantly reduces working, prefinishing and polishing time.

Most findings for fusion welding are commercially made and have a small nib protruding from a pad or broad base.

To perform a permanent fusion weld, place the finding precisely perpendicular over the location where its to be attached. Contact occurs between the piece of jewelry and the tip of the nib on the finding. Light to medium pressure is required for successful fusion welding.

When the ABI Tack II welder discharges electrical current, a high level of resistance is created between the small nib and the work piece. This action causes the bottom of the pad and the metal directly below the pad on the work piece to melt and flow together solidifying instantaneously. The instantaneous achievement of the permanent fusion weld prevents heat from transferring to the surrounding metal. This procedure eliminates oxidation (typical from a torch procedure) and the potential to damage heat sensitive materials and gemstones. When fusion welding, no parts are annealed. It also minimizes the amount of time spent over standard torch procedures.

Fusion Welding Applications

Fusion welding applications at the bench are endless using ABIs Tack II welder. To master the process, practice is required on like materials of equal volume prior to working on one-of-a-kind repair. Following are some everyday tasks for a bench jeweler generalist that can be accomplished more proficiently by using fusion-welding procedures:

A nib is a small protrusion (see arrows) from a larger base or pad located at the attachment location on a finding. In some cases, an operator can make a fusion finding by raising a small fissure of metal from the base platform.

Repair of 14k Yellow Gold Tourmaline and Diamond Earrings with an Earring Post Broken Off. Earrings Have Omega Clips.

1. 14k yellow gold earrings with a broken post. For the best quality repair, both posts will be replaced by permanent fusion welding using fusion findings. The arrows indicate the broken post and location for a new one.
2. The back of the earrings at the weld joint must be perfectly flat. Heavy tweezers hold the earring and are connected to the negative lead. Pliers secure the post and are connected to the positive lead. Arrow indicates the base of the fusion post. Only the nib is in contact with the earring.
3. The foot pedal of the ABI welder is depressed and the fusion weld is instantaneously completed. The unit was set on the low energy setting at 40 volts. A minor amount of surface discoloration was removed by ultrasonic cleaning.
4. Using this procedure and equipment did not require unmounting and resetting stones, removal and replacement of the omega clips or significant repolishing.

Repair of a Sterling Silver Tie-Tack with Post Broken Off. The Tie-Tack Is Inlaid with Coral, Mother of Pearl and Turquoise.

1. Inlaid sterling silver tie-tack with a broken sterling tie-tac post.
2. The piece is cleaned and the oxidation removed. The area on the back where the sterling silver post will be attached is prepared. A karat-gold post will be used for additional rigidity. The post is inserted into the collet of the offset fusion weld pencil.
3. The tie-tack is placed face down on the weld contact pad. A piece of Scotch® Magictape is on the contact pad between the tie-tack and pad as an insulator. The offset fusion weld pencil is positioned and the post welded onto the tie-tack.
4. The finished piece required minimal polishing. ABI welder was set on the low energy setting and 50 volts was used.

Manufacturing Run of Cast Earrings with Fusion Welded Posts.

1. 14k yellow gold cast S-shape earrings. These earrings are regular sellers so the store makes 24 pairs at a time.
2. The S castings are finished and prepared for assembly. The posts are fusion welded using tweezers to the negative pole and pliers to the positive.
3. The ABI welder is set on the low-energy setting at 40 volts. The foot pedal is depressed and the earrings are instantly and permanently fusion-welded. After welding, they are magnetic finished to brighten. A quick final polish is applied.
4. For the manufacturing run, time was saved in the assembly and welding and no parts were annealed in the process.

To Learn More

For a detailed overview of fusion welding for granulation, see the series entitled A New Technology to Manufacture Jewelry with Granulation, Bead by Bead in Professional Jeweler August 2002 - November 2002.

This tack-, fusion- and pulse-arc welding technologies educational series is sponsored by ABI of Cranston, RI. For general information related to ABI equipment and procedures or for a list of distributors, call Janet Kirk at (888) 494-2663.

by Mark B. Mann

Technical Contributions by Steece Hermanson, Galloway and Moseley, Sumter, SC

Illustrations by Lainie Mann
Photographs by Mark Mann

© 2002 Visual Communications

Copyright © 2003 by Bond Communications