This illustration is of a 14-karat white gold ring for three cultured freshwater pearls and two small accent diamonds.
Making a Pearl and Diamond Ring using Tack Welding
After preparing the wax, casting and pre-finishing, the ring was prepared for tack welding. There are 5 parts to be tacked, 2 small white gold settings and 3 white gold pearl posts. At each location for tacking the wire posts, a ball bur was used to create a small indentation slightly larger than the diameter of the wire (indicated by arrow).
Next a bud burr slightly larger than the overall diameter of the white gold setting was used to create a notch in the ring (indicated by arrow). Flashes of excess metal were removed from the notches.
With the ring prepared for tacking, the ABI Tack II was set on the high energy setting at 35 volts. A small notch was placed in the brass tack welding tweezers lead to securely hold the wire being tacked for the post. The bottom portion of the post was slightly rounded. One lead from the Tack II is attached to a third hand holding device. The other lead is attached to the tweezers. With the parts being held firmly together, a single pulse of energy was used to tack the parts.
After tacking the posts, the 2 settings were tacked. The energy settings were the same on the ABI Tack II. The tweezers used to hold the settings have been modified so there is even contact between two of the four prongs (indicated by arrows). This modification allows the user to firmly hold the settings for tacking. Loosely held parts can lead to destructive attempts.
The ring is held in a ring clamp with a copper plate insert (indicated by arrow). The wire from the lead is soldered to the copper plate and attached to one of the terminals. The tweezers are attached to the other terminal and a single pulse of energy is used to tack each setting.
With the parts properly positioned and tacked, the ring was firecoated and pre heated. A small chip of 14 karat easy white gold solder was placed with flux at each solder joint and the ring and parts were soldered. No extra holding devices were required and no shifting occurred during the soldering procedure.
With all parts soldered, the ring was again pre finished. The diamonds were set and the ring was polished and finished. The cultured freshwater pearls were glued and the ring again finally polished.
Tack-, fusion- and pulse-arc equipment settings will differ and are based upon the volume, amount of contact and alloy of the material you are working with. Practicing using like materials will give you a parameter for the settings required for your application. Keep a record of settings and tasks for future reference.
This content is published in a handbook along with other welding applications. To get a copy of the ABI Handbook of Welding Applications for Jewelry Design and Repair, contact Janet Kirk at 401-461-4140