March 2005 Bench | Welding Technologies Manufacturing a Sterling Silver with Platinum Bracelet Knowing how to pulse-arc-weld this project saves time, increases quality and drives profits up for your shop and service department By Mark B. Mann This article highlights pulse-arc-welding techniques used to make this sterling silver bracelet. 1. To demonstrate how pulse-arc welding performs on sterling silver, I cast, finished and assembled this bracelet without using a torch. The six links immediately adjacent to the clasp are made with a common sterling silver alloy; the other five are made using a new sterling alloy containing platinum developed by Marc Robinson of ABI Precious Metals, Carson, CA (for more information about the alloy, see page 76.) 2. The link on the left is made from a common sterling alloy and the one on the right is made from sterling containing platinum. Three mixtures of the sterling with platinum are available – I used one containing 3.5% platinum. I cast and prefinished the links and then used a magnetic pin finisher for a bright matte finish. 3. To prepare for the joining and welding, I sanded each end of the joining link flat. For an “aid” to the welding procedure, I did not remove the flashes of metal (red arrow) from each side of the link created by the sanding procedure. 4. For efficient welding, I joined five sets of two links and used the ABI Pulse Arc Welder to join them permanently. Because the links are sterling silver, the two-link combinations required less energy from the welder to complete than had I assembled the entire bracelet. For the double-link combinations, the pulse-arc-welder was set at 40 volts on the high energy setting. I used the No. 3 tip (it comes with five sizes of welding tips from No. 0 to No. 4). For welding, I viewed the work through the ABI Opti-Saver – magnification and auto-darkening lenses indicated by the red arrows. 5. I started the welding with a pulse of energy at the top of the link. When welding, I placed the ceramic collar on the joint and recessed the electrode about 1.5mm. The electrode was about 1mm from the joint. For the second and third steps, I used a pulse of energy at each side of the link. Last, I angled the tip and directed a pulse of energy toward the bottom of the link. This caused little deformation and only minor surface discoloration that was removed by pickling and ultrasonic cleaning. 6. This image shows the completed joint. The flashes of metal described in step 3 provided a little extra metal to melt onto the surface, minimizing the potential deformation of each link. 7. After I completed the double-link combinations, I joined all the links and welded the unfinished ones. Sterling silver is highly conductive so, with all the links joined, I increased the power to 50 volts and continued to use the #3 tip and the high energy setting. 8. There was very little difference when welding the common sterling silver alloy and the sterling containing platinum. This image shows a close-up of sterling with platinum links. 9. I joined the clasp to the bracelet with a sterling silver jump ring. To weld it, I set the ABI Pulse-Arc-Welder to 35 volts and the high energy setting and used the No. 3 tip. Because a torch wasn’t used, there was no oxidation or firescale. This process was as or more efficient than using a laser welder because no procedure was required to reduce reflectivity or filler material. Important: Tack-, fusion- and pulse-arc equipment settings will differ and are based on the volume, amount of contact and alloy of the material you work 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. For questions on this process, contact Mark B. Mann at mark@visualcominc.com or (406) 961-4426. To view related welding procedures, visit www.visualcominc.com. This installment is sponsored by ABI, Cranston, RI. For information on ABI equipment and procedures or for a list of distributors, call Janet Kirk at (888) 494-2663. Photographs by Mark B. Mann Visual Communications, Inc. © 2005