950 Palladium Fabrication + Assembly
This article covers methods and techniques for hand fabrication, soldering, and assembly for a custom-designed, 950 palladium and cultured pearl ring.
By Mark and Lainie Mann -- JCK-Jewelers Circular Keystone, 10/1/2006
This bold yet minimalist ring design features a 10 mm cultured pearl set in 950 palladium with a wide, rounded inner and outer shank for comfort and surface contrast. The ring was hand fabricated using Hoover & Strong's low-dome, half-round 950 TruPd palladium wire stock from their palladium product catalog. The finished weight of the ring is 9.2 pennyweights. In platinum, the identical design would have weighed nearly 16 pennyweights.
1
The 950 palladium, low-dome, half-round wire on the left of figure 1 measures 8 mm wide and is 1.7 mm deep and will be used for the inner shank with the rounded contour inside the finger hole. The wire on the right measures 10 × 1.5 mm and will be used for the outer shank with the rounded contour on the outside. The flat sides of the wires will face each other and become the joint surfaces.
2
The wire was difficult to bend as supplied by Hoover & Strong, so individually they were placed on a platinum soldering block and annealed. Because this wire is wide and heavy, a vented torch tip was used.
Tip: The low-dome, half-round wire was annealed using a natural gas and oxygen torch with a vented tip. The temperature of the wire was brought up to annealing temperature (indicated by a bright orange color) and held for 30 to 45 seconds. Once the wire reaches an annealing temperature, the torch was raised upward away from the wire to hold the temperature. Failure to raise the torch could cause the wire to be overheated. To protect your eyes during palladium annealing or soldering procedures, always use a welding lens rated No. 5 or higher. No firecoat solution or flux is used.
3
The wires were cooled to room temperature. The inner wire was formed by hand, bending it around a ring mandrel. After making it the proper ring size, an end-to-end joint was created with no open seam. The half-rounded shape formed the inside (finger hole) of the ring and the flat side faced outward. To connect the joint, 950 palladium hard solder was used. After soldering, the ring was rounded and then filed flat using a cross-filing technique.
Tip: Using hard palladium solder provides the best color match and results in a joint that's not visible when polished and finished.
4
With the inner shank piece made, the outer portion is formed. The annealed outer shank wire is marked with dividers at key bending and forming points.
5
Using a ring mandrel and ring-forming pliers, the shank is shaped. Thin paper was folded in half, and half of the shank outline was traced darkly and cleanly onto the paper. The paper was turned over and the other half carefully traced, using the guide from the first half. The unfolded paper served as a symmetrical guide for forming the outer shank. Because the wire was laid over the guide and matched often throughout the forming process, the result was a symmetrical piece that fit perfectly with the inner shank.
6
Next, the outer shank will be soldered to the inner shank. The inner shank is placed in the outer shank, and the three main contact points are marked with an indelible ink marker. A small ball bur and a high-speed Foredom Micromotor are used to create depressions inside the outer shank to melt easy palladium solder into.
Tip: The Foredom Micromotor has moderately good torque at medium to high speeds. A cut or groove can be controlled and positioned in metal. High speed keeps lubricated burs from grabbing or wandering.
7
After the outer shank portion of the ring was shaped, it was prefinished to a fine abrasive finish. The piece was placed on the soldering block and easy-flowing TruPd solder was melted into the divot.
8
After the ring cooled to room temperature, the inner and outer pieces were fit and final adjustments made. There was good contact and tension between the pieces, and they were soldered using the easy solder that was premelted into the depressions at three points of contact. A vented torch tip was used because of the volume and weight of the pieces. No firecoat solution or flux is used for soldering palladium to palladium. The heat from the torch was directed to the heavier outer portion of the shank and the platinum block immediately in front of the ring. The heat radiated inward and the solder that was melted into the depression was flown at the connection between the two shank pieces.
9
During this part of the soldering procedure, the ring lost its prefinished luster and picked up a slight blue-purple surface discoloration. The surface discoloration is removed by heating it on the platinum soldering block with a mild, neutral flame. Surface discoloration can also be removed mechanically with fine abrasives such as 3M's radial bristle discs.
10
To restore the ring to its prefinished luster, 3M's radial bristle discs were used. There are six color-coded grits in this system, and the middle grit (blue) and two finer wheels were used.
11
For an evenly flat surface on each side of the ring, a Foredom bench lathe was used with 3M's 3-inch discs of diamond-polishing cloth. Progressive grits were used from medium to ultrafine. Abrasive wheels were used to remove tool marks and refine the shape.
12
After the prefinishing, the ring was placed in a magnetic finisher. Water was filled to the indicator line on the side of the bowl and about 10 drops of Stuller's MF610 burnishing compound (the green liquid in the squirt bottle next to the finisher) were used. The piece was tumbled for 20 minutes.
13
The tumbling procedure brightens the entire ring including the areas difficult to access. The finish left by the magnetic finisher is bright with ultrafine percussion marks. It's now ready for polishing.
Polishing Notes: The ring was polished after the magnetic finishing in two steps. The first step included using Bendicks rouge (available from C. R. Hill in Berkley, Mich.) and a treated yellow stitched buff. This white rouge works as a one-step polishing compound for palladium. It has moderate cutting capabilities while delivering a bright finished luster. The second step of polishing this ring included using Foredom's platinum white compound, which produced a deep, true bright white luster on the palladium.
| Author Information |
| Mark and Lainie Mann are co-founders of Visual Communications Inc., a company that provides jewelry-manufacturing technical content; professional images; product testing, research, and development; and presentation and publication of shop, bench, and service department emerging technologies. They produce professional and technical articles appearing exclusively in print in JCK magazine, online at www.jckmagazine.com, and at www.ganoksin.com, the Orchid Web site. Mark Mann was formerly the director of certification and trade programs at Jewelers of America and prior to that, director of manufacturing arts at the Gemological Institute of America. For technical information regarding working with palladium, contact Mark B. Mann at mmann@luxurypalladium.com or call (406) 961-4426. |
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