This article describes the method of creating a traditional 950 Palladium and Diamond Ring.
Casting for this palladium ring project was done by TechForm, Portland , OR . TechForm specializes in casting stainless steel, platinum and palladium for the jewelry industry.
The 950 palladium and palladium solder used in this project is TruPd from Hoover & Strong, Richmond , VA. TruPd is available in sheet, wire, casting grain and a range of findings.
This ring was designed by Lainie Mann using Matrix jewelry design software. The customer requested the ring include all of the customer’s stones from another ring with the focus on the center stone inherited from her grandmother. The customer wanted the stones set closely together with a minimum of metal visible. The 5.80 mm center gemstone is surrounded by round brilliant diamonds ranging from 1.75mm to 2.7mm.
This ring design provides an excellent example for gemstone setting and working characteristics of 950 palladium. The superior white color of the alloy, its malleability and overall strength provide a sound and secure setting for the treasured gemstone and the diamonds that will last for generations.
Manufacturing methods and techniques covered in this project include:
- Design considerations for 950 palladium
- Rapid prototype model making for casting with 950 palladium
- Techniques for setting gemstones in shared prongs in 950 palladium
|This model of the ring design was produced by using rapid prototype technology and equipment. The computer generated design was e-mailed to Steven Adler at Automated 3D Modeling, Inc. in Rye, NH. Adler produced the model using a RapidToolmaker machine. While the material for this model is not wax, it burns out of investment molds creating a superior mold for 950 palladium casting. The surface is smooth and the detail is clean and well-defined.|
|The 950 Palladium ring was cast by TechForm in Portland, OR. TechForm is an industry leader for casting platinum and stainless steel and has recently included palladium casting in its services. The model was sprued in a few locations along one side of the shank.|
|In preparation for gemstone setting, the ring was pre-finished then polished with gray platinum Tripoli . The first gemstones to be set are the rows of diamonds on each side of the center grouping. The small prongs were shortened slightly by filing, then rounding using a cup bur of slightly larger diameter (arrow). |
Note: The pre-finishing process included tumbling the ring for 30 minutes in a magnetic finisher with stainless steel micro pins. This process provided a semi-polish to the 950 palladium ring giving a suitable luster to the hard-to-reach areas of the mounting.
|A setting bur was selected to create the bearings for the diamonds in the shared prongs (arrow). There are 6 diamonds on each side measuring exactly 1.90mm. The tungsten vanadium setting bur measured 1.80 mm. While burring the depth of the bearing, pressure was applied from side to side to slightly enlarge the bearing. |
Tip: When creating the bearings or seats in 950 palladium jewelry items, use lubrication such as oil of wintergreen, standard machine oil or bur lubricants with the setting bur. This helps to maintain its sharp cut, creating a precise bearing and reducing the friction that causes overheating. A flexible shaft with constant and reliable low speed torque and control, like the Foredom model SR or TX, is best for this process.
|A brass pusher was used to pick up and place the diamonds in their bearings. The brass pusher is made from 1/8th-in. brass rod and a wooden handle. The end of the brass rod is tapered. The end should be slightly smaller than the outside diameter of the diamond. A thin smear of beeswax is used to make the end of the brass rod tacky so it can pick up the diamond from the pre-assigned layout and position it in the bearing. |
Tip: These diamonds matched in diameter and proportions. If the diamonds are not matched, care must be taken when creating the bearings so their tables will be level and aligned when setting is complete.
|After placing the diamonds in their bearings and making sure they face up consistently with the curve of the setting, a beading tool is used to secure the diamonds in their bearings. Select a beading tool with a cup size slightly larger than the prong diameter. The beading tool is used again to shape the prongs. The same procedure is used to set the 1.75mm diamondsâfour on each sideâusing a 1.65mm setting bur and smaller beading tool. |
Tip: Lightly secure the stones in place, pushing the prongs only part way, and working opposing points of contact. This will allow you to make final alignment adjustments as the diamonds are secured in their settings.
|With the 1.90 and 1.75mm diamonds set, the next step is setting the diamonds immediately adjacent to the center stone. There are four 2.70mm diamonds and two 2.50mm diamonds to be set. Setting burs that are slightly smaller than the stone diameter are used to create the bearings. About 20% of the prong diameter is removed during the burring process from each side of the prongs.|
|All 6 diamonds are pushed into their bearings using a brass pusher. The prongs have been pre-shaped and as with the smaller diamonds, a beading tool will be used both to seat the stones in the bearings and to shape the tops.|
|Check for the consistent orientation and alignment of the tables and ensure that they face up evenly before finally securing the stones in their settings.|
|All stones are set and are ready for final shaping. For this step, a beading tool (cup size slightly larger than the prong diameter) has been shortened and fit into the Foredom Micro Motor Setting Handpiece. The unit is set at low impact adjusted so the foot pedal will control the speed of the handpiece. The beading tool is placed over individual prongs, being careful to avoid the diamond surface, to quickly and consistently shape the tops and to do the final compression of the metal over the diamonds.|
|To create the bearing for the 5.80mm center stone, a 3mm 90° bearing bur is selected. The bearing was established in the Matrix jewelry design software (arrow) and the goal in this sequence is to precisely shape that bearing. The fit of the center stone was checked throughout the burring process.|
|After seating the center stone, the ring was placed onto a GRS ring holding device for setting. The central portion of the holder expands to firmly hold the ring in place for hammering. The stone is first partially set on one side of the bezel, then the other. The setting punch is placed over the midpoint of the bezel and is lightly hammered with a chasing hammer, partially bending the metal over the stone. This procedure is continued from the midpoint outward on each half of the bezel.|
|With the center stone secured, the ring is then placed on a steel ring mandrel. The mandrel is placed into the bench slot created for it. A smaller setting punch and chasing hammer are used to perform the final bending of the bezel.|
|The preliminary final polish was done using Foredom’s platinum blue compound. The final luster was produced using Foredom’s 8,000 grit platinum white rouge compound. The finish of the 950 palladium ring has a nice bright white luster and does not require rhodium plating.|