950 Palladium
Creating a Traditional Palladium and Diamond Ring
By Mark and Lainie Mann, Mann Design Group, Inc.
This ring was designed by Lainie Mann using CAD 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.
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 diamonds—four on each side—using 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.
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.
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.
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.
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.
After seating the center stone, the ring was placed onto a 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.
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 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.
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.
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.
The preliminary final polish was done
using platinum blue compound. The
final luster was produced using 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.
Design and Rendering – Lainie Mann, Mann Design Group, Inc. Photographs – Mark B. Mann, Mann Design Group, Inc.
