Professional Jeweler Archive: From Start to Finish, Part 2

May 2002

Professional Bench/Manufacturing Up Close

From Start to Finish, Part 2

Producing a platinum ring, starting with carving the wax through the finished piece

Wayne Lenkeit, owner of Lenkeit Manufacturing and a part-time instructor at the Revere Academy in San Francisco, CA, demonstrates making a custom ring from start to finish in this series. The center stone is an 8.08-ct. aquamarine and the side stones are Montana sapphires. The piece is cast using 5% ruthenium platinum.

This process is being shown from start to finish in consecutive issues. This is Part 2 in the series; see Professional Jeweler, April 2002, pp. 96-100 for Part 1.

Lenkeit has cast the ring, has removed the sprues and is ready to prefinish it. Here he uses a small belt sander with 120-grit emery abrasive paper in his lower lap-drawer.
Lenkeit modified his GRS Powerhone by adding an aluminum pan to collect abrasive waste. For this step, he uses a 3M Imperial Microfinishing abrasive disc and is wet lapping the top flat portion of the ring.
Lenkeit uses a medium grit rubberized rounded abrasive wheel to smooth the concave sides of his ring casting. Next, he will use a fine wheel, then an extra-fine wheel to smooth the same area.
Lenkeit uses multiple progressive grits to prefinish platinum castings. In this step, he uses a medium-grade 3M unitized abrasive wheel at the polishing lathe. These wheels, available in four abrasive grades, are designed with an open web non-loading abrasive surface.
He drills two alignment/screw holes on one side of the ring. The top portion of one side will be removed to accommodate his unique stone-setting procedure for the center stone.
Lenkeit has successfully finished the ring casting to a medium finish. He will take it to a finer finish once the formation of fabricated components is completed.
Using a separating disc as a dressing stone, Lenkeit modifies the top of a Krause bur to make a countersinking tool.
Here Lenkeit uses the Krause bur to enlarge each drilled hole at the top. This area will accommodate the heads of screws he’ll install later to reassemble the ring.
Lenkeit blackened the top of the ring with a marker and is scribing the location where the gem bearing will be located.
Lenkeit adjusts the height of the bur to cut the bearing to his scribed line. He uses the Foredom AllSet. He will place the ring top down and use a bearing bur to precut the bearing seat for the center stone.
Lenkeit precuts the bearing in both sides of the ring for the center stone. He lubricates the bearing bur with Bur Life, an important step for working platinum.
Precutting the bearing is complete. Additional cutting and final fitting will be required later.
Lenkeit will remove the top of one side of the ring. It will be reinstalled later, so very precise removal is critical. He selects the AllSet and a diamond cut-off wheel for the job and generously uses Bur Life while performing the cutting.
The diamond cut-off wheel is less than 0.20mm thick. The dimensional loss is minimal, which is important because the top will be reinstalled.
Lenkeit checks the fit of the center stone. He’s covered it with nail polish to protect it from damage while fitting and handling.
The next step is fitting and installing an under-gallery wire below the center stone. Here Lenkeit shapes the flat stock.
Lenkeit fits the under-gallery wire in position and uses utility wax to hold the center stone in position during the fitting process.
He carefully forms, fits and prepares the additional side wires the design calls for.
For platinum, very precise solder and assembly joints are required. Lenkeit ensures every piece is carefully fitted and aligned.
Lenkeit tapers the end of two of the wires using the flat side of the rolling mill.
He finishes the required tapers with the planishing hammer. In preparation for annealing, he pickles the pieces to remove any contaminants from the surface.
He now must anneal the materials he has cold-worked. Using rated welding lenses for eye protection and a sharp flame from a natural gas and oxygen torch, he anneals the material by bringing it up to a visible orange-hot color and holding it at that color for 60 seconds. He uses a silica-soldering block for temperatures this high.
After annealing, he completes the tapering and forming.
The ring’s major components are now ready for finer abrasive processing and prepolishing prior to assembly.

See the final steps in the manufacturing process of this platinum custom ring in next month’s issue of Professional Jeweler. Lenkeit Manufacturing (909-303-3660) performs custom design and manufacturing exclusively for retailers.

By Mark B. Mann, Director of Trade Programs, Jewelers of America

Technical contributions and the overall process demonstrated by Wayne Lenkeit, JA® Certified Master Bench Jeweler,™ Lenkeit Manufacturing, Temecula, CA

Finishing platinum is required for the third level of the JA® Bench Jewelers Certification program.

©2002 Jewelers of America
Photograph of the finished piece by Victoria Ward
Photographs of the work in progress by Colin Lenkeit

Copyright © 2002 by Bond Communications