Precious Metals: Metalsmithing
Hard new alloy Plat/SK promises more lustrous, shiny
jewelry that's easier to polish and has a longer lasting finish and - very
likely - a lower cost. Plat/SK is expected to go on sale this month
A new harder platinum alloy, trademarked Plat/SK, has been invented by
Steven Kretchmer of Steven Kretchmer Designs, Palenville, NY. The alloy
should be available this month, distributed through Hoover & Strong,
Richmond, VA. It will be available in the distributor's next catalog.
You can sell Plat/SK jewelry as the latest and most exclusive platinum
available. This 95.5% pure platinum product is extremely hard in the as-cast
condition and can be made harder by subsequent heat treatments. Plat/SK
promises several key benefits, say designers who have created jewelry with
Left: These rings by Michael
Sugarman of Michael Sugarman Designs, Santa Fe, NM, were created with the
Right: Michael Good Designs
Inc. of Rockport, ME, used Plat/SK to create this mini-icicle pendant.
The metal is beautiful, says Kretchmer. Consumers will be attracted to
the mirror finish designers and manufacturers can create with the alloy,
he says. Manufacturers will notice Plat/SK is crisper and dryer than other
Plat/SK is easier to polish and, once polished, retains its finish longer.
The ease of polishing will save manufacturers about 20% in labor costs,
says Jean-Francois Albert of JFA Designs, Irvine, CA. Albert tested Plat/SK
and has incorporated it into his bridal line. As manufacturers begin to
work with Plat/SK, Kretchmer hopes they'll pass the labor-cost savings on
Jewelry makers can design lighter, thinner pieces using less of the alloy.
Because the alloy is harder than other platinum alloys, lighter jewelry
made from it will suffer no loss of durability, nor will it dent or bend.
It's springy and slides smoothly upon itself for clasps and other mechanical
parts. Other platinum alloys grab and drag.
Plat/SK is a derivative of the alloy Kretchmer developed for his well-known
tension settings. Kretchmer was granted two patents by the U.S. Patent Office
for the alloys and heat treatment process he uses in his tension settings,
properly called "metal compression-spring gemstone mountings."
The designer has a patent pending for the Plat/SK alloy as well.
Hoover & Strong hopes to have the alloy available this month in two
grades. One grade is more useful for casting, while the other lends itself
to forming or milling. (Milled products are great for fabricating, stamping
and anticlastic forming.)
Along with Albert, Michael Sugarman, Michael Good and Richard Messina
have tested Plat/SK; designers Eddie Sakamoto, Diana Vincent, Whitney Boin
and Michael Bondanza were experimenting with it at press time.
Consumers will learn about Plat/SK from Platinum Guild International.
PGI plans to promote Plat/SK as one of the highest purity platinum alloys
available. "PGI only promotes high-quality platinum," says Lisa
Labrado of PGI. Promotions are still being worked out, she says. Seminars
on how to sell this new platinum alloy are will be available from PGI.
Bench jewelers will see differences when working with Plat/SK instead
of other alloys, say those who've already experimented with it:
- Plat/SK is harder than iridium, ruthenium and cobalt platinum alloys.
Standard platinum alloys drag, stick and damage tools. Plat/SK machines
better with less tool wear, say Hoover & Strong machinists and manufacturers
who've worked with the alloy.
- Plat/SK polishes like 18k gold, though the polish won't deteriorate
like it can on gold. "This cuts anywhere from a third to half off
the finishing time," says Sugarman.
- Soldering lines can be less visible from polishing.
- You'll be able to make thin, hollow pieces that won't dent or bend.
With regular platinum, these types of pieces are fragile.
- Plat/SK is good for clasps, pin stems and other objects that need to
be springy. Parts for catches and clasps from previous alloys drag and
- Plat/SK doesn't spring back when passing from elastic range to plastic
A Few Cautions
As with any new development, there are a couple of disadvantages, says
- During heat treatment or soldering fabrication, Plat/SK develops a
slight patina. This patina can be removed with an acid dip or slight polishing.
Kretchmer is working to refine the alloy and eliminate this problem.
- There's potential for fracturing. As a metal becomes harder, it grows
less malleable - and the potential for fracture under "stressful deformation"
(also known as bending) increases. Manufacturers can resolve this problem
by annealing the metal more often.
- by Lorraine M. Suermann
Copyright © 1998 by Bond Communications.