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This article
covers 950 palladium methods and techniques for: - The assembly
of mountings and findings
- Soldering
- Sizing up
- Finishing
The reintroduction of white, bright and light palladium for use in
the jewelry industry has quickly introduced an expanding assortment
of palladium stock items offered in a variety of palladium alloys.
These alloys contain 950 parts of palladium and 50 parts of other metals
(this portion of the alloy may vary among suppliers). The most common
alloy component is ruthenium, which, along with palladium belongs to
the platinum group of noble metals. Ruthenium usually comprises about
4.8 percent of the 5% mixture, leaving room for trace elements of other
metals that improve working, wearing or casting characteristics. This
alloy combination is suitable for general purposes such as casting
and fabricating and has an as-cast Vickers hardness of about 110 to
130 depending upon the specific mixture. Other 950 palladium alloys may include in their 5% mixture metals
such as nickel, copper, silver, cobalt, and various combinations of
these. These alloys will range in working characteristics for various
bench and manufacturing tasks.
It is very important to know about the 950 palladium alloy that you
are working with and to become familiar with their compatible features.
Because the ingredients of 950 palladium alloys vary, so may factors
such as color and working characteristics. For the best results when
sizing, servicing or building jewelry pieces at the bench, use like
materials.
This article features stock pieces (in this case, a cast mounting
and a die struck setting) that were provided by R-Findings,
Rochester, NY. They have a large selection of 950 palladium mountings,
findings, sizing wire and solder. The provided R-Finding's palladium
products are made from a 950 palladium and ruthenium alloy that is
mixed with trace elements of other metals.
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The 950 palladium mounting is cast and pre-finished.
There are some parting lines and other minor details that need removal.
For the inside of the mounting (deeply stamped 950 Pd from the supplier)
silicone abrasive cylinders from Stuller were used to smooth and prepare
for polishing. |
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The grits of these abrasive cylinders range progressively from coarse
to extra-fine. Because the mounting was delivered in a pre-finished
state from the supplier, only the two finest grit cylinder wheels were
necessary to complete the job.
Tip: Palladium requires fewer steps for pre-finishing and polishing
as compared to platinum. Polishing palladium is made more efficient
by pre-finishing with a series of fine abrasives, which may require
a few extra steps as compared to white gold alloys. |
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For the outside of the mounting, 3M's FX polishing wheels were used.
Again, the mounting was nicely pre-finished so only the extra-fine
1,500 and 3,000 grit wheels were used to brighten the mounting.
Tip: 3M's FX polishing wheels are ideal for use with palladium.
They range in grit from 240 to 3,000 and the unique core material
will conform to the shape of the object being pre-finished. Because
the wheels contain fine polishing grit, they do not require polishing
compounds. This makes them cleaner to use as well as more efficient. |
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To prepare for soldering, the setting is fit onto the mounting. Next
a hole is drilled to receive a peg type setting. The peg is square
measuring 0.90 X 0.90 mm and 1.30 mm across the diagonal. A 1.01mm
drill bit was used so the fit of the peg was snug and held itself in
place for soldering. Once the fit was adjusted, the setting and mounting
were polished prior to soldering using Bendick white rouge. Then the
assembly was soldered using R Findings' easy flowing palladium solder.
(Please see the first image of this article showing the solder used
and the assembly being soldered on the high-heat soldering block). |
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The mounting developed a very slight surface discoloration or light
oxidation. The discoloration ranges from blue to violet. Though it
cannot be removed by pickling, it is simple to correct using a variety
of methods.
Tip: Methods for removing surface discoloration include use of a
neutral flame, use of fine abrasives or just polishing. |
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With this assembly, the most efficient way to eliminate the surface
discoloration is to use a neutral flame (a mild flame with equal parts
of natural gas and oxygen). The ring was mildly heated for 20 seconds,
after which the mounting returned to its pre-soldering polished luster.
Tip: Use of higher heat palladium solders (medium and hard) will
also cause palladium to slightly discolor. A neutral flame may reduce
the discoloration to a dull white which can be quickly re-polished. |
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Soldering palladium requires no flux or fire coating solution (unless
gemstones are present). When soldering or annealing always wear protective
welding eyewear (A) with a minimum darkness rating of 5. A high-heat
or platinum soldering block is used (B) for most soldering applications.
Make an effort to keep solder clean and free of debris. Here, chips
of solder are prepared for use and kept off the bench on a small clean
plate (C). R Findings supplies easy and medium palladium solder in
sheet form (D). |
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The excess peg material is removed by hand filing and use of rotary
abrasives. Two very small pits were detected in the solder joint around
the peg so a rotating, highly polished tungsten carbide burnisher was
used as shown to blend them into the ring. |
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After the burnishing process, an extra-fine small rubberized diamond
abrasive wheel was used to remove the traces of the burnishing and
to pre-polish the mounting in the area of the assembly. |
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The ring was again polished with Bendick rouge and the center stone
set. Palladium has little or no memory so the prongs did not spring
back during the setting process. |
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With the sale of the ring, sizing is required. For sizing the ring
up, the shank is cut and a small piece of palladium sizing stock (provided
by R Findings and made from the same alloy as the ring) is inserted.
R Findings advises the use of their medium palladium solder for soldering
of sizing joints. Small snippets of that solder were placed on each
side of the sizing stock and the soldering was completed using a natural
gas and oxygen torch. The joints are mildly but quickly heated. The
shank and the sizing stock reach solder melt and flow temperatures
simultaneously. The gemstone was fire coated (but not the ring) with
a mixture of denatured alcohol and powdered boric acid. |
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This time after soldering, the ring has much less surface discoloration
but because of the higher heat solder, the area on each side of the
joint lost its polished luster. |
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To protect the gemstone from being damaged by heat, it is coated
again. Then, a neutral flame is again used to remove the discoloration.
Filing and polishing reveals a clean smooth joint |
Polishing Palladium Made Easy!
Brenda Warburton of Austin and Warburton in Ann Arbor , MI uses a very effective
ONE-STEP polishing process for palladium jewelry. After doing fine abrasive
pre-finishing, she uses white Bendick Rouge from C. R. Hill Company to produce
a fine finished luster. This amazing rouge eliminates fine scratches and reveals
the natural bright, white color of palladium.
Palladium Jewelry Manufacturing: Frequently Asked Questions:
Does 950 palladium jewelry require rhodium plating?
" NO!
Palladium is bright white. For the whitest, brightest results when polishing
palladium use white jeweler's rouge and then white 8,000 grit platinum rouge
as the final step in the polishing process. The acquired finish after these
two polishing compounds are used will rival rhodium plated white gold. Palladium
however will keep its natural whiteness over time, unlike most white gold alloys
which depend on rhodium plating to become white and to maintain whiteness over
the years. |
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