This is the basic recipe for the
iridescent patina. This patina is most effective on highly textured
pieces, such as torch texture, rollerprinted and reticulation. It has a
slight color interference pattern, similar to oil on water. It has a
high natural luster, similar to the nacre on pearls, if done correctly
with many repeated dips in a weak solution. It is durable, the colors
remain stable to a high degree, and very slow (years) to darken or
further oxidize. Further oxidation can be prevented entirely by applying
Renaissance Wax when the patina is dry. It is effective on silver, brass
and copper, to a lesser degree with gold. This makes it an excellent
patina for keum-boo applications, since the 24 kt. gold content remains
bright.
Your metal should be thoroughly clean.
Wash, or use an ultrasonic, to cleanse off surface dirt and oil, then
rinse with clean water. Brass brushing the surface is perfectly
acceptable, and provides more surface tooth. The big secret is the
addition of two mordants to enhance and stabilize the colors. I usually
use salt and ammonia. The recipe I use most frequently is:
1 small piece of liver of sulfur,
about 1/4 inch in diameter
2 C. hot water
1 Tbsp. clear household ammonia
1 tsp. salt
Your solution should be a very pale straw
yellow color. If the solution is too strong, the colors will work too
fast. Add additional water if you need it. Iodized salt gives a
different effect than kosher salt, each intensifying certain colors the
other doesn't.
Now you need to set up your dipping
station, lined up in a row, so you can progress from one step to the
next, quickly and efficiently. You need a pot of very hot water and bowl
of very, very cold water. Your dipping station will be lined up in a
row, from left to right: pot of very hot water, hot liver-of-sulfur
solution, bowl of very ice-cold water. First dip your metal into the hot
plain water to warm up the metal. The warmer the metal is, the more
intense the effect and the more quickly the liver-of-sulfur solution
works. Then quickly swish it through the liver-of-sulfur solution, then
quickly put it in the cold water to stop the action. Do not leave the
piece in the liver-of-sulfur solution for any time waiting for the
colors to develop. The color will finish developing in the cold water.
Repeat until you get the colors you want. The color range is
predictable. First yellow, then green, red, blue, purple, and black. You
can have several different colors in one piece by selectively dipping
just one part of the piece.
Caution must be used with pieces that
have heat sensitive stones, or stones which cannot take thermal shock
well, such as opals. However, I've been successful, even with delicate
stones, by not getting the metal quite as hot when dipping and working
more slowly. I have used this process with pearls, turquoise, fire
agates, malachite, rhodonite, corundums and beryls, with no ill effect
to the stones. However, I would be reluctant to use the process with
say, a heavily included emerald, simply because the thermal shock could
cause the emerald to fracture.
After you have achieved the colors you
want, wipe the metal dry with a soft cloth. Allow to continue drying for
several hours. If you wish at this point, you can "knock-back" the
patina on the high points with a little rouge on a felt buff, so you
have the contrast of the bright silver against the color. Clean the
metal again, and apply a high quality wax, such as Renaissance Wax, or
cabinet-grade lacquer. Wax will dull down the colors a bit, and lacquer
will brighten the colors a bit. For things that will be subjected to a
high degree of wear, such as bracelets or rings, you may want to
incorporate guard wires during the fabrication of the piece to protect
the patina from abrasion. However, on something like reticulation, where
there are natural hills and valleys, the valleys naturally retain the
patina, while the high points become bright and shiny with abrasion,
providing a very lovely contrast.
Hope you have fun playing!
To Contact the Artist or to purchase any
of her pieces:
Sterling Impressions
Katherine Palochak
PO Box 1355
Rawlins, WY 82301
(307) 320-3094
kpalchk@trib.com
