Finishing
PMC
can be:
*soldered.
tumbled *wire-brushed *enameled *plated* patinated *burnished* pickled
*sandblasted
*polished *left as fired
Soldering
As
mentioned, PMC is metallurgically just like other metals but structurally
a little more porous. It can be joined by using the same flux, solder
and torches as silver and gold, but because of its porosity, PMC will
"soak up" solder. When possible, prepare an area to be soldered
by burnishing to close the pores and reduce the tendency to absorb solder.
Even then it's important to use a delicate hand with the torch, removing
the heat as soon as solder starts to flow.
Of
course even in conventional metal, fine silver and gold behave a little
differently than their more familiar alloys, so care and attention is
recommended when first soldering Precious Metal Clay.
Because of its porosity, PMC objects can retain pickle unless they are
thoroughly rinsed. Neutralize the acid by boiling the pieces in a dilute
solution of baking soda and water or by cleaning them in an ultrasonic
machine for about 15 minutes.
Perhaps the most obvious option for finishing is to leave the PMC with
the finish achieved in the kiln. In a piece that will be rubbed
during wear such as a ring, the raised areas will be burnished naturally
while the recesses remain white (silver) or yellow (gold), To polish to
a high shine, the metal should be burnished, either by hand or through
mechanical polishing. Magnetic polishers, in which small rods and spheres
of steel are tossed against work by rotating magnets are ideal because
of their speed and ability to polish without damaging the surface.
To burnish by hand, use a steel burnisher
to rub the surface smooth.
After washing with soap and water, the final polish is achieved with rouge
applied by conventional wheels and polishing machines.
Silver PMC can be oxidized with liver of sulfur or a proprietary colorant
just like conventional metals. Pure gold is very difficult to color in
this or any other form, and will require commercial solvents, paint or
plating.
