It’s not enough to simply learn the working differences between
platinum, gold and silver; you want to understand the strengths of
each metal and for what sort of design each is appropriate.
Platinum has three great virtues over gold and silver: it does not
oxidize, tarnish or get firescale; it is tougher and more abrasion
resistant than gold or silver; and it is a poor conductor of heat.
Because it is a poor conductor of heat you do not heat the entire
piece when soldering, but concentrate on the joint. And because it is
a poor conductor of heat, you can create a piece with multiple joints
without worrying that each new solder operation will undo the
previous ones.
Because it never oxidizes you can pre-polish all interior surfaces
and not need to use a boric acid coating when soldering. If a surface
is bright before it goes into the flame it will be bright when it
comes out. Also, flux is unecessary, and the wrong kind is
detrimental. To stick the paillons in place you can use spit, as has
been suggested, but you can also use a little Barrett’s flux. That’s
the typical green self-pickling flux; it won’t interfere with the
platinum solder.
Because it is tougher and more abrasion resistant than gold or
silver, you can use thinner material in construction than otherwise.
Prongs, hinges and hinge wires, jump rings, and chain links can be
thinner.
Things like which solders to use, which abrasives and polishing
compounds to use, what to use to support or manipulate the piece in
the fire, etc,. is the sort of knowledge your teacher will provide.
What he can’t provide is a feeling for the metal, which is why the
design is so important. If students are allowed to design their own
pieces the designs may not take advantage of the virtues of platinum,
and so you’d not learn how to design for the material’s full
advantage nor get a feel for how it works it in such pieces.
I’d suggest three projects which will highlight platinum’s strengths
and difficulties.
First I’d have the students make a simple solitaire ring with a
four-prong setting and a forged shank. After making a piece like
this in silver you’ll see how much easier soldering is in platinum.
Then I’d have them make a short length of delicate chain. The sort
of chain which you’d never make in silver because it’d be a pain in
the, um, neck and because no one would pay enough for a chain like
that in silver for you to recoup your labor costs.
Last I’d have them make an articulated piece with multiple joints.
An inline bracelet, also called a tennis bracelet, is an excellent
project. If has many joints and parts, but since each element is
identical to the others, excepting the catch, even if the first link
is not perfect by the time you get to the last you’ve had a lot of
practice. Making a tennis bracelet in silver is very challenging, as
there are so many joints and hinges close together. But once you’ve
done one in silver the benefits of making it in platinum become
glaringly obvious.
BTW, making an inline bracelet of this sort is a standard project
for second year jewelers at FIT here in NY.
Just my two cents.
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