Dear Steve, thanks for your interest. If “chamfer” was
electronically garbled to “campher”, no wonder you were puzzled.
I originally wrote “chamfer” - at least that’s what we call the
small angled surface that’s filed off a corner in Oz. I guess
it’s the equivalent of taking out that little ream of metal from
the tube ends of a hinge before you rivet it, so’s the rivet
won’t work free. Same with the inlay. Think of it as a funny
shaped rivet, and you’ve got the idea.
You are quite right in your second question: the chamfer is
applied to both sides of the host metal and widens the hole top
and bottom. The inlay metal (in your case, platinum) being
slightly thicker, is then able to be hammered and spread to fill
the chamfered angle so that it presses firmly onto and slightly
overlapping the host metal (your 14ct). No solder, just expanded
Your question about finishing was a good one and I noticed a
couple of recent posts on polishing platinum which covered the
territory better than I could.
How do I finish and polish platinum? Perhaps it would be most
useful if I answered this in context of finishing and polishing
this particular type of inlaying. Because the platinum inlay is
still a little raised above the surface of the 14ct, I file this
down to the level of the host metal, being careful not to file so
much away that I break through the filled chamfer. I do this with
a fairly fine file, sometimes a hand-file, sometimes a needle
file, depending on the size of the piece.
Because platinum is a “grabby” metal, tending to stick in the
file teeth, I usually “pin” the file with a piece of chalk. A
wipe or two with a piece of chalk reduces the tendency of
platinum to stick in the teeth of the file. Now that it’s
satisfactorily filed, I emery with a 1200 grit emery paper.
Platinum is more difficult to polish - I don’t have to tell you
that. However there is a little trick that I have found useful in
the prepolishing finishing stage. Even though I’m already using
quite fine emery paper (1200 grit), I take a scrap of the same
grit paper and rub it vigorously over the surface of my emery
stick that I’m going to use to emery finish the platinum surface.
In other words I rub emery against emery which gives me a much
much smoother grit to emery the platinum with.
Now I’m ready to polish. The purists will probably throw up
their hands in despair, but I simply use tripoli, then green
rouge, then red rouge - just as I do for gold, and silver (and
titanium for that matter). Getting the platinum down to the
finest emeried finish I can seems to solve any problems of
Another tip re inlay: If it’s a relatively small inlay, I simply
burnish it with a freshly polished needle (again, polished with
tripoli, green rouge, red rouge) after emerying, before finally
polishing with - you guessed it - tripoli, green rouge, red
Steve, I really respect what you guys know about technique and
design. I hope I haven’t oversimplified or too-obviously spelt
out stuff that you may already know and do. Hope this helps. Let
me know if I can clarify further, Regards, Rex from Oz.