this may not be an easy question to answer in words but here goes nothing - I've seem what platinum can be polished to and i am useing the gesswin (4) polishing compounds and can not seem to get the same results, is there some trick i don't relise
First off, realize that a cast platinum object will never take
the same degree of polish as one made from forged or rolled or
drawn metal. One of the finest polishes I see on my platinum is
simply the drawn finish I get when I make wire, since I’m useing
highly polished carbide drawplates. That metal coming from the
plate is wonderfully polished, and compacted enough so that
after fabrication, it can again, with care take that same polish
again.
In general, it’s important with platinum to be sure each step is
complete. You need to start with carefully emoried surfaces,
usually taken out to at least 320 grit, and better still, 400 or
600 grit emery paper. Than, each step in the buffing and
polishing sequence must be done carefully enough to be
completely effective before moving to the next finer step. Take
no shortcuts here. Traces of the roughness from coarser
compounds or emery, not removed by the next finer compound, won’t
then be removed by the finest ones, so you’ll see a ripple, or
even a little haze, when you wanted a fine hard polish. Also,
which compound are you using for the final step? Gesswein’s
carrot compound gives a darker, harder finish than the 8000 step,
but isn’t as good at removing the last traces of scratches or
haze. Be sure the last buff you use isn’t contaminated either.
And you can also try a little red rouge or some green rouges as
well. The red in particular will not remove even tiny scratches,
but applied to an almost fine polish, can complete the “coloring”
step very nicely. A clean rouge buff is critical here, or you’ll
get fine scratches. And beware of using too much compound as
well.
If you’re continuing to get “orange peel” effects, even with the
gesswein compounds, you might need to burnish the surfaces.
Burnishing, especially with a carbide burnisher instead of a
steel one, will compact the surfaces nicely, and if done with
care, can leave a pretty nice surface all by itself. The
burnisher needs to be carefully polished itself, and being
carbide, need lapidary equipment (diamond polishing compounds) to
properly polish up. But once done, if cared for, it will last
well. Carbide burnishers are not widely available. You can make
your own by silver soldering a bit of old broken carbid circuit
board drill, or other similar bit of 1/8th inch carbide rod to
the end of a piece of steel (A gutter spike works nicely, and is
a cheap handle). Grind to a bullet shape and polish, using
lapidary grinding and polishing materials.
Hope this helps.
Peter Rowe