Any suggestions no how to repolish the point of a carbide
burnisher. I must have rubbed a diamond facet or !
You need diamond compound.
Ideal is either a proper lapidary setup with diamond polishing
wheels, or something like a GRS powerhone with it's diamond grinding
wheels for shaping, and the ceramic wheel with diamond compound for
Barring that, you can make a small wooden wheel for use on the flex
shaft that works very well, but slower. Cut an 1/8 inch slice of one
inch wood dowel, and drill a hole in the center so you can mount it
on a standard mandrel such as you'd use for rubber wheels. True it up
so it spins flat and true, then, if you like, carve into one surface
slightly with a bur as it spins so it's got a slightly concave flat
surface on one face. Put a tiny dab of 14 thousand diamond paste
compound on that surface, and polish away. the concave surface
somewhat better fits the slightly curved bullet shape of the
burnisher point, and reduces the speed at which the compound is
thrown off. The wheel gets better as you use it, and needs recharging
only rarely. If you want an even higher polish, make another one for
fifty thousand compound. Initial shaping can be done with a small 600
grit diamond wheel. Crystalite makes a number of them that will
mount in a flex shaft. use them with oil or water, not dry.
An alternative that's simpler are the diamond charged rubber wheels
one can get marketed in particular for use with platinum. German
made. the green medium grit ones will leave a fine scratched finish,
roughly like a 1200 grit wheel, the grey grade will take that to a
reasonable polish, and the pink ones take that to a high polish. The
downside to these wheels are their cost, and their small size which
makes it harder to get a nice smooth finish on the burnisher instead
of a slightly wobbly or facetted finish. But they do work well to
polish the carbide, and at high speeds, are just killer on platinum...