Lead crystal polishing

can anyone help with lead crystal polishing - balls about 3 inches
dia. i get it to just about there with cerium oxide but need that
final clarity.

i have heard about a mixture of acids that could help but need some
expert advice?

Hi there. I taught a workshop last year and concurrently with it was
a telescope making workshop. They used the ceriumoxide and a lot of
elbow grease but as some point they sent it away to a lab… but
those were for telescopes and far more polished. My tangential point,
though, is that these were all a bunch of physicists playing in their
free time. If you’ve access to a university system you might ask
these sorts of fellows for ideas

50,000 and 100,000 diamond grit? Might help but I’ve never tried it.
Might be worth considering though.

Kenton Stevens

Have you tried optical grade cerium oxide also known as French
cerium oxide? What are you using to polish with? Try cerium oxide on
split cowhide. If that doesn’t work try tin oxide on split cowhide.
Try both on a moist muslin buff. Try mixing the cerium oxide with
petroleum jelly and buff with a muslin buff. Make a wooden wheel that
will fit on a tapered shaft and try it with cerium oxide, tin oxide,
or diamond paste. When I have a stone that just won’t take a polish I
just keep trying different things or combination of things.

Rick Copeland
Silversmith and Lapidary Artisan
Rocky Mountain Wonders
Colorado Springs, Colorado
rockymountainwonders.com

Angela’s email about physicists playing with mirrors for telescopes
really brought back memories of the days when my husband (a
physicist), would get together with his pals to polish mirrors for
telescopes. If I remember correctly they used powdered rouge and
chamois —the stuff was red. I believe that after they finished
polishing the big round slabs of glass they sent them to a lab to be
silvered. Polishing was a long painstaking job but they loved every
minute of it. They really got a good shine before the glass was sent
out to the lab.

Alma Rands

50,000 and 100,000 diamond grit? Might help but I've never tried
it. 

50K or 100K grit will only scratch glass. If CeO is not giving you
the desired finish, you’re using it incorrectly.

Wayne Emery

I polish some glass for a collector. I work it like an agate. I
finish polishing on an almost dry leather with cerium and it comes
out nice.

Larry E. Whittington
http://www.jewelrycabs.com

Along these lines, I found some (very old) red powder labeled “ruby
powder” amongst my studio effects. Does anyone know its uses?

If I remember correctly they used powdered rouge and chamois 

That was probably cerium oxide as it is the preferred glass polish.

Rick Copeland
rockymountainwonders.com

The ‘ruby’ powder is probably crushed synthetic corundum and is used
for polishing certain stones. Linde A is pretty much the standard
for alumina.

KPK

hey yall

just found a method to polish lead crystal glass found it in united
states patent files no 3290193- its with Sulphoric acid and
hydroflouric acid quite a labourious process