Chris (and others who are interested in lapidary work with
glass): You can cut, facet, grind, polish, etc. glass just as if
it were stone. (Depending on the kind of glass, it is usually
somewhere between 5.5 and 7.0 on the Mohs scale.) The technical
glassworking term for this is “coldworking”. However, you must
use diamond equipment for sawing or grinding, and/or silicon
carbide as a grit on lap wheels for polishing. And you absolutely
must work with water as a lubricant. Unlike stone, glass will
fracture from the heat buildup of cutting, polishing, etc., so
the water is not just a lubricant, but a coolant. Oil will hold
the heat too much. Usually people who do this kind of work use
special equipment designed for working with glass. You can’t do
it on a regular buffing wheel, and compounds which will polish
metal or some stones generally won’t work on glass.
If you just want to work at the scale of glass cabachons, then
your easiest, cheapest option would be to invest in a set of hand
held diamond sponge pads available from Wale Apparatus (Phone #
is 1-800-334-WALE). These are called “diamond handpads”) and come
in grits from 60 to 1000. These pads are made in finer grits than
1000, and Wale may now carry finer ones; but if not, try some of
the lapidary companies which advertise through Lapidary Journal.
(In one of the issues this past summer, some of these handpads
were shown on the back cover in an ad for a company which carries
this kind of stuff.) Companies which carry stoneworking equipment
for headstones and stone sculpture also carry these pads. Expect
to pay $15 - $20 per pad, depending on the grit size. You can
also buy diamond “files”, which are little miniature pads on
plastic sticks, and these offer you a lot more hand control, but
for the money, your sponge handpad will last a lot longer. The
diamond wears out pretty quickly. (The files also don’t come in a
lot of grit sizes.) Don’t forget to work completely under water.
It isn’t enough to just have the piece a little moist. You won’t
break the glass if you’re grinding dry by hand, but you will
trash the diamond pad. As far as attaching your cab to something
so you can handle it, you can try dopping wax, but I don’t know
the temperature this needs to melt, and any abrupt temperature
change could thermal shock the glass. I think there are things
like chunks of shellac which can be stuck on and then dissolved
later in denatured alcohol. This would be your safest bet. I have
simply hand-held the things I’ve ground with pads.
If you’d like to try a mechanical method of grinding and
polishing and don’t want to spend a lot of money, Arrow Springs
(Phone # 530-677-9482) carries an inexpensive beveling machine
which comes with several wheels. I think it sells for between
$150 and $200. However, it may be difficult to get a cab with an
evenly domed surface by machine; the machine would be much more
suitable for faceting.
If you have a kiln and can get your cab to a decent surface
without scratches (e.g. 600 grit) by mechanical means, then you
can also bring it up to a high shine by fire polishing (don’t try
this with a torch; you’ll break the glass). If you’d like more
info about this, email me and I’ll go into more detail.
I think I saw Bob Aurelius’ name floating around Orchid - he
does a lot of glass faceting and working with large glass beads
like Maybe we can coax him out of hiding to tell us
more. I do a limited amount of coldworking, so am not completely
familiar with all the equipment options on the market.
Hope this helps (and isn’t gobs more than you really wanted to
know . . .)
Rene