Polishing and repairing stones

Occasionally we will drop or damage a “semi precious” stone, and
find the stone is salvageable, though smaller. Of course the stone
never breaks leaving a straight line so we cut it straight edge
using a diamond blade on a tile cutting wet saw. The saw leaves a
reasonably smooth edge but does not match the high shine on the rest
of the stone.

Is there a process whereby we don’t have to buy any more equipment
to polish the sharp edges and bring the edge up to a high shine? We
have a Foredom tool and many abrasive wheels.

I’m sure the question will be what stones? All I can say is that
there are a tremendous variety and hardnesses.

Would appreciate your advice,
Jon

Do I properly infer that these are cabs? If all you want to do is
polish a flat side you can get diamond compound in various grits, use
it along with the special oil (although my preference is w/o, not so
slingy) and a suitably flat wheel on the flexshaft. Dop your stone
well.

If these are faceted, the same setup will work, although its
applications are much more restricted. I have successfully repolished
individual facets this way but it takes a really steady hand and a
calibrated wrist, more so on corundum than quartz. If you don’t get
back in the groove at each grit change, your single facet may become
two. This is for minor repair only.

For very light damage sometimes a white bristle brush can get the
job done. Advantage here is that while you may round off edges a
little bit, alignment is not so critical and on rare occasions will
work while stone is still set. Depends on the stone how nitpicky you
need to get.

Lapis is a pain.

Is there a process whereby we don't have to buy any more equipment
to polish the sharp edges and bring the edge up to a high shine?
We have a Foredom tool and many abrasive wheels. 

If you are just after a quick and dirty to make is look better than
just the saw cut; get yourself a pack of wet/dry sanding paper.
Depending on how clean your cut is, you start in the 200 - 400 grit
range, and just rubbing the flat on the paper (spritz it with water
from a spray bottle) on a known flat, smooth surface (I’ve got some
heavy safety glass shelving salvaged from an old entertainment
center, for stuff like this) until you get the saw marks gone. Then
you keep stepping up grits until you get to a pre-polish you can
tolerate (for most colored stones, 600 or 1000 is enough).

After that, depending on the stone, you can use tin oxide (white
rouge) if you want to go “old school”. Softer stones will gloss up
pretty well with stuff like Zam. Different stones respond to
different polishes (and polish applicators).

If you want to speed up the process, you can invest in a cheap palm
sander, and clamp it upside down in a bench vise. Just don’t use so
much water that it runs into the motor. You don’t need very much,
just enough to keep the stone from dragging on the abrasive paper.

Ron Charlotte – Gainesville, FL

Do you have a dremel? You could polish it with that. You can get
diamond polish from any lapidary supply company, that should work
just fine :slight_smile:

Laura

rubbing the flat on the paper (spritz it with water from a spray
bottle) on a known flat, smooth surface (I've got some heavy
safety glass shelving salvaged from an old entertainment center,
for stuff like this) until you get the saw marks gone 

That reminds me - if anyone everuses superfine abrasives like
micro-mesh or micron paper, you’ll know how fragile and temperamental
they are. Make sure the abrasive sheet is clean (preferably new) and
that the glass sheet is clean. Using oil or water, you can “float”
the abrasive on the glass, and get a perfectly smooth finish. The
liquid does a fairly good job of holding the abrasive in place, and
stops dirt getting under the abrasive and making it bumpy. This not
only gives you a better finish, it also makes the abrasive last a lot
longer.

Jamie
http://primitive.ganoksin.com

you start in the 200 - 400 grit range, and just rubbing the flat on
the paper (spritz it with water from a spray bottle) on a known
flat, smooth surface (I've got some heavy safety glass shelving
salvaged from an old entertainment center, for stuff like this)
until you get the saw marks gone. Then you keep stepping up grits
until you get to a pre-polish you can tolerate (for most colored
stones, 600 or 1000 is enough). 

You can even do without the paper. A slurry of loose grit on plate
glass works fine.

Al Balmer
Sun City, AZ

You can even do without the paper. A slurry of loose grit on plate
glass works fine 

Yes, yes you can. I do, in fact, for some of the odd shapes that
simply won’t work on the lap wheels. But for someone who just wants
to salvage a split bead or cab, and not do it all that often, loose
grit isn’t generally available at the home center or a nearby auto
parts store. Wet/Dry paper is.

Ron Charlotte – Gainesville, FL