Drilling alabaster

[Don Dougan <dondougan@zzzzzzzz>]

Hi Hap,

Though you can use masonry drill bits with carbide tips, a cleaner and
more accurate hole can be drilled in alabaster with a regular high-speed
twist drill bit at a slow speed.

Running the drill motor at a high speed will cause the edges to chip and
possibly cause the stone to crack -- if you have a variable speed drill,
adjust it so the speed is less than 200 rpm or so -- probably the lowest
setting on the trigger before the drill wants to stall.

Use a steady, even pressure, and clean out the hole by either withdrawing
the bit every fraction of an inch, or keep an air nozzle blowing surface
of the hole during the drilling operation.

Also, it will reduce the likelihood of splitting the stone if the hole is
several times the diameter of the finished hole away from any outer
surfaces or edges.  If your hole is more than 1/4" in diameter, using a
smaller pilot and then stepping it up to the final size in several stages
will help.

When I mount a piece on a pin, I usually figure as a rule of thumb that
the depth of the hole is approximately one-quarter to one-third the
overall height of the piece, and/or perhaps twenty times the diameter of
the rod used for the pin.

Good Drilling to You,

Don

http://www.dondougan.homestead.com/indexdd.html