Re: Drilling cabs
A technique that was shown to me by a turquoise dealer who was making beads was to take a small glass dish with straight sides. A votive candle holder works. Cut pieces of stiff sponge to fit the dish in enough pieces to bring the sponges level with the top of the dish.
Fill with clean water while the sponges are in place. The sponges will absorb a lot of water but give a fairly firm support for the stone to be drilled. Set your stone on the sponges and press it down until the water just flows over the stone and start drilling. The sponge holds the stone in place and supports it so there is not so much breakout when the drill bit goes thru.
Diamond bits are necessary as is the movement of the bit in and out to allow water to circulate in the hole to cool the bit and the rock. Failure to do this will ruin a plated bit in seconds and a sintered one in minutes.
Good luck on your drilling project.
The Amethyst Rose
From Bob Johannes - April 30, 2008 at 13:29:20