How can I turn Granite?

["moonsong" <moonsong@zzzzzzzzzzzzzzz>]

Jack,

I use the diamond saw for shaping the outside as well as the inside of
bowls- set the cutting line at a tangent to the desired circle, and rotate
the workpiece into the blade. Trim a small amount at a time, lowering the
blade after each complete rotation. Shape the outside first, then turn the
bowl over and shape the inside last.

If the saw is firmly fixed, the turning is much easier. A friend of mine
held an angle grinder against a piece of granite spinning in a wood lathe,
but I wouldn't recommend it! Worked for him, though! I've used a vertical
drill press with an adjustable turntable for turning pieces- set a steel rod
at each end of the workpiece and passed the top rod through a bearing plate
clamped to the turntable. The top end is held in the drillpress chuck jaws,
which spins the piece. The piece is shaped by a small grinder held against
the workpiece.

I used the vertical drillpress to horizontally mount a diamond saw blade,
followed by honing & polishing stones mounted in a water swivel. This was a
good way to shape, hone & polish small granite bowls with flat bottoms,
after they had been shaped internally with diamond core drills.

Simon
http://www.bn.tafe.net/stone/