drilling would be better prior to shaping,as you must use a diamond drill bit or core drill bit under water(rock and bit under water only!!!) a dremel or foredom with flex shaft a must.i have done this many times and works well,just go slow and at the end of hole go even slower to prevent breakout( chipping) good luck to you.......

From warren kruger - April 24, 2008 at 08:04:26
Email:

Message: 66433