Forget the router. I have cut cultured marble with a sabre saw blade
that has carbide granules welded to the cutting edge. I am not sure if
they still make them. An abrasive blade in a skilsaw will make straight
cuts.

Mule-Tracks
One for the nail and two for the board.

Jon Wood wrote:
I have an old vanity top left over from my bathroom remodeling project. The
top has the sink built in and it is made of cultured marble. Can I cut out
the sink into a new oval shape and reuse it? I have a few non-carbide
router bits that I would be willing to use (sacrifice). But I was wondering
if anyone else has tried this.
Thanks for the help.
--Jon