Carbide tipped can slam into the stuff & smash it to smithereens.hrmmmm reversed.... that might work
I used a fine tooth blade but my saw was not adjustable speed so it went to fast and would bounce it to splitting or breaking when I tried....
A fine tooth (untipped) works good.
DH uses masking tape along the cut on both sides of the cut to prevent splitting.
He uses a little hand-held thingy that has about a 4" circular blade on it....cannot remember what it is called.....................
