Our shop uses 90 tooth Diablo blades from home depot to sawcut acrylic. If we did not have our cnc router, we would sand the edges smooth, as was stated earlier in this thread. We put the acrylic in a break (normally for bending metal). When it is in the break (with the paper still on), only the side of the acrylic to be polished is showing. This keeps the flame from hitting the face, or the backside. We have, in the case of large sections of acrylic, used metal plate, or bar, clamped to the face and back of the acrylic.