Make sure you cut the top of the mold uppermost. Or as I have done to save chip out that tile saws cause make a shallow cut on the underside then cut from the top side. You need to have a variable depth adjustment on your tile saw of course. If thats not an option you will get chipp out but on most molds who care about the underside. BTW don’t use your glass blade to cut molds, dams or mullite shelves. The materials are softer than glass and a glass blade has a thinner kerf but can clog the diamonds.