Help, going to make a plaster of paris tool, but I don't know what the "EPOXY" is for, a water proofer or a means to secure the ceramic tile to the POP. So what kind of epoxy do I buy. Going to Lowe's Also should the tile be 1" sq. making a 8" mirror with 6" tool. Thanks in Advance Clear and Dark Skies Joe McCafferty 40-46-26N 79-58-01W