Pool plaster diamond polishing pad 70 grit is designed to hone down semi-coarse-scale and quartz pool finishes. Used to polish Durazzo Polished Marble Pool Finish, Hydrazzo Polished Marble Pool Finishes, and Pebblesheen finish. All diamond pads use a corrosive metal for diamond bonding unless specified because of the cost. That causes rust problems from the residuals most of the time after use. Our diamonds are bonded with a NON-CORROSIVE material. The Pool plaster diamond sanding pad works on all pool plaster finishes. When using a pool plaster disc without water it is important not to overheat the disc by doing a 5 Ft. x 5 Ft. area and then using a hose to wash off plaster residual material remaining. This will keep the pool plaster disc and pool plaster from overheating. Excessive heat will cause a breakdown in the integrity of both pool plaster discs and pool plaster. Maximum 3500 RPMs. Our 7" diameter hook and loop backer pad AG7529 used with our Pool Plaster Diamond Pad 70 Grit ensures 100% contact with the pool plaster finish you are resurfacing. (using a smaller diameter backing pad will cause the pool plaster disc to wear unevenly and reduce its life of the pool plaster disc) Pool Plaster Polishing Pads. See our How To Repair Rough Pool Plaster page for more information.