Magnetic mounting rubber and rigid mounting rubber used for washing out polymer plates come pre-sealed. Over time, this seal breaks down during the water washout of the platemaking process. You can make touch-up repairs with our green die sealer. Apply green die sealer in a thin bead to the edge of the mounting rubber so it overlaps the rubber and your mounting surface. Let dry overnight. We recommend you purchase this with your mounting rubber panel to properly maintain the mounting rubber and increase it’s usage and lifespan. 8 ounce bottle. Used in the Boxcar Platemaking department.