If you find your abrasives are not sticking to your backup pad, there is a good chance it is time to replace it. The hook and loop fastening system will wear over time, especially on the corners. The primary cause of this wear is the heat created from friction during the sanding process. Putting too much downward pressure on your sander creates excessive heat and causes the hook part to melt, shortening the length of the hook. You may want to order the longer J-hook and loop for your next replacement pad to try.