Here is what I discover over the last 6 months. If I don’t keep a fresh pad (about 1 per panel) the product builds up. That is to say, the moisture content, keeping in mind that the products we use are water based. On small surfaces where the pad does not come in full contact, rotation stops (or slows) and only the orbiting takes place. This creates a lot of friction between the backing plate and the pad at the center of the orbiting action. Friction creates heat and the heat creates steam from the moisture of the built-up product. The steam will melt the center of the backing plate and hollow out the center of the pad. I have had melted foam between the pad backing material and pad surface before. This tends to happen mostly on irregular surfaces but I have had my pad begin to break down on flat panels. What I have done to correct this is to keep my pads washed out between panels. I use the WG pad cleaner, wash with warm water and Meg pad brush, wring out most of the water by hand without twisting, press between several layers of towels then mount on a 3” backing plate mounted in a drill motor. I run the drill wide open for several minutes to sling out as much moisture as possible and I now have a fresh pad for the next panel. I also stepped up to the Flex 3401 for this very same reason.