Kadonte,
I recently installed a polyurethane cutting edge on my rear blade. During this time of year, I use this set-up to remove snow from my driveway. The major portion of the drive is old pavement and one section is gravel. So far this season, the new edge had performed much better than the regular metal cutting edge on both surfaces. The polyurethane I'm using is one inch thick and does not penetrate into the gravel section. However, there has been a small amount of uncompacted surface stone picked up during the process but nowhere as much when using the metal edge. I'll try to remember to look up the address and pricing info at work and re-post later. Thanks Rick