I've recently started using fiberglass on my Pepakura projects, and I need to find out how to clean them up, and more importantly, in a safe manner. My grandfather, whom I work with my projects on, is extremely safety-consious and doesn't want to clean up my peps with his dremel, and other power tools, until he can verify that it will be safe. He is concerned about the tiny fibers being drilled off would damage his lungs, and that wearing a dust mask and goggles isn't enough protection. Any tips? Also, do you need a respirator when applying Bondo?