As Jeff said, it was mostly earlier particles, Columbia's in particular. They used little hollow beads of glass, which was pretty soft compared to sandpaper, Trizact, or Abralon. Sanding them could smooth out the particles and kill the reaction.
Modern particles don't really suffer that kind of problem, though, and they can be resurfaced without too much worry. You could always contact RG directly to be sure.
Edit: A teammate has an Oracle Vision that he's adjusted the surface on several times without problem.
SH
Edited on 5/5/2008 8:11 AM