Wow. I'm a cabinetmaker, so I use alot of sandpaper.

80grit is like the pulverizer of death when it comes to wood. Harsh. I never would have guessed you work from something more coarse than that doing fibreglass work. Then again one of my poorly repaired daggerboards, (previous owner filleted one), was thicker than the other and I went to town on it with a beltsander and 120g to get it back down to thickness. That was a massive pain in the rear. I only got to sail once this year with fixed daggerboards. One of my boards looked like death, the other was mauled by a mystery pile of rocks in 10ft of water. They both sucked. Scared the crap outta me when the boat started humming in some serious high pitches after they were all fixed up. Apparently I didn't have any decent flow over anything prior to fixing them. Man I hate being lazy.....