The hardware store here have only 600 Grit and 1500 Grit sandpaper. From lapping info I got it's usually from 400-600-800-1000-1500-2000 Grit but those are not available for me here. Can I jump from 600 to 1500 or should I use 1500 until the bottom smoothens out? I'm going to lap a thermaltake volcano 12. I asked this at the cases and cooling and didn't get any response. Any help would be great. I'd like to maximize the cooling of the cpu coz I'm going to overclock it.