Originally Posted by
HNSB
I've been told that you should never lap a stone with anything that has a grit finer than the stone being lapped. The smaller grit can clog the coarser grit stone. I don't know if you're lapping a 1k or less, but if so, definitely get rid of the 1500 grit sandpaper.
Also, like the others, I only lap or de-swarf stones with a single lapping stone which is a pretty coarse grit. (low 300's IIRC)