Something I recommend doing is saving the slurry created while lapping your stones (the ones that work best with slurry or course). I read a post awhile back that spoke of this and I thought it was a great way to preserve unnecessary wear on finisher stones especially.
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This is slurry salvaged from lapping a Coticule I bought today at a flea market. It was laying in a cabinet underneath a sword of some type.
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