Hi,
I've been into woodworking for a while; just transitioning to marblecarving.
An instructor gave me what seems sound advice that to polish the marble, rather than chewing through sandpaper, to use a water-based whetstone to grind and polish it smooth. In this case, you want small, skinny fragments, not to pay for new, flat, large whetstones.
SO-- in my quest for trashed stones to pick up dirt-cheap, what's the difference between a stone that requires oil, and one that requires water? I assume the oil-based are tighter-bonded, and will dissolve rapidly with water...? Or maybe they'll still work for my purposes?
There is, that I know of:
carborundum (gray stones) aluminum oxide (white or maybe grey, the cheaper ones) silicon carbide (green usually, probably the binder holding the particles in place) diamond
...then a slew of natural stones, the minerals of which I don't have a clue.
which need oil as a rule, which water, what governs this? How to tell when staring at a photo on ebay of 25 trashed honing stones all jumbled together?
thanks! -Bernard Arnest