Thread: Black Diamond hone

Originally Posted by pommyphil

Should this be in Sharpening

Done

Originally Posted by pommyphil

I've just unearthed an American Hone Co. Olean, NY. USA Black Diamond

artificial stone 130X50X12mm [5"X2"X 1/2"], unsuprisingly it's black

It's very fine and looks unused. Would anyone know if it's a water stone or an oil

stone ? How could I tell ? Would it harm the stone to get it wrong ? Should this be in

Sharpening

I don't know if it is water or oil. If it has been used with oil in the past, a few drops of water will bead up. If it hasn't been used it may not hurt to use either. Pictures may help.

ron

Thanks Ron. In the cold morning light it's clearly not a virgin, as often happens

I think oil can stuff up the bond in some water stones, they turn to mush.

water would probably be safe on a oil stone though, maybe ? Phil

Water can work on an oil unless the stone has had oil on it before. If the stone has had oil on it previously, the water will just bead up on the surface and not accomplish anything. The purpose of the liquid (whether oil or water or mineral spirits or whatever) is two fold. It provides some lubrication. And it keeps the abraded material from clogging the stone which keeps the stone wearing away the metal. (It doesn't actually cut the metal.)

As I don't use water stones, I don't know the effect oil may have on them.


ron

Looking at your photo and I think the biggest clue there is the small chip (A few of mine have a similar chip), that along with the dimensions you've given brings me to think it's what I've always known as a India Rubbing Stone.

So it's an oil stone but it will give you a very fine finish - Not a polished as a 8000+ grit waterstone but certainly good enough to give you a very good working edge.