"Ed Huntress" wrote in message
...

"Paul K. Dickman" wrote in message
...

In lapidary circles, there is a machine called a vibrating flat lap. It
consists of a big metal pan and plate mounted on springs with a motor and
an eccentric weight .
It would probably flatten a hard Arkansas stone pretty readily.

'Sounds good, if you have one of those tools. I'm curious, though, about
what happens when you use the traditional emery-cloth method with Arkansas
stones. Maybe I'll try it with one of my old slips, just to see.


It should do something, quartz has a mohs hardness of 7 and emery is a 9.
The only problem I see, is that dressing a india stone is like dressing a
grinding wheel, you just have to break the bond not the abrasive.
Cryptocrystaline quartz is bonded a little tougher.

Worst that would happen is that the only thing you'll acheive is cleaning
the surface.
Any serious flattening would be a a lot of work, though. Starting with a
diamond stone be a big help.
I have sanded a lot of quartzes and can tell you from experience, it is a
lot of work to remove even minor imperfections by hand sanding.



As a side note, I was taught to never use oil on one of these, it just
clogs the surface. Always use water. If I had to clean oil out of one, I
would probably boil it in lye.

The stories about sharpening stones and how to use them seem to have a lot
of variations. I've used honing oil or straight kerosene on mine for
decades without any clogging. I just flood them after use and wipe them
off, as I mentioned. I've been told never to use anything but light oil or
kero on oilstones, including novaculite stones, so I guess there's someone
around to tell you anything.


Ha. Probably true. I learned it from my father. It is his 8"x2" hard white I
have been using for the last 40 years.


BTW, I'd want someone else to try boiling in lye before I tried it on my
own stones. It's great for cleaning gun barrels before blueing but
Arkansas stones are mostly silica in the form of quartz, and an
alkali-silica reaction is well-known to attack and weaken silica. It may
be OK on the fairly nonreactive quartz form of silica, but not with my
stones, thank you, until somebody else goes first..

Geez, I'm not talking about dunking it in molten caustic potash.
Automatic dishwasher detergent would probably do a fine job too.

Paul K. Dickman