Flattening Oilstones
T
O FLATTEN AN OILSTONE, take a flat piece of plate glass or steel,
sprinkle about^1 ⁄ 4 cup of 80-grit carborundum powder (available
from any lapidary supply house) onto the center of the glass, and pour
about^1 ⁄ 4 cup of water into the grit. Grind the stone in a circular
motion, using as much of the glass surface as possible. Keep heavy
pressure on the stone as you grind. I always flatten the coarsest stone
first, while the grit is cutting fastest, then move on to the fine stones
as the grit wears. Check the stone with a straightedge after washing
the grit off and drying the stone with paper towels. After flattening
about a dozen stones, the glass itself will probably become slightly
hollow and must be replaced.
Waterstones are even easier to flatten. Some workers flatten them
by rubbing two waterstones together.You can also put a piece of
220-grit wet/dry sandpaper on a piece of plate glass, flood the paper
with water and grind the stone with a circular motion on the paper. If
you have both waterstones and oilstones, use different pieces of glass to
avoid contaminating the waterstones with oil. Wash the stone and
paper frequently by dipping them in a bucket of water, and dry the
stone with paper towels before checking with a straightedge.
The type of stone you use is a matter of preference. For years I
recommended a medium India, then a fine Arkansas oilstone as the
best method to get a good best edge. I now think the edges possible
with waterstones are even better.
—IANKIRBY,Cumming, Ga.,
from a question by Mark Pratt, Nickliff, Ohio
SHARPENING & GRINDING