"Joe Riel" wrote in message
Not woodworking, per se, but steel is steel and sharp is sharp.
My Wahl electric hair clippers were dull. I tried sharpening them with
waterstones; that didn't work, they then cut horribly (sound and fury,
very little cutting). I tried again, this time remembering to first
flatten the stones. The result was probably worse. After using the
finish stone, the center of the blades were noticeably shinier than the
edges, indicating the surfaces were now ground convex. Presumably this
was a result of the first sharpening, with a stone that was concave.
I tried once more, this time starting with a flattening iron and grit.
Progressed through the grits, then again used the water stones, paying
more attention to first getting them flat. After the finish stone, the
surfaces were nearly uniformly shiny, but one corner was sligtly dull.
This time the blades cut better; not ideal, but enough to do the job
(fortunately cutting my hair isn't much of a job).
I measured the diameter of a strand of hair, it is approximately 1.5
mil. That suggests the desired flatness for each surface should be
about 0.5 mil or better. A problem with using stones, etc, is that
there is no real indication of flatness until the final step, that is, I
can only observe a difference after there is a near mirror finish.
A few questions. Would I do better with sandpaper on a glass surface?
Is there a reasonable way to determine whether the initial grinding (at
the coarsest grit) yields a flat surface (on average)? What's the best
way to flatten a water stone? I generally just abrade it against a
reasonably flat section of concrete, check with a straight edge, and
finish by rubbing two stones against each other. That works fine for
chisel and plane blades.
OK, I've been watching here for a few days and no one's mentioned the real
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