George wrote:
"Never Enough Money" wrote in message
ups.com...
Excellent explantion. Thank you. It does, as you say, put high demands
on the holder: it must be dead nuts flat.


No, the tool holder must be a constant distance across the highest point of
the paper or stone. The Makita directions I mentioned refer to it when they
say take the edge off the stone and cut uphill by tilting the rest. Where
you've ground already needn't be a drag on the stone or grit, you're done
with it, and would rather it grabbed air.

The obsession with flat abrasives and holders is nice, but if you pass the
blade across a 1/16 wide jeweler's blade at a consistent distance, you'd get
a straight edge. Don't take the work away from the holder by pressing into
the stone, that's honing. This is still grinding.

Yes. I agree. I like the example of the very narrow abrasive. Still,
the tool-holder/blade/abrasive geometry must remain constant throughout
the grinding operation. The blade can be slid side to side, as when
you use a narrow belt sander, but the tool-holder must not deform.