The official definition of the grit levels of sandpaper
goes something like this:
280-320 extra fine
360-600 super fine
The highest number I've found is the 600.
But in several references to waterstones I've seen
the numbers 1000 and higher, maybe even
3000. If this is on the same scale as above,
it would imply that the waterstones are much
finer than "super fine". Can this be right?
My question is: Is the same grit scale applied to
waterstones and sandpaper or do waterstones
have their own scale?
The reason I'm asking is because I'm considering
trying to sharpen my tools with sandpaper (the
Scary Sharp method).
Mr. or Ms. Sap
I use the scary sharp method.
The finest wet/dry paper I can find in this area is 1500 grit.
I think it is used for dulling car finishes before repainting.
This works very well for softwoods and okay for oak or maple.
It probably would not produce a sharp enough blade for the harder
woods (which I have never used anyway).
What bugs me about stones, besides the price, is that you have
to do maintenance on your maintenance tools (flattening the stone).
Sandpaper can just be thrown away.
Just my opinion
On Tue, 15 Jun 2004 10:47:12 -0400, "Zaster Sap"
1500 works just fine for sharpening edge tools for use with the harder
woods. In fact, many folks I know, who produce excellent work, generally
stop at 800.
I happened to run across an article in FWW written in the mid 90's by James
Krenov, on hand plane tuning. He indicated that, although heresy by then-
current dogma, he sharpened his planes with three levels of oil stones, and
a little kerosene. His finest grade of stone was a hard Arkansas, if
memory serves me. That's what I use on my kitchen knives.
My planes get taken to 800 with Scary Sharp, unless the project is at it's
final stage. Then 1200. Maybe.
Last project with 'harder woods' was, in fact, a plane body, with a base
plate of Jatoba. The one before that, Cocobolo. The plane blades were
just fine at 1200.
"if it's good enough for Jim, well, then, ..."
I understand waterstones and diamond stones do have different scales
and they don't cross exactly.
I use scary sharp on my planes and they are sharp, it's easy to do.
But the experts (jay greer, Steve Knight) say waterstones will get you
Same grit will give you the same scratch size, which is what sharpening is
about. Waterstones might get you there faster, powered waterstones faster
still. Speed counts more as an end to a sharpening cycle than as a hone
Stropping gives you the finest scratches, not honing. Not sure -
meaningless anyway - what "grit" it is, but Chromium Oxide compound makes a
fine strop, with powered strop more rapid than manual.
Unfortunately, waterstone grits do not compare directly to sandpaper
grits. Sandpaper can even be graded with different scales.
"There is little disagreement that one should sharpen to at least P800
(for comparison, a 1000 grit Japanese water stone equals FEPA P800 and
CAMI 500 in abrasive sheets). Not everyone agrees how much beyond P800
is necessary. As a point of comparison, a 6000 grit Japanese water
stone is equivalent to CAMI 1500 abrasive paper which is a third the
particle size of FEPA P2000 paper. Some people recommend continuing to
P2000 in abrasive paper and then stropping, while others stop at grits
coarser than P2000 and then strop."
Somewhere out there are comparison charts between the stone grades,
American sandpaper grades, and European sandpaper grades. I don't
have time to track it down right now.
You are, of course referring to the meaningless numbers, rather than the
actual grit, I take it?
Same grit - same scratch, regardless of how produced. I think we get hung
up an awful lot on the micrometer business, when we ought to be result
As others have mentioned paint and automotive stores carry much
higher grits than that. Also, Lee Valley has PSA-backed 3M
microfinishing film in 15, 5 and 0.5 micron which are supposedly
equivalent to 1000, 2500 and 9000 grits. I don't know if they are
equivalent or not, but I do know that I've been using the film for
several years now, and my edge-tools seem to be sharper and to hold an
edge better than when I was just using plain old SiC wet-dry paper.
I attach the film to granite surface plates and keep it out on my
old modified w*rkm*tt, so it's just a matter of taking a few steps
over to the bench to touch up an edge.
There are also some other companies online that sell a variety of
films, etc. Precision Surfaces International
(http://www.psidragon.com /) is one I've dealt with, and there is
another company that's even cheaper, but I can't seem to find their
site right now.
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