Some years ago I built what I thought was going a totally slick 
sharpening rig.  Three Glass plates and a leather strop the plates were 
20" long 4" wide and 3/8" thick

I got some diamond grits for it.  they were the wrong grits. Too fine. I 
really didn't know  much about the  sizes of diamond grits.  Still don't.

I got half,  one, and two micron. They don't seem to make a dent in an 
edged tool.

What three grits would you choose ? Assuming you  know more about this 
than I do.

Know a good source?

Cliff -

Lee Valley sells diamond lapping film in a variety of grits.  The grits
they offer are 15, 3, 0.5 and 0.1 micron.  They aren't too dear and would
be a way to try those grits and see if they do the job for you without
selling your first born.

http://www.leevalley.com/us/wood/page.aspx?p=68943&cat=43072

Free shipping at the moment, too.

Phil

On Tue, May 23, 2017 at 9:26 AM, Cliff  wrote:

> Some years ago I built what I thought was going a totally slick sharpening
> rig.  Three Glass plates and a leather strop the plates were 20" long 4"
> wide and 3/8" thick
>
> I got some diamond grits for it.  they were the wrong grits. Too fine. I
> really didn't know  much about the  sizes of diamond grits.  Still don't.
>
> I got half,  one, and two micron. They don't seem to make a dent in an
> edged tool.
>
> What three grits would you choose ? Assuming you  know more about this
> than I do.
>
> If I am not mistaken, those are polishing grit numbers.

My power sharpening rig has 1200 grit paper, which I think they claim is 6
micron, which really just polishes.

So yours are REALLY fine.

-- 
Kirk Eppler in Half Moon Bay, CA

Cliff

DMT has a chart for their diamond stones:

https://www.dmtsharp.com/sharpeners/bench-stones/duosharp/

you need to click on the [View DMT Grit Chart] button to see it. It says

120 micron = 120 mesh = silver
60 micron = 220 mesh = black
45 micron = 325 mesh = blue
25 micron = 600 mesh = red
9 micron = 1200 mesh = green

Each stone has a colored dot on it, and the colors are just a
nomenclature for DMT.

I have the last four diamond stones on the above list. When sharping a
tool found out in the wild, I typically start with the black stone to
flatten the blade as quick as possible, skip the blue, because
honestly it doesn't see to be much different than by black (or perhaps
the black stone is worn out). Then I go to red, green, a 1000 grit
water stone, 4000 grit, then 8000 grit. So in other words, if you want
to deal with powder, 60, 25, and 9 micron.

If I remember correctly Leonard Lee wrote a book called the "The
Complete Guide to Sharpening" with a chart that converted microns to
grit size.

Thank you,
Chris

On 2017-05-23 12:04 PM, Kirk Eppler wrote:
>> I got half,  one, and two micron. They don't seem to make a dent in an
>> >edged tool.
>> >
>> >What three grits would you choose ? Assuming you  know more about this
>> >than I do.
>> >
>> >If I am not mistaken, those are polishing grit numbers.
> My power sharpening rig has 1200 grit paper, which I think they claim is 6
> micron, which really just polishes.
>
> So yours are REALLY fine.

There are so many standards of grit it's almost impossible to discuss 
them without specifying a reference.

I'm not certain of this, but I don't believe you can directly compare 
the effects of high speed vs hand speed grinding or sanding with a 
particular grit. Size matters, but so does speed!

Finally, consider this sharpening schedule which uses 15, 5 and 0.5 
micron paper to form 3 microbevels.

http://www3.telus.net/BrentBeach/Sharpen/3m.html#my

IME, The two finer grits don't just polish, they hone very narrow 
microbevels. On a larger surface, it might just seem they were merely 
polishing.

FWIW
Don, taking a break from the garden





-- 
The harder they come, the bigger they fall - Ry Cooder

Don Schwartz engaged us with:
>I'm not certain of this, but I don't believe you can directly compare 
>the effects of high speed vs hand speed grinding or sanding with a 
>particular grit. Size matters, but so does speed! I am not a grinding expert,
but have done a fair bit and understand this to be correct.

Other things that matter include how the grit is bound (binder type and
hardness), the sharpness of the grit, the hardness of the grit, and the density
of the grit in the binder. I have achieved near mirror finish with wheels of
120grit under the proper circumstances (slow passes and very light cut), needing
only final finishing. I believe that it is roughly (pun intended) the number of
points presented to the work in the desired plane, not the actual grit size, and
a properly dressed course wheel presents many, many points in precise relation
in a short time.

*** This message was sent from a convenience email service, and the reply
address(es) may not match the originating address

Hi Cliff,

On 23 May, Cliff wrote:

> I got half,  one, and two micron. They don't seem to make a dent in an edged
> tool.
> 
> What three grits would you choose ? Assuming you  know more about this than
> I do.

I wouldn't assume that, but I've previously tried 45 micron diamond
compound placed on an iron plate for flattening the backs of chisels and
plane blades.  I remember it working just 'OK'.  It was slow and I
eventually switched to the blue zirconia alumina belts, but to be fair
some of the blades I was working on then were in fairly rough shape.

On something like a blade bevel, I expect that size grit would work well
for initial sharpening of a newly-ground edge and probably for removing
small nicks, but I've not tried it for that.

> Know a good source?

I got mine from Tools for Working Wood.  That was probably 10 years ago
or so, though,  and I've not shopped for any diamond abrasives since
then. 

There's an older Amplex Abrasives (now owned by Saint-Gobain) catalog
here:

www.efqinc.com/pdf/AbrasivesAmplexCatalog2008-2009.pdf

that provides brief information about available grit sizes and
applications for diamond compounds.

Regards,

Norm
  - Madison, WI

On 2017-05-24 8:09 AM, Norm Wood wrote:
> I've previously tried 45 micron diamond
> compound placed on an iron plate for flattening the backs of chisels and
> plane blades.  I remember it working just 'OK'.  It was slow and I
> eventually switched to the blue zirconia alumina belts

I haven't tried the diamond compounds, but the blue zirconia belts glued 
to 1/4 inch glass are tremendous for flattening chisels. I'm using 50, 
80 & 120 belts. They last and last. Just vacuum off the swarf from time 
to time.

FWIW
Don

-- 
The harder they come, the bigger they fall - Ry Cooder

Cliff is asking about edges…

Some good info about diamond grits and suchlike.  All very relevant to the
question, but I’d just like to weigh in with my usual mantra of ‘sharp enough’

Now, I know some folk have a singleminded pursuit of sharpness, and going down
to a half micron level sounds as if it will yield me a blade to split cobwebs.
The thing is, of the woodwork I do, there’ may be only ten minutes of needing a
blade like that in the course of a half a week of making.
The great, maybe revolutionary, idea behind using glass and replaceable abrasive
sheets is the time it takes to get from too blunt for the job, to way past sharp
enough so you can get back to work.

Most of my sharpening regime is based around a rotating wet stone to give a
hollow ground, and a quick touch to a fine carborundum stone - which I have
always used only with water.  A pass over the back, and a strop to remove the
wire edge, if any, and back to work.  As the blade dulls, a refresh on the stone
is quick, and back to work.  For the final clean up on something tricky, then I
may turn to some fine compound on an oak bound leather strop - 10,000 and
15,000,  and there are a couple of planes set up with their blades honed this
way so that work isn’t interrupted.

If sharpening isn’t the object of your tie in the workshop,  I’m merely saying
that there is a seduction in sharpening to a half micron mirror finish which is
detrimental to output.

Wait - did I suggest that we’re meant to be turning out finished items?  Ooops,
sorry, pass the spittoon.


Richard Wilson
Yorkshireman Galoot 
in Northumberland

what Richard Wilson said.

  that said, once I started shaving with straight razors my attitude
toward sharpening changed, or maybe just the goalposts did. I mean,
sharp enough for woodworking, even delicate cross grain work in
squishy soft woods is dull enough to leave your face on fire after a
shave. really put the pressure on to up my sharpening skills. good
enough for chisels and planes isn't good enough for razors. but I'm
still after good enough for the application at hand, and the most
efficient way of getting there.

Bridger, who just ordered some 0.3 micron lapping film to deal with a
problem razor.

----- Original Message -----
From: "yorkshireman@y..."

To:"Cliff" 
Cc:"oldtools List" 
Sent:Thu, 25 May 2017 10:30:59 +0100
Subject:Re: [OldTools] open question: diamond grit

 Cliff is asking about edges…

 Some good info about diamond grits and suchlike. All very relevant to
the question, but I’d just like to weigh in with my usual mantra of
‘sharp enough’ 

 Now, I know some folk have a singleminded pursuit of sharpness, and
going down to a half micron level sounds as if it will yield me a
blade to split cobwebs. The thing is, of the woodwork I do, there’
may be only ten minutes of needing a blade like that in the course of
a half a week of making. 
 The great, maybe revolutionary, idea behind using glass and
replaceable abrasive sheets is the time it takes to get from too blunt
for the job, to way past sharp enough so you can get back to work. 

 Most of my sharpening regime is based around a rotating wet stone to
give a hollow ground, and a quick touch to a fine carborundum stone -
which I have always used only with water. A pass over the back, and a
strop to remove the wire edge, if any, and back to work. As the blade
dulls, a refresh on the stone is quick, and back to work. For the
final clean up on something tricky, then I may turn to some fine
compound on an oak bound leather strop - 10,000 and 15,000, and there
are a couple of planes set up with their blades honed this way so that
work isn’t interrupted. 

 If sharpening isn’t the object of your tie in the workshop, I’m
merely saying that there is a seduction in sharpening to a half micron
mirror finish which is detrimental to output. 

 Wait - did I suggest that we’re meant to be turning out finished
items? Ooops, sorry, pass the spittoon. 

 Richard Wilson
 Yorkshireman Galoot 
 in Northumberland

 > On 23 May 2017, at 17:26, Cliff  wrote:
 > 
 > Some years ago I built what I thought was going a totally slick
sharpening rig. Three Glass plates and a leather strop the plates were
20" long 4" wide and 3/8" thick
 > 
 > I got some diamond grits for it. they were the wrong grits. Too
fine. I really didn't know much about the sizes of diamond grits.
Still don't.
 > 
 > I got half, one, and two micron. They don't seem to make a dent in
an edged tool.
 > 
 > What three grits would you choose ? Assuming you know more about
this than I do.
 > 
 > Know a good source?
 > 

 ------------------------------------------------------------------------
 OldTools is a mailing list catering to the interests of hand tool
 aficionados, both collectors and users, to discuss the history,
usage,
 value, location, availability, collectibility, and restoration of
 traditional handtools, especially woodworking tools.

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 https://oldtools.swingleydev.com/mailman/listinfo/oldtools

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 OldTools@s...

Cliff

Loose diamonds only work if used in lapping - pressed into a surface 
that will hold the diamonds.

Someone mentioned a cast iron plate - that works.

Someone else mentioned a film you put on the glass into which the 
diamonds are pressed - that works.

Even the leather will work.

Putting diamond paste directly on glass will not work. Rolling grit can 
dent the tool surface, it cannot remove any metal. Picture somewhere on 
my web site.

There is one other matter that is important. It is not the size of the 
grit that matters, it is the density of the points. Fine grits make fine 
scratches only if they are densely packed and hence the number of points 
per unit area is large which means in turn that the force per point is 
small which means that the depth of penetration is small.

Spreading some diamond paste on a lap puts an unknown number of points 
per unit area, so the depth of the resulting scratches is unpredictable.

When I was looking at lapping I discovered that even a few stray bits of 
swarf from a prior step could scratch up the bevel. This is mostly 
because there are so few of them.

In summary, rolling your own stropping device produces unpredictable 
results.

Buying quality abrasives makes sense to me.

Brent

On 2017-05-23 09:26, Cliff wrote:
> Some years ago I built what I thought was going a totally slick 
> sharpening rig.  Three Glass plates and a leather strop the plates were 
> 20" long 4" wide and 3/8" thick
> 
> I got some diamond grits for it.  they were the wrong grits. Too fine. I 
> really didn't know  much about the  sizes of diamond grits.  Still don't.
> 
> I got half,  one, and two micron. They don't seem to make a dent in an 
> edged tool.
> 
> What three grits would you choose ? Assuming you  know more about this 
> than I do.
> 
> Know a good source?
> 
> 
> ------------------------------------------------------------------------
> OldTools is a mailing list catering to the interests of hand tool
> aficionados, both collectors and users, to discuss the history, usage,
> value, location, availability, collectibility, and restoration of
> traditional handtools, especially woodworking tools.
> 
> To change your subscription options:
> https://oldtools.swingleydev.com/mailman/listinfo/oldtools
> 
> To read the FAQ:
> https://swingleydev.com/archive/faq.html
> 
> OldTools archive: https://swingleydev.com/ot/
> 
> OldTools@s...
> .
> 

-- 
Brent Beach
Victoria, BC, Canada

In a similar vein, Dan's Whetstone's website says that the particle size
(3-5 microns) is fairly consistent across all grades of Arkansas
novaculite; it's the density of the particles that makes the difference -
harder/finer is more dense.

Steve in Kokomo