Sharpening question,

[Rick Fisher]

Any progress I have made in sharpening has been self taught after reading here. The recent sharpening thread was insightful to me, they always are ..

I use a Veritas jig for chisels and plane blades, my reason for not free hand sharpening is that I cant seem to repeat the same angle over and over ..

Anyway .. lately I have been sharpening the entire bevel.. Basically polishing it up to 13000 (sigma) and then stropping it.. Afterwards I do a micro bevel with only the 13,000 grit stone and the strop..

This is as sharp as i have gotten to date, but I know it could be better..

The micro bevel I create that way is microscopic. I ensure that the back is flat and the sharpening process leaves a burr after each stone.. but for some reason, I cant ever seem to really nail it ..

People talk about being able to shave with a chisel or plane blade.. I could do it but would have a few dozen blood soaked toilet paper spots on my face .. :)

I would love to take a class.. Or sharpen a chisel in front of some old timer, who could say ... " hey ! what was that ! " .. or give pointers..

Would love some videos or similar to watch..

[Steve Friedman]

There are lots of YouTube videos - I like the ones by Deneb at Lie-Nielsen. But, I think there's any easy fix - stop stropping after the 13000 stone! In my opinion, anything you do after the 13000 Sigma stone (except maybe Chris' hand stropping) will make your edge duller.

Steve

[David Weaver]

Any progress I have made in sharpening has been self taught after reading here. The recent sharpening thread was insightful to me, they always are ..

I use a Veritas jig for chisels and plane blades, my reason for not free hand sharpening is that I cant seem to repeat the same angle over and over ..

Anyway .. lately I have been sharpening the entire bevel.. Basically polishing it up to 13000 (sigma) and then stropping it.. Afterwards I do a micro bevel with only the 13,000 grit stone and the strop..

This is as sharp as i have gotten to date, but I know it could be better..

The micro bevel I create that way is microscopic. I ensure that the back is flat and the sharpening process leaves a burr after each stone.. but for some reason, I cant ever seem to really nail it ..

People talk about being able to shave with a chisel or plane blade.. I could do it but would have a few dozen blood soaked toilet paper spots on my face .. :)

I would love to take a class.. Or sharpen a chisel in front of some old timer, who could say ... " hey ! what was that ! " .. or give pointers..

Would love some videos or similar to watch..

Rick, there are only two things to be concerned with:
* the angle (geometry)
* uniform polish on both sides (and the level of polish)

Plane irons generally last best around 30 degrees or slightly higher. I know this has been a point of contention among some, but I have seen documentation this is true (and experience of the same) and no documentation stating less is as good for actual wear.

If you are around 30-32 degrees and you have a uniform polish all the way to the edge with the stones, there isn't much more magic to be had.

Shaving hair is one thing, shaving it effortlessly without having the edge touching your skin is another, and the latter is really what you'd want were you to shave your face.

I have used just about every synthetic stone there is short of the gokumyo that stu sells (but I have used the 30k shapton) and there is no synthetic stone that I use that I like the shave off of, so if you couldn't comfortably shave your face with your sharpened iron, it's of no consequence. Every razor a barber ever used off of a much less fine coticule or escher hone, but that traveled to the linen and strop after that is much sharper than you'll get off of any synthetic stone.

If you get better results with the honing guide, then definitely do what makes you happy, especially when it comes to smoother plane irons and block planes, etc. I agree, the job that you do with a guide is more consistent. The job I do with a guide is more consistent, that's the nature of guides. I still use an eclipse on my finest set smoothers that I expect to not sand after and I expect to not see any tool marks from them, the guide makes the geometry more consistent.

At any rate, I thought the same thing you might be thinking when I first started sharpening. My very first edge was made after watching the charlesworth video twice. It was an excellent edge, and I was sure that there must be a secret i didn't know. That wasn't the case. I had the same thought when I started shaving, and I bought a razor that was "professionally honed", only to find out it was significantly less sharp than my daily shaver.

There's no big secret to the fine edge, just experience in getting it fast and every time without having to check it over. If you can shave hair pretty cleanly off of your arm, you're where you need to be, and you can adjust your geometry according to task after that. There's certainly nothing wrong with microbevels and ruler tricks, etc.

[Jim Matthews]

Watch this video (http://www.youtube.com/watch?v=vvTcReENk9g)from Paul Sellers. Listen closely at 1:35 on...

If you're polishing the entire bevel on a chisel or plane blade, you're half way there.
It bears mentioning that you've got to bear down with considerable force to do it this quickly.

For this method to work, you've got to create a significant burr.
This presumes the back of the blade is flat, not "back beveled" as with the ruler trick (which also works).

I find it works best to have the bench height at belt level.
Higher and I can't lean in sufficiently, lower and the angle becomes too steep to cut well.

There are MANY other effective methods.
This is the one the works for me.

[Derek Cohen]

Anyway .. lately I have been sharpening the entire bevel.. Basically polishing it up to 13000 (sigma) and then stropping it.. Afterwards I do a micro bevel with only the 13,000 grit stone and the strop..

Hi Rick

You know you have mastered sharpening when (1) the results are predictable (you no longer need to check the edge - you just know it is sharp), and (2) the method is efficient (that is, you have pared the steps back as far as they can go).

Methods differ but one aspect I must point out - your's is not efficient. There is absolutely no gain in working the whole bevel, and then adding a micro bevel. Wasted effort. Do one or the other only.

Results are predictable when you ensure that the coarsest stone creates a wire edge to the back of the blade, and that subsequent stones polish out all scratches. Front and back. It is not rocket science. It is just a thorough procedure.

Regards from Perth

Derek

[Steve Voigt]

People talk about being able to shave with a chisel or plane blade.. I could do it but would have a few dozen blood soaked toilet paper spots on my face .. :)


As Dave suggests, i wouldn't worry about shaving with a plane blade or chisel--it's a poor way to test for sharpness. For the most part, i just use the blade on whatever I'm making. However, if you want a test, the best one imo, which i got from Peter Galbert's blog, is to cut pine end grain. Lately, i've been keeping a scrap of pine on the bench just for this purpose. I do it because it holds me to a higher standard than what I'm usually working on. If you can cut pine end grain, you can cut almost anything.

[Harold Burrell]

However, if you want a test, the best one imo, which i got from Peter Galbert's blog, is to cut pine end grain. Lately, i've been keeping a scrap of pine on the bench just for this purpose. I do it because it holds me to a higher standard than what I'm usually working on. If you can cut pine end grain, you can cut almost anything.

Yeah, I've heard this too. But just how easily should it cut the end grain??? I mean, I can "cut" end grain with a screw driver.

[Don Dorn]

I too use Paul Sellers method. The reason is that you jettison the jig and don't have to be perfect on the angle as any error at the end of the stroke is what creates the convex bevel. The more I do it, the faster it goes and as Derek said - I don't test anymore, just put it back to work. My stones are on a lower table on the left edge of the bench, but it's dedicated so there is nothing to set up.

The convex bevel didn't really make sense in that it's the back of the blade that does the work so what difference does it make? However, I think it adds strength to the cutting edge as my irons sure seem to stay sharp longer. I can't say that the actual edge is sharper than when I used a jig and a secondary bevel, but this method sure goes faster and is just as sharp.

[Steve Voigt]

Yeah, I've heard this too. But just how easily should it cut the end grain??? I mean, I can "cut" end grain with a screw driver.
The test is, can you pull wide shavings and leave a nice surface. It's a good test, because unlike shaving hair, you see what happens when the blade meets real resistance. If the blade isn't super sharp, it will skip and chatter.
Often, i flunk this test, but i just keep going, because my blade doesn't actually need to be this sharp to do what i need to do. Lately, i've been using the drawknife almost exclusively, and the knife rips through green wh. oak, even though it does a less than great job on the dry pine end grain. So, the test is kind of an aspirational thing; i take note of how well i do, resolve to do better next time, and keep working.

[Jim Koepke]

Yeah, I've heard this too. But just how easily should it cut the end grain??? I mean, I can "cut" end grain with a screw driver.

For me, the end grain of pine test is more about being able to shear off a very thin shaving without pushing over the fibers.

Pine is a soft wood with fiber structure that is very easy to bend and fracture. If a blade is not sharp it is more likely to distort parts of the pine it isn't cutting.

A screwdriver that hasn't been sharpened can break or push end grain, but it will not take a smooth controlled shaving.

jtk

[Dave Parkis]

I also use the Veritas jig for the same reason you do. I'd suggest not honing the entire bevel past 1000 grit. I hone a 25 degree bevel up to 1000 grit and then switch to 30 degrees for the 6000 and 13000 grit stones. This gives me a secondary bevel that's visible and easy to touch up as I go along.

[Adam Cruea]

I don't follow the "does it shave hair" belief either.

Take a sheet of paper and push the blade straight into the edge with no back and forth motion. Does it slice the paper? If so, it's sufficiently sharp. If not, you could probably sharpen more.

My routine is hit my Sigma 1000, 6000, 10000, then take it to an unloaded leather strop. Some of the worst edges I've gotten are actually with a charged strop (which I'm guessing is something I'm doing wrong, but hey).

Also, someone mentioned "considerable pressure". . .I've noticed this only applied to the Sigmas I got from Stu. If I used the same pressure on my Norton's, I would probably shatter them and I doubt they would last.

[Jim Koepke]

I don't follow the "does it shave hair" belief either.

Take a sheet of paper and push the blade straight into the edge with no back and forth motion. Does it slice the paper? If so, it's sufficiently sharp. If not, you could probably sharpen more.

My routine is hit my Sigma 1000, 6000, 10000, then take it to an unloaded leather strop. Some of the worst edges I've gotten are actually with a charged strop (which I'm guessing is something I'm doing wrong, but hey).

Also, someone mentioned "considerable pressure". . .I've noticed this only applied to the Sigmas I got from Stu. If I used the same pressure on my Norton's, I would probably shatter them and I doubt they would last.

Like so many other things; methods of sharpening, degree of bevels, secondary bevels, convex bevels, ways to test the edge all come down to what satisfies the individual needs of the person doing the work.

The ultimate test of a blade's edge is in the work it does for the person using it. In my best tuned smoothers a freshly sharpened blade should be able to cut a shaving of 0.001" or a little less.

The surface left behind by a plane, or chisel, will let you know if there are any nicks in the blade's edge.

A blade does not have to be super sharp to be able to shave some arm hair. In my opinion, there is as much technique involved as there is sharpness. I have thought about shaving my face with a plane blade, but have never tried it. A blade that can remove arm hair may not be able to cut a hanging hair. For me there are different levels of how well a blade shaves arm hair. Same for the hanging hair test. My feeling, having nothing to support it, is a blade at the top of shaving arm hair is at or below the bottom of cutting a hanging hair. Not sure of that.

Cutting paper can be a good test, but one must be aware of the weight of the paper and the humidity levels in the paper. A thin piece of receipt paper in a high humidity situation will be more difficult to cut than a crisp, dry sheet of 20# bond. This will indicate the degree of sharpness one has achieved. It tends to test a very small section of the bevel.

Sometimes before sharpening a blade I test it against a finger nail or even with a finger on the edge. I do not suggest this method. Testing the edge of a blade by feel is something I have done since my first pocket knife over 50 years ago. I haven't cut myself yet doing this. I do tend to have calluses on my finger tips. Many people use a fingernail on a blade's edge to find nicks. Also one can learn over time how sharp an edge is by how it feels against a finger nail. My suggestion is this test method isn't for nail biters.

With oil stones my experience has shown that one has to bear down a bit. With water stones this is likely to cause the edge to dig in and leave a divot on a push stroke.

On water stone my practice is to give the back of a blade a stroke or two mostly to get it moist. This helps me watch the action of the water on the back while the bevel is being honed. Watching the water flow on the back of the blade helps me to keep the bevel flat to the stone. The water movement changes slightly as a burr is developing.

There are a lot of different "tricks" among the methods of sharpening. Amazingly, almost all of them work. It is just a matter of finding the ones that work best for you and your tools.

I am not a big advocate of secondary bevels, but some of my blades have them. Not an advocate of cambering blades, but some of my blades are cambered. Neither am I one to champion the ruler trick, but some of my blades do get a little lift at the top when the back side is being rubbed on a stone. My preference, until it changes, is for a flat bevel. This is mostly because there currently isn't a grinder in my shop. However, at one time one of my blades did have more of a convex bevel, it worked fine.

So my advice to anyone struggling with getting to sharp is to keep it simple and get basic. If one hasn't removed all the nicks from an edge with their coarse stone, they are likely to still be there after the polishing stone. If an edge isn't sharp after working the primary bevel, it may be a lot to ask of a secondary bevel or ruler trick to correct the situation.

jtk

[Jim Matthews]

However, if you want a test, the best one imo, which i got from Peter Galbert's blog, is to cut pine end grain. Lately, i've been keeping a scrap of pine on the bench just for this purpose. I do it because it holds me to a higher standard than what I'm usually working on. If you can cut pine end grain, you can cut almost anything.

+1 This is a consistent test, that has been used by several people attempting to teach me the rudiments of sharpening.
If the pine end grain looks "wet" when the blade passes, you're looking into the open end of the cells.

If it looks dusty, like flour or "furry" the blade isn't polished finely enough to shear the end grain cells - the edge isn't keen and the degree of polish isn't smaller than the cross section of end grain.

It's so simple, and there's not denying the accuracy.
If the blade can manage Pine end grain, the blade's ready.

[Jim Matthews]

Yeah, I've heard this too. But just how easily should it cut the end grain??? I mean, I can "cut" end grain with a screw driver.

When I get a chisel sharp enough, it glides across the surface. If I need to skew, sweep or otherwise manipulate the blade - it might do with more stropping.
I can only plane Pine end grain with my planes skewed. That's an indication to me that the larger blades aren't as finely finished as my chisels.

* sigh *

I once saw Phil Lowe swipe at a piece of end grain so fast I was sure the end would blow out.
No skew, no magical mystery tour - straight across.

That, with a plane I wouldn't have crossed the street to pull out of a trash can.

[Jim Matthews]

So, the test is kind of an aspirational thing; i take note of how well i do, resolve to do better next time, and keep working.

I like that. I fear many are paralyzed by a standard that may be considerably higher than necessity merits.
Not every planing or chisel task requires the finest finish.

My sharpening approach is "Get on with it."

[Jim Matthews]

Some of the worst edges I've gotten are actually with a charged strop (which I'm guessing is something I'm doing wrong, but hey).

Also, someone mentioned "considerable pressure". . .I've noticed this only applied to the Sigmas I got from Stu. If I used the same pressure on my Norton's, I would probably shatter them and I doubt they would last.

I use Diamond stones - there's little risk of digging into the surface and gouging the substrate.
No way I could do the same with a waterstone.

Stropping also requires considerable "downforce" to work effectively.
Two things I'm forever doing wrong - moving too slowly, and changing the angle of attack.

When you strop, a 'wave' of compressed leather forms in front of the bevel as you drag it along.
If you move to slowly, that wave forms a curve that the steel rides against - with differing degrees of resistance.

The idea is to polish the entire surface, at the same time, with the same force - or risk taking off more steel at some point on the bevel.
I'm looking for the bevel to be stout enough to resist deformation, but smooth enough that the shaving slides off it.

If the angle of attack changes (usually because I'm sweeping my hands in an arc, rather than dragging the blade across), the risk is to dub over the sharpened edge.
That induces a steeper bevel at the edge and makes cutting more difficult.

I'm using what was likely a remnant from making a handbag. It's supple, but not compressible.
Remember to put the "rough" side up.
DAMHIKT

[Steve Voigt]

If the pine end grain looks "wet" when the blade passes, you're looking into the open end of the cells.

If it looks dusty, like flour or "furry" the blade isn't polished finely enough to shear the end grain cells - the edge isn't keen and the degree of polish isn't smaller than the cross section of end grain.


OK, that's just really cool. I knew what I was looking for, but didn't really know why. Thanks!

[Charlie Stanford]

Any progress I have made in sharpening has been self taught after reading here. The recent sharpening thread was insightful to me, they always are ..

I use a Veritas jig for chisels and plane blades, my reason for not free hand sharpening is that I cant seem to repeat the same angle over and over ..

Anyway .. lately I have been sharpening the entire bevel.. Basically polishing it up to 13000 (sigma) and then stropping it.. Afterwards I do a micro bevel with only the 13,000 grit stone and the strop..

This is as sharp as i have gotten to date, but I know it could be better..

The micro bevel I create that way is microscopic. I ensure that the back is flat and the sharpening process leaves a burr after each stone.. but for some reason, I cant ever seem to really nail it ..

People talk about being able to shave with a chisel or plane blade.. I could do it but would have a few dozen blood soaked toilet paper spots on my face .. :)

I would love to take a class.. Or sharpen a chisel in front of some old timer, who could say ... " hey ! what was that ! " .. or give pointers..

Would love some videos or similar to watch..

Just get an Eclipse-style honing jig, a piece of glass, and some fine sandpaper from an auto parts store - I think they sell a 2500 grit paper that's way fine enough. Flatten and polish the cutter's flat face. Start with 150 grit and, if the cutter is already pretty flat, move on up pretty quickly (it's fine to make pretty wide skips in grit). Once the back is like a mirror then jig the cutter, work the bevel (no need for micros) until you raise a fine burr on the back. Leave the cutter in the jig and then work the back and bevel several times until there is no trace of the wire edge. You'll be doing this portion of the process all on the finest grit paper. This will only take a minute or two once the back is flattened and polished. Once the back is flat and shiny it should never see anything but the finest grit.

You do not need to do anything after this - do not strop. It's not necessary. There is no rag or anything that needs stropping or polishing after 2500 grit sandpaper. The back and bevel will be like like mirrors, with depth. Stropping and fiddle-farting around after 2500 grit paper has as much chance of undoing the good you've just done as anything.

If you can't work wood with the edges that result from the above procedure then any problems you are experiencing have their genesis elsewhere.

[Jim Matthews]

Just get an Eclipse-style honing jig, a piece of glass, and some fine sandpaper from an auto parts store - I think they sell a 2500 grit paper that's way fine enough.

At roughly $1 per sheet, this method is effective - and expensive.
It's my go-to flattening step, but not for grinding.

I bought some Tri-M-ite new old stock off the auction site that can't be named, at roughly 30 cents per sheet.

It's also difficult to knock off corners on plane irons with regular paper substrates.
Tipping the blade onto the corner tears the paper.
Some of the mylar backed sandpapers are more durable, at greater expense.

I did the math, and a set of diamond stones was cheaper over my remaining lifetime.

It's also a good deal less messy.

[Charlie Stanford]

At roughly $1 per sheet, this method is effective - and expensive.
It's my go-to flattening step, but not for grinding.

I bought some Tri-M-ite new old stock off the auction site that can't be named, at roughly 30 cents per sheet.

It's also difficult to knock off corners on plane irons with regular paper substrates.
Tipping the blade onto the corner tears the paper.
Some of the mylar backed sandpapers are more durable, at greater expense.

I did the math, and a set of diamond stones was cheaper over my remaining lifetime.

It's also a good deal less messy.

It's a way to get the job done without all the hoo-ha about brands, comparison shopping, cost accounting, etc.

I did the math -- quitting woodworking altogether would be cheaper over my remaining lifetime.

[Sam Takeuchi]

I did the math, and a set of diamond stones was cheaper over my remaining lifetime.

It's also a good deal less messy.

But diamond stones don't last life time and its cutting quality deteriorates and depending on what you have and how you use, it could come to end of its usefulness within a couple of years. Of course, It could last for years if you don't use often, but toward the end of its useful life, cutting performance is far from good. For how much they cost and perform over time, I would be hard pressed to say they are good investment if you are calculating cost performance out of those things.

[Jim Matthews]

It's a way to get the job done without all the hoo-ha about brands, comparison shopping, cost accounting, etc.

I did the math -- quitting woodworking altogether would be cheaper over my remaining lifetime.

Okay, I get it. Elemental is better.

Perhaps some pictures (including clean up afterwards), and a stop watch on how you do things would put quantification behind your assertion.

And Charlie? Do try not to be a neckbeard about it.

[Jim Matthews]

But diamond stones don't last life time and its cutting quality deteriorates and depending on what you have and how you use, it could come to end of its usefulness within a couple of years. Of course, It could last for years if you don't use often, but toward the end of its useful life, cutting performance is far from good. For how much they cost and perform over time, I would be hard pressed to say they are good investment if you are calculating cost performance out of those things.

I believe these are legitimate concerns, based on the performance of previous polycrystalline diamond plates.

The Atoma stones use an array of monocrystalline diamonds, which will theoretically outlast my remaining shop time (perhaps another 20 years, if my vision doesn't deteriorate further).
It's important to note that either version of diamond stone available to me are flat. That eliminates one of the tedious aspects of using water stones.

There's also very little slurry generated in the process. That compares favorably to both sandpaper and stone abrasive methods.
(I don't have a sink in my basement shop.)

I don't care to make any suppostions about how long these will last, without any supporting evidence.
What I can say within my realm of experience is that there's less mess, no conceivable way to damage the plates and the edges get genuinely sharp.

All this, and I can take a stock blade (pitted, damaged or nicked blades take longer) from rough to ready in 90 seconds.

Are there ways to get a finer edge? Certainly.
Are there ways to get a sufficiently sharp edge, faster? Perhaps.

Doing both without electricity, a dedicated bench or water source swung the deal for me.

I think it's important to note that this method takes considerable exertion of force, it's not a delicate procedure.
I'm ready for coffee after tuning a new plane blade. More than two blades in a day, and my hands hurt.

Powered methods put the force into the work with a motor.
I'm too much of a hamfist to handle this with a grinding wheel, or belt - I was forever correcting problems of my own making with powered methods.

This way, it's hard to over do things.

[Charlie Stanford]

I believe these are legitimate concerns, based on the performance of previous polycrystalline diamond plates.

The Atoma stones use an array of monocrystalline diamonds, which will theoretically outlast my remaining shop time (perhaps another 20 years, if my vision doesn't deteriorate further).
It's important to note that either version of diamond stone available to me are flat. That eliminates one of the tedious aspects of using water stones.

There's also very little slurry generated in the process. That compares favorably to both sandpaper and stone abrasive methods.
(I don't have a sink in my basement shop.)

I don't care to make any suppostions about how long these will last, without any supporting evidence.
What I can say within my realm of experience is that there's less mess, no conceivable way to damage the plates and the edges get genuinely sharp.

All this, and I can take a stock blade (pitted, damaged or nicked blades take longer) from rough to ready in 90 seconds.

Are there ways to get a finer edge? Certainly.
Are there ways to get a sufficiently sharp edge, faster? Perhaps.

Doing both without electricity, a dedicated bench or water source swung the deal for me.

I think it's important to note that this method takes considerable exertion of force, it's not a delicate procedure.
I'm ready for coffee after tuning a new plane blade. More than two blades in a day, and my hands hurt.

Powered methods put the force into the work with a motor.
I'm too much of a hamfist to handle this with a grinding wheel, or belt - I was forever correcting problems of my own making with powered methods.

This way, it's hard to over do things.

I don't understand two things: 1) your being convinced they'll last the rest of your woodworking lifetime unless, God forbid, you are very old or in very poor health; 2) this bit about "two blades a day" making your hands hurt. Are you talking about honing tools you are using in the course of woodworking? If so, this shouldn't be particularly painful if you let the abrasive do the work it is designed to do.

[David Barnett]

I believe these are legitimate concerns, based on the performance of previous polycrystalline diamond plates.
...
I don't care to make any suppostions about how long these will last, without any supporting evidence.

I'm, too, am satisfied with diamond for sharpening woodworking tools by hand* where my mainstay has long been a well-broken-in 30µ plate followed by 1µ compound on cast iron.

Misconception and misinformation is demonstrably rife regarding monocrystalline versus polycrystalline diamond, both fixed (electrobond) and otherwise (loose, compound), extending to use and longevity of diamond plates, whether mono, poly or hybrid, for sharpening.

Consider the following abstract from Nature 421, 599-600 (6 February 2003)

Materials: Ultrahard polycrystalline diamond from graphite

Polycrystalline diamonds are harder and tougher than single-crystal diamonds and are therefore valuable for cutting and polishing other hard materials, but naturally occurring polycrystalline diamond is unusual and its production is slow. Here we describe the rapid synthesis of pure sintered polycrystalline diamond by direct conversion of graphite under static high pressure and temperature. Surprisingly, this synthesized diamond is ultrahard and so could be useful in the manufacture of scientific and industrial tools.

Also informative is this promotional article (http://www.metallographic.com/Newsletters/PC-diamond-newsletter3.PDF) for Pace Technologies, a manufacturer of polycrystalline diamond products for metallographic research and industry, worth reading, in my opinion, as it helps to dispel confusion on the subject.

I have Eze-Lap polycrystalline plates approaching twenty years of considerable use—the Eze-Lap 600 was in my everyday sharpening regimen during my more-active years—and even rotary gem faceting laps that still have enough life for prepolishing after nearly as long.

*For establishing bevels—hollow, flat, convex—I use bench & belt grinders or rotary laps.

[David Barnett]

But diamond stones don't last life time and its cutting quality deteriorates and depending on what you have and how you use, it could come to end of its usefulness within a couple of years. Of course, It could last for years if you don't use often, but toward the end of its useful life, cutting performance is far from good. For how much they cost and perform over time, I would be hard pressed to say they are good investment if you are calculating cost performance out of those things.

Sam, as a friend used to admonish his errant charges on grand rounds, "I cannot appreciate that diagnosis."

My experience contradicts your conclusions as to longevity of well-made and properly used electrobond diamond plates inasmuch as I have an Eze-Lap approaching twenty years in my everyday sharpening regimen, a lap I now consider properly broken-in. The convergence of cutting action, scratch pattern and "feel" this stone has finally reached makes it a consummate joy to use.

Conservatively amortized over its life to date, its cost is easily less than one penny per day, and there is no reason, properly used, such a plate should not last the rest of my life and then some.

From Jeff Greef's Sharpening Tools:

DMT Duo-Sharp Diamond Stones

Diamond stones are more expensive, but diamond is the hardest of all abrasive materials, so these stones will last forever. As well, diamond is known to cut metal fast. Precision flatness, durable construction.

So while "forever" may be a stretch, discounting diamond as cutting poorly when it loses its initial aggressiveness after proper break-in, is commensurately unrealistic.

[Bob McDermid]

We have tried oil, water, diamond, synthetic/natural, all manner of stones. The sand paper sharpening method is the easiest and quickest for people with absolutely no experience to achieve very conistantly sharp tools. We teach approximately 300 apprentices to sharpen every year. Is it the best method? I think the best method is what ever works for you. If the tool is meant to cut wood that is how you should test it. Just my observations and opinion. regards Bob

[David Barnett]

I think the best method is what ever works for you. If the tool is meant to cut wood that is how you should test it. Just my observations and opinion. regards Bob

Well said, Bob—each should determine what is best for oneself. I shoot for my preferred balance of fast, easy, cheap so have found my idiosyncratic best for sharpening woodworking tools.

Can I produce edges finer than my everyday regimen? Of course. Once one knows what sharp is, what sharp enough is and how to get it, one can choose from what's available and preferred.

Abrasive papers and films are hard to beat for beginners and I use them, too, although less for edge refinement than other purposes these days.

[Sam Takeuchi]

Sam, as a friend used to admonish his errant charges on grand rounds, "I cannot appreciate that diagnosis."

My experience contradicts your conclusions as to longevity of well-made and properly used electrobond diamond plates inasmuch as I have an Eze-Lap approaching twenty years in my everyday sharpening regimen, a lap I now consider properly broken-in. The convergence of cutting action, scratch pattern and "feel" this stone has finally reached makes it a consummate joy to use.

Conservatively amortized over its life to date, its cost is easily less than one penny per day, and there is no reason, properly used, such a plate should not last the rest of my life and then some.

From Jeff Greef's Sharpening Tools:

DMT Duo-Sharp Diamond Stones

Diamond stones are more expensive, but diamond is the hardest of all abrasive materials, so these stones will last forever. As well, diamond is known to cut metal fast. Precision flatness, durable construction.

So while "forever" may be a stretch, discounting diamond as cutting poorly when it loses its initial aggressiveness after proper break-in, is commensurately unrealistic.

In my earlier days, I've used 3 DMT Dia-Sharp plates (only for sharpening, not for lapping stones), and they've come to be very frustratingly slow to cut and for all practical purposes, they were not at all good performers in about 2 years. I don't have books or quotes to cite, but I have 3 utterly useless piece of steel plates that didn't last and dont' cut. Also another diamond plate I've used for waterstone lapping, that a cheap, but extremely flat one was worn out in about 2.5 years of regular use, but for the price and its flatness, I think it was a good buy. And after having 3 DMT Dia-Sharp plates that are not flat, far from "precision flatness" that you can feel the blade riding over valleys and uneven surface, sometimes enough to make blade skid, because space between the diamond plate and bevel traps water and hydroplane the blade for a moment, a quote or book from someone else don't convince me at all. I'm not saying they are lying or casting suspicion on their claims, but their experiences don't match mine. I know that it's not just you who has very good diamond stone that's been hard at work for decades, I vaguely remember George Wilson mentioning having a very old diamond stone that was (is?) well performing for decades, but then I also know many who had had used diamond stones and ended up in disappointment over its so called performance and precision before long.

I didn't say anything about initial aggressiveness. In fact, I wouldn't count initial aggressiveness as indicative of diamond stone's cutting performance overall either. It scratches too deeply. Anyone who has had experiences with diamond stone probably know its initial cutting performance only last for a short time, so I don't know why you thought I was talking about its initial aggressiveness.

I know that the longevity of using diamond stone is not to put so much pressure and also spread wear (like any other stones really), but when someone is putting so much force that his hand hurts after sharpening two, and doing full bevel (he mentioned that he use Paul Seller's method), and if that doesn't cause premature wear on diamond plate, nothing will. I'm not knit picking his method of sharpening, but I have my doubts as to how long diamond stones will last, especially because hypothesis is that it should last remaining of his woodworking life, how long that may be.

To be fair, I can see diamond stones lasting for a long time when combined with grinder or otherwise powered method of establishing bevel and/or doing major work and in that case, plates not being flat doesn't affect as much if the plates don't touch the full bevel.

[Zach Dillinger]

I like that. I fear many are paralyzed by a standard that may be considerably higher than necessity merits.
Not every planing or chisel task requires the finest finish.

My sharpening approach is "Get on with it."

+1 to this.

[Hilton Ralphs]

In my earlier days, I've used 3 DMT Dia-Sharp plates <snip> And after having 3 DMT Dia-Sharp plates that are not flat, far from "precision flatness" that you can feel the blade riding over valleys and uneven surface

David Barnett was referring to Duo-Sharp stones, not the plates you have. Different animal altogether.

[Sam Takeuchi]

I know Duo-Sharp and Dia-Sharp are different things, but if you read throughout the thread, nothing was said about Duo Sharp, until D. Burnet posted


"Sam, as a friend used to admonish his errant charges on grand rounds, "I cannot appreciate that diagnosis."

My experience contradicts your conclusions...

What I understood was that he posted that quote as an example of the characteristics of diamond stone. Was I supposed to assume that's what he was going to post that when I wrote "diamond stones don't last forever and can be work in a couple of years depending on use" before his post? In the same manner, I can say I was talking about Dia-Sharp and thus characteristics of Duo-Sharp has no relevance in this discussion? The discussion was about diamond plate, without being product specific. Because he cited someone's observation about Duo-Sharp, does that encapsulate qualities of diamond stone across the board? No, it doesn't. So I don't see why it is relevant that the quote cited mentions Duo-Sharp.

[David Barnett]

In my earlier days, I've used 3 DMT Dia-Sharp plates (only for sharpening, not for lapping stones), and they've come to be very frustratingly slow to cut and for all practical purposes, they were not at all good performers in about 2 years.

Quite frankly, most every disappointment I've heard about or personally experienced with diamond plated sharpening stones concerned DMT so I thoroughly understand what you're saying. I have one each red, blue and green disappointments to remind me of just how far an otherwise viable and worthwhile technology can stray from adequacy in flatness, quality of cut and longevity. Put simply, I hereafter eschewed all DMT products.

For sharpening woodworking tools, monocrystalline diamond plates have rarely failed to disappoint as to longevity and quality of cut, whereas polycrystalline diamond has rarely failed to please—one reason why I've long favored Eze-Lap which still is made with polycrystalline diamond, although monocrystalline has been added to the mix. Rather than monocrystalline's rapid deterioration of desired cutting characteristics, polycrystalline stones actually improve with use until finally settling into reasonably fast-cutting hones with wonderfully smooth, consistent scratch patterns.

Monocrystalline diamond is wholly appropriate for certain uses, of course, and can rapidly produce highly uniform surfaces in very hard materials, especially when aligned and distributed as found in the excellent 3M films. I use mostly monocrystalline diamond for all gem faceting and polishing on rotary laps but still prefer polycrystalline for some gems and nearly all work on metals, whether sharpening or polishing.*

An interesting comparison (http://www.metallographic.com/Newsletters/PC-diamond-newsletter3.PDF) is explained in product literature from Pace Technologies, which I linked to in my earlier reply to Jim Matthews.

Flatness, however, is a manufacturing issue and I'm very particular in this regard. DMT does not satisfy my needs in this respect.


Also another diamond plate I've used for waterstone lapping, that a cheap, but extremely flat one was worn out in about 2.5 years of regular use, but for the price and its flatness, I think it was a good buy.

Having only briefly used diamond plates for flattening water stones, I've not experienced that degree of attrition. It didn't take so terribly long, though, to puzzle why I was still using waterstones when the diamond stones used to flatten them better met my needs—headslap!


And after having 3 DMT Dia-Sharp plates that are not flat, far from "precision flatness" ... I'm not saying they are lying or casting suspicion on their claims, but their experiences don't match mine.

Nor mine. Here again, regarding DMT, we are in total agreement.


I didn't say anything about initial aggressiveness. In fact, I wouldn't count initial aggressiveness as indicative of diamond stone's cutting performance overall either. It scratches too deeply.

While this speaks in part to the initial cutting characteristics of both crystal habits, the sharper, deeper, angular troughs left by monocrystalline stones take more work at finer grits to mitigate, whereas polycrystalline diamond, due to its initial shape and varied presentation angles, actually gets you closer to the next stone and final polishing more quickly and with less metal to remove at each step.


I know that the longevity of using diamond stone is not to put so much pressure and also spread wear (like any other stones really) ... Anyone who has had experiences with diamond stone probably know its initial cutting performance only last for a short time, so I don't know why you thought I was talking about its initial aggressiveness.


I think that last sentence could largely be attributed to having first experienced a DMT or other monocrystalline diamond hone without the opportunity to compare it to polycrystalline.

Initial cutting is linked to loss of cutting efficacy and this bears on the distinction of monocrystalline versus polycrystalline sharpening and product evaluation. The initial cut on a polycrystalline hone is initially less aggressive than most monocrystallines, and that initial aggressivenes prevails throughout a much longer break-in curve than monocrystalline stones, so would disabuse you of the notion that your experiences are unvarying or should be regarded as rule-of-thumb for all diamond stones.

It would almost appear that we're discussing two entirely different sharpening technologies, much as the two blind men drawing conclusions about how an elephant looks from examining wholly different parts.

In my opinion, it really is as simple as the difference between mono and polycrystalline diamond. Yes, there are other issues—bonding, substrates, flatness and so on—but the two different diamond crystal habits and products do manifest their differences in two polar sharpening experiences.


To be fair, I can see diamond stones lasting for a long time when combined with grinder or otherwise powered method of establishing bevel and/or doing major work and in that case, plates not being flat doesn't affect as much if the plates don't touch the full bevel.

Yes, I should clarify that I do not use diamond electrobond plates for establishing bevels and do not recommend them for that. Whether for flat, hollow or occasionally convex bevels I use powered bench and belt grinders or rotary laps for all but my narrowest chisels and certain carving tools. Also, given the speed at which I perform the hand honing parts of my regimen, diamond stones are only used for a very few strokes before proceeding to the polishing lap, so yes, this amortizes stone wear differently than one who establishes bevels and flattens tool backs.

*An interesting wrinkle that addresses some advantages once offered only by polycrystalline diamond, is the newer friable monocrystalline diamond (http://www.palagems.com/pgt_diamond.htm) which gives a fast and aggressive but uniform cut, breaking down evenly to a finer cut during use.

I, however, still prefer the rounder troughs left by well broken-in polycrystalline diamond for electrobond diamond honing laps.