Microbevel or not

[Joe Cowan]

I was just wondering how many put a microbevel on their plane irons/chisels, or just finish the primary bevel to the sharpness level needed.

[Jessica Pierce-LaRose]

I tend to hollow grind the majority of my tools on a 6" grinder, so I don't bother much with a microbevel anymore. Before I started using that, I tended to microbevel on harder steels or thicker blades, just to make the job a little quicker.

I still do it from time to time, particularly if I'm trying to squeeze out a couple more sharpenings before returning to the grinder. Since I tend to freehand hone, I generally only microbevel on my higher grit stones - makes that part of the sharpening go a little easier, but since my 1K still chews through material faster, I avoid getting an increasingly steeper microbevel each time I sharpen by returning to the original bevel each time I hit the coarse stone.

[John Coloccia]

I don't bother with micro bevels or hollow grinds anymore. I just strop a lot. In fact, I sold off much of my sharpening gear. I simply got tired of all the rituals.

[David Weaver]

I was just wondering how many put a microbevel on their plane irons/chisels, or just finish the primary bevel to the sharpness level needed.

I do it on smoothing planes. Usually. I do something similar freehand to chase the burr on the coarse plane irons. But I don't do it on chisels.

[Chris Griggs]

I typically free hand hone right on the hollow grind. Sometimes I will lift up and micro bevel a bit on my higher grit stones, or if I am refreshing an edge on a strop I will often lift a tad higher then the hollow grind. The other situation where I sometimes micro bevel is if my hollow as been mainly honed out and I don't feel like regrinding at the moment. In those case I will sometimes freehand hone a micro bevel starting at my 1k stone - I can get a few extra rehonings out of an edge that way before going to the grinder. Of course, after a few rehonings on the MB it grows or rounds over and then its back to the grinder and honing in the primary hollow grind.

[Jessica Pierce-LaRose]

I don't bother with micro bevels or hollow grinds anymore. I just strop a lot. In fact, I sold off much of my sharpening gear. I simply got tired of all the rituals.

Good point there - I still hollow grind because 5 minutes at the grinder makes free-hand honing a little quicker and much more fool-proof when I'm not paying as much attention as I should, but with my chisels, the more I strop, the less I have to hone, although I do tend to get to a point where stropping has diminishing returns, (but that may be my stropping set up or technique) and it's back to the stones. I think stropping was one of the most eye opening things in sharpening for me.

Out of curiosity, what's your stropping set-up, John?

[Michael Fross]

I use a grinder to create the primary bevel (normally 25 degrees). I freehand sharpen by lifting up slightly to create a secondary bevel on my first stone (1000) and then lift slightly more on my last stone (16k). You end up removing very little material so its fast. For example, on the 16k stone, it only takes about 10 seconds.

I've tried lots of techniques, but for me this is the fastest. Takes about a min to resharpen unless I have to hit the grinder again.

I love hearing all the great techniques. There is certainly more than one way to skin this cat.:-)

Michael

[John Coloccia]

Good point there - I still hollow grind because 5 minutes at the grinder makes free-hand honing a little quicker and much more fool-proof when I'm not paying as much attention as I should, but with my chisels, the more I strop, the less I have to hone, although I do tend to get to a point where stropping has diminishing returns, (but that may be my stropping set up or technique) and it's back to the stones. I think stropping was one of the most eye opening things in sharpening for me.

Out of curiosity, what's your stropping set-up, John?

A piece of leather scrap from Tandy glued to a piece of MDF. I think I have about $.50 invested. LOL. I keep that charged with Simichrome and I don't worry about cutting into it too much. I'm on my second or third one. When it gets beat up, I toss it out and build a new one for $.55 (have to account for inflation). I also have a nice Butz strop that I paid some coin for and I do try to keep that one nice. I keep one side charged with Simichrome, and the other side dry.

Then I have a couple of Spyderco ceramic stones for when stropping stops working. A few swipes freehand on that and I'm back in business. When all that stops working, I touch it for a second on the Worksharp, and I'm back in business.

My Butz
248034

I guess I lied about the other one. It's a piece of Mahogany. Probably quartersawn Honduran. If you use rift saw, or African mahogany (Khaya), it will ruin all of your tools. Be sure to use the right shade of leather. To light and it will leave scratches. Too dark and your edge will be fragile. Ask where the cow came from. Cows from the US are the best, but lately all I've been able to find is cows from Brazil and the leather isn't fully tanned all the way through. What is this world coming to? :p
248033

[Derek Cohen]

Uh guys ...

... a micro bevel is a tiny bevel. It has nothing to do with angles.

... a secondary bevel is a bevel that is honed at a higher angle than the primar bevel. It is all about angles, not size.

When you hone a primary bevel directly on a hollow ground, you create a micro bevel that is coplanar with the primary bevel.

When you hone a secondary bevel on a flat or a hollow ground primary bevel, you create a micro secondary bevel.

Another common alternative is to hone on a flat primary bevel, maintaining a coplanar bevel, such as with Japanese blades.

And a last possibility is to grind/hone a convex bevel, ala the style Paul Peller promotes. This is effectively a secondary microbevel.

Clear as mud :)

Regards from Perth

Derek

[John Coloccia]

Uh guys ...

... a micro bevel is a tiny bevel. It has nothing to do with angles.

... a secondary bevel is a bevel that is honed at a higher angle than the primar bevel. It is all about angles, not size.

When you hone a primary bevel directly on a hollow ground, you create a micro bevel that is coplanar with the primary bevel.



Well, if you want to get technical about it, honing a hollow ground gives you a bevel that is coplanar with the plane that closes the cylindrical surface you ground into the blade...you can't be coplaner with the bevel because it's a cylindrical surface and the points don't lie on a plane :p

[Chris Fournier]

I dry grind on a 7" bench grinder for a hollow grind. Then I hit the stones. I will ususally put a micro bevel on everything as I find that it speeds up re-sharpening. What is a micro bevel? 2 pulls at a 2ish degree increased angle to the final 8000 grit water stone. Sharpening is not a chore to me and it all happens very quickly as I have a workable process and I've stuck to it for years.

[Derek Cohen]

Well, if you want to get technical about it, honing a hollow ground gives you a bevel that is coplanar with the plane that closes the cylindrical surface you ground into the blade...you can't be coplaner with the bevel because it's a cylindrical surface and the points don't lie on a plane :p

John, I find what has been written so far in this thread very confusing as posters appear to mix up secondary bevels with microbevels. Perhaps a few definitions might unravel what they are meaning to write?

The thing is, you automatically add a microbevel when honing on a fresh hollow grind. Whether this is coplanar or secondary is unclear in any of this posts.

Regards from Perth

Derek

[Adam Cherubini]

Hi Joe-

I think it's a mistake to seek a consensus on issues like this one. My take is that for thick tools, honing an entire bevel is a waste of time and effort. Guys who do it seem to do it for reasons of expedience for their sharpening technique. The chisel doesn't need a fully polished bevel to cut (but read below carefully).

I'll defer to Derek on the naming. What I do is grind low- like 20 degrees, then hone a small area at the cutting edge to the angle I prefer.

Only thing I can add is that the area behind the edge is somewhat important. For those of you who hollow grind, the chisel thinks that rough ground area IS the bevel. From the chisel's point of view, you hollow grinders are creating secondary bevels (using Derek's terminology). And the hard line that foams between the bevel at the edge and the hollow is a terrible stress concentration. I know some of us hone the hollow completely away- which is fine.

I suspect one of the major failure modes of edges involves bending. Supporting the edge behind the honed tip is important. Reducing stress concentrations behind the edge can help the tool react the stress we apply. I think the best shape scientifically is a smoothly polished elliptical (convex) bevel. That aside, here's my Given that, here's my advice:

1) if you choose to grind low and hone high (as I do), polish the ground area smooth at least. Just so happens, I think Leonard Lee arrived at this conclusion many many years ago. This was the apparent theory behind the veritias honing jig.
2) Avoid "side honing". Side honing creates scratches precisely where you don't want them....like perforations on a paper towel roll. If you really prefer side honing, polish your bevel to a high hone for maximum strength.
3) Reducing the bevel angle of a chisel used for chopping both weakens the edge but also reduces bending stress (making the edge last longer). For each chisel, there is a "sweet spot". My belief is that widths of chisels (and the radius of a cambered plane iron) affects the tool's strength. Therefore, each tool in my shop has a slightly different angle. My wide chisels typically have lower bevel angles than the narrow ones. Coincidentally, the planes with the greatest curvature to their blades are the roughing planes and have the higher angles. BUT- planes with higher pitches need higher bevel angles because the bending stress is that much greater.

Conclusion:
You inevitably must decide how to sharpen based on your skill, equipment, and projects. I think the science I wrote about above is helpful, but I think it's up to you to fit it into your sharpening regime, and not vice versa. The single biggest thing I learned about sharpening in last 5 years I learned from my friend Warren Mickley- sharpening should be quick and easy- so easy that you can do it every 20 minutes if need be without much interruption. I used to look at it as something I did between projects. Now it's integral with my bench work. I think Warren can touch up an edge at his bench in under a minute.

[John Coloccia]

John, I find what has been written so far in this thread very confusing as posters appear to mix up secondary bevels with microbevels. Perhaps a few definitions might unravel what they are meaning to write?

The thing is, you automatically add a microbevel when honing on a fresh hollow grind. Whether this is coplanar or secondary is unclear in any of this posts.

Regards from Perth

Derek

People normally use "microbevel" to mean a small secondary bevel. The two terms are normally used interchangeably. The only time it really needs a distinction is when you're talking about mortise chisels, because they may have a very shallow primary bevel, and a very steep secondary bevel....which is not "micro" by any means. It's usually a significant, stout secondary to keep the edge from falling apart.

I don't think most people would consider honing a hollow grind as a microbevel. Usually, that term is reserved for a small, secondary bevel, even though you're right that honing a hollow does indeed form a small bevel that would otherwise not be there.

[Jessica Pierce-LaRose]

[QUOTE=John Coloccia;2020545

I guess I lied about the other one. It's a piece of Mahogany. Probably quartersawn Honduran. If you use rift saw, or African mahogany (Khaya), it will ruin all of your tools. Be sure to use the right shade of leather. To light and it will leave scratches. Too dark and your edge will be fragile. Ask where the cow came from. Cows from the US are the best, but lately all I've been able to find is cows from Brazil and the leather isn't fully tanned all the way through. What is this world coming to? :p
[/QUOTE]

Wait, I'm dumb - are you being funny or serious here? I guess I can see poor quality leather being a problem (but if it's not tanned, doesn't it rot eventually?) But how does the wood behind the leather matter other than being a stable substrate?

[John Coloccia]

Wait, I'm dumb - are you being funny or serious here? I guess I can see poor quality leather being a problem (but if it's not tanned, doesn't it rot eventually?) But how does the wood behind the leather matter other than being a stable substrate?

Ha ha...of course I'm kidding a little. :) It's a piece of scrap leather glued to something somewhat flat. I guess in the instrument building world, there's so much myth, lore and worrying about minutia that you just have to poke fun at it sometimes :D

[David Weaver]

Other than derek's page articles, I can't recall someone else using the term microbevel for the honed surfaces on a hollow grind.

We could poll it, but I think almost universally, people think of a secondary bevel when the term microbevel is used.

[David Weaver]

Hi Joe-

I think it's a mistake to seek a consensus on issues like this one. My take is that for thick tools, honing an entire bevel is a waste of time and effort. Guys who do it seem to do it for reasons of expedience for their sharpening technique. The chisel doesn't need a fully polished bevel to cut (but read below carefully).

I'll defer to Derek on the naming. What I do is grind low- like 20 degrees, then hone a small area at the cutting edge to the angle I prefer.

Only thing I can add is that the area behind the edge is somewhat important. For those of you who hollow grind, the chisel thinks that rough ground area IS the bevel. From the chisel's point of view, you hollow grinders are creating secondary bevels (using Derek's terminology). And the hard line that foams between the bevel at the edge and the hollow is a terrible stress concentration. I know some of us hone the hollow completely away- which is fine.


I've seen various people talk about the weakness of the hollow grind, but if you are using a 20 degree primary bevel and then creating a secondary, and someone else is grinding a hollow at 25 degrees, no part of their edge will be less steep than a 20 degree primary bevel and the hollow ground edge will be the stronger of the two. There is no reason for the stresses to be any different at the break into the hollow than they would be at the back of a secondary bevel on a shallow primary.

This comes up on here, and someone has followed odate's book too closely about the hollow grind, or whoever else has talked about it without ever actually seeing a failure. Or maybe it's discussion about japanese chisels and very steep hollows. Whatever it is, I've never seen edge failures caused by a hollow grind when the hollow is just as steep as a common primary. Actually, I've never seen them at all. Edge failures on good chisels are usually small chipping, and on planes, the same type of chipout if the total angle is too shallow at the edge.

I think the optimal profile is without regard to the shape of the edge, it's with regard to the final angle for practicality. If A2 steel is less than 31 or 32 degrees, it often has chipout problems. It doesn't matter if the edge is convex, hollow ground or flat ground. The fact that it is difficult to be that precise freehanding a convex bevel suggests that if someone is changing their angle until they get good edge durability, they'll shoot past that and instead have an edge that is almost the exact shame shape as a worn bevel that is made of intersecting planes.

But in the end, it doesn't matter a lot. Anyone with hands and eyes to judge can figure out what works best under any given method. The condemnation of the hollow grind for anything other than super small radius (smaller than any of us would use) is not accurate, though, certainly not in practice.

[Chris Griggs]

What about this idea that side sharpening creates a weak edge, like a perforation in a paper towel? I had read that "in theory" a bevel honed side to side would be keener and stronger. In practice I'm not sure it makes any difference - what is easier for someone to hone consistently is, in my opinion, what works best in practice. I tend to be more consistent with the edge turned sideways or almost sideways anyway.

Could someone please elaborate or share further thoughts on this?

[Andrae Covington]

I was just wondering how many put a microbevel on their plane irons/chisels, or just finish the primary bevel to the sharpness level needed.

I used to microbevel nearly everything that wasn't nailed down. I am one of those lightweights who uses a honing jig, in my case the Veritas Mk.II, which makes it very easy to increase the angle a little for secondary and even tertiary bevels. Eventually they would get too big to even generously be considered "micro", and then I would have to re-establish the primary bevel. Without a grinder, I had to do this on my DMT stones, which meant grinding the entire flat bevel. I found that the steeper angles of the secondary (and sometimes tertiary micro) bevels required me to remove more and more metal to recreate a clean flat bevel at the primary angle. So I've mostly given up on steeper additional bevels (micro or otherwise).

I know that people are going to tell me that I'm not reducing the amount of work involved. So let me geek out here and run some numbers. Consider a blade which is 2" wide and 1/8" thick, with a single bevel at 25°. If I have to remove 0.001" (1 thou) to clean up the bevel, that is a volume of 0.00025 cubic inch. If that blade has a 27° secondary bevel which is 0.01563" (1/64"), then to take the entire bevel down to 25° requires removing 0.00092 cubic inch. That is over three times the material. If that secondary bevel has grown to 0.0625" (1/16"), that requires removing 0.00238 cubic inch, which is over nine times the material.

If I only use one bevel angle, and keep up with sharpening regularly, then I don't have to remove as much material each time, and I can get back to work. Out of laziness, some of my blades have a single bevel at the steeper 27°, because I don't feel like grinding them back to 25°. I just extended the secondary bevel until it became the only bevel.

My chisels are narrow enough to work on the hand-cranked grinder I eventually picked up. For some of those, I have rough ground down to ~20° and then honed what is really the secondary bevel at 25°. I'm not hollow grinding in the traditional sense, leaving flats at the front and back of the bevel to register on the stones. I'm just excavating the back arris of the bevel so I don't have to grind it away on my stones.

[Jim Koepke]

What about this idea that side sharpening creates a weak edge, like a perforation in a paper towel? I had read that "in theory" a bevel honed side to side would be keener and stronger. In practice I'm not sure it makes any difference - what is easier for someone to hone consistently is, in my opinion, what works best in practice. I tend to be more consistent with the edge turned sideways or almost sideways anyway.

Could someone please elaborate or share further thoughts on this?

It may be the scratches from side to side sharpening (parallel to the edge) are more susceptible to compression stresses than scratches from sharpening perpendicular to the edge. In most cases, this may not rear its ugly head unless one is working with extremely acute bevel angles or very deep scratches.



Hi Joe-

I think it's a mistake to seek a consensus on issues like this one.

My thought is the best consensus for a subject like this is that most of us can agree that whatever works best for anyone is what is best for them.




The single biggest thing I learned about sharpening in last 5 years I learned from my friend Warren Mickley- sharpening should be quick and easy- so easy that you can do it every 20 minutes if need be without much interruption. I used to look at it as something I did between projects. Now it's integral with my bench work. I think Warren can touch up an edge at his bench in under a minute.

Between work in the shop and SWMBO's "Honey Do List" there isn't time for me "between projects."

Stropping at the bench helps to save an edge between trips to the stones. Usually my blades are honed before getting dull enough to require major work on the stones.

Since there currently isn't a grinding wheel in my shop, my blades do not get hollow ground. One of these days a round tuit will come my way and a stand will be built for the large wheel my brother gave me.

The only blade of mine that gets a secondary bevel is a thick plane iron. It is difficult to hone the entire bevel since it sticks to the stone due to the large surface area of the bevel.

Occasionally a make shift blade holder is used. Most of the time my honing is done free hand.

jtk

[Adam Cherubini]

There is no reason for the stresses to be any different at the break into the hollow than they would be at the back of a secondary bevel on a shallow primary.
I'm not sure I disagree with what you're saying overall. And I agree that the science may contribute very little. But just for sake of discussion, that break we're talking about should be smooth. And that's the natural effect of certain styles of hand honing. Good to think of mortise chisels when we consider this topic.



This comes up on here, and someone has followed odate's book too closely about the hollow grind, or whoever else has talked about it without ever actually seeing a failure.

Are you sure that's true, David? Leave the invectives out. You are making good points without them.



I've never seen edge failures caused by a hollow grind when the hollow is just as steep as a common primary. Actually, I've never seen them at all. Edge failures on good chisels are usually small chipping, and on planes, the same type of chipout if the total angle is too shallow at the edge.

With respect, if you find your tools are chipping, you may be waiting too long to inspect or hone. My tools' edges all start to roll over long before chips occur. The rolling is the evidence of bending being the failure mode as opposed to compression since the edges tend to roll always to one side (tho the side does seem to vary based on usage). And analytically, chisels see great amounts of bending. Of course plane irons do.


The condemnation of the hollow grind for anything other than super small radius (smaller than any of us would use) is not accurate...

Ok if you don't agree or think in your experience it doesn't matter.. happy with that. But scientifically the hollow grind does matter. There are several technical issues- the shape, the discontinuity in tangency and or curvature, and the surface finish of the facets.

BTW, I never read Odate's book. But I do think it's curious to say the least that guys with great amounts of practical experience (I'm not including myself in this) all basically arrive at the same conclusion.

[Adam Cherubini]

What about this idea that side sharpening creates a weak edge, like a perforation in a paper towel?

When a chisel is malleted, pressure builds up on the beveled side due to the wedge effect. That force is often reacted not by wood, but by our hands holding the chisel. That means one side of the tool goes into tension and the other side goes into compression.

Now you can't take this too far but...
Imagine stress like running water in a stream. The scratch is like a large stone on the shore. The stone interrupts the flow and causes the water to have to travel faster to get around the stone and keep up with the water in the center of the stream. That increased speed is increased stress. Get too much at the end of that scratch and the scratch can become a crack.

In any case, scratches reduce the strength of a material to transmit load. When testing the strength of metal, we polish them to a mirror polish to get the best possible results. "Notched" or scratched specimens are subsequently made to test more real world conditions. The result is always much reduced capability.

There's something else at work here that I don't know much about. It's called edge "morphology". As I understand it, the act of honing front to back can encourage metal crystals to align themselves parallel to the scratches, creating a stronger edge. Maybe somebody else can help me with this one.

Again, I think you'll find that guys all over the world have been honing essentially the same way for 500 years. We question everything which is good sometimes and bad other times.

[David Weaver]

Are you sure that's true, David? Leave the invectives out. You are making good points without them.


That's no invective, it's something that's cited as a reason not to hollow grind (Odate's book) - not by you, and my response wasn't intended to read "adam says _____ from odate's book"


With respect, if you find your tools are chipping, you may be waiting too long to inspect or hone. My tools' edges all start to roll over long before chips occur. The rolling is the evidence of bending being the failure mode as opposed to compression since the edges tend to roll always to one side (tho the side does seem to vary based on usage). And analytically, chisels see great amounts of bending. Of course plane irons do.


None of my tools are chipping. The rolling indicates that your chisels are soft enough that they fail by rolling instead of chipping.



Ok if you don't agree or think in your experience it doesn't matter.. happy with that. But scientifically the hollow grind does matter. There are several technical issues- the shape, the discontinuity in tangency and or curvature, and the surface finish of the facets.

If there is no practical or material difference in edge durability at a given final bevel angle, then it doesn't matter. There is no legitimate argument that a hollow grind weakens a similar grind in woodworking tools. Long ago, I asked folks to speak up about the hollow bevel angle they had that had greater failure rates, or cracks at or up to the hollow when a flat bevel at the same grinding angle didn't have similar failures and nobody has ever identified any. Overanalyzing a conclusion won't make it different.

[Jack Curtis]

Microbevels? No. Secondary bevels? No. Hollow grind? No.

As to hollow grinding, I use a Makita horizontal grinder which doesn't produce hollows. And the normal vertical wheel grinder is not wide enough to grind most plane blades in one go, you have to move the blade back and forth, which makes it more difficult to make a hollow that goes straight across the blade. Granted, it's easy with most chisels, but from a purely visual standpoint, they seem weaker than a flat bevel to me.

I read Odate as confirmation. The rest is original logic. Overanalysis? I don't think so, but it's of no importance.

[Chris Fournier]

Other than derek's page articles, I can't recall someone else using the term microbevel for the honed surfaces on a hollow grind.

We could poll it, but I think almost universally, people think of a secondary bevel when the term microbevel is used.

A micro bevel is certainly a secondary bevel which naturally has it's own distinct geometry relative to the back of the balde and the primary bevel. A micro bevel is just that though -micro.

[Zach Dillinger]

Microbevel or not?

Not.

[Michael Ray Smith]

I used to add a small, secondary bevel to both plane irons and chisels, but I've pretty much stopped because I don't see a significant benefit. The only exception is when I'm sharpening something to sell. Then I add a secondary bevel just because there's so much stuff out there than says you're supposed to do it, I don't want the buyer to complain about the absence of one.

[Michael Ray Smith]

Oh, one other context. . . . I generally put a convex bevel on draw knives. A lot of them are factory ground that way. I sharpen them freehand, and I just got used to doing them like that. I also put a very slight crown on the back, mainly because the backs of old draw knives are seldom flat and they often have a lot of pitting, so it's less work to put a crown on them. I also like using them better if they have a bit of a crown.

[Tim Put]

... the hard line that foams between the bevel at the edge and the hollow is a terrible stress concentration. I know some of us hone the hollow completely away- which is fine.

I suspect one of the major failure modes of edges involves bending. Supporting the edge behind the honed tip is important. Reducing stress concentrations behind the edge can help the tool react the stress we apply. I think the best shape scientifically is a smoothly polished elliptical (convex) bevel....

The (relative) outcropping of material is not a stress concentrator, at least not in the sense used in engineering or materials science. It may well cause the compressive forces exerted on the bevel to be distributed over a smaller area, but the tensile forces induced by those compressive forces (the bending) will be unchanged. It is those tensile forces which count since it is very unusual for hardened steel to fail in compression when bending.

[Tim Put]

To the original question: for me marking tools and guided tools like planes get hollow ground bevels honed flat (two lines polished).
Anything for which I have to control the depth of cut gets a microbevel of some sort on at least one side (many of my chisels, quite deliberately, have back bevels/ruler trick), gouges in particular I buff to a roughly convex, slippery, steerable shine.

[Stanley Covington]

Before I learned how to sharpen tools from Japanese craftsmen, including a couple of professional sword sharpeners, while a grad student in Japan, I had no idea how sharp a good blade could be. I also had no idea how important it is to get a sharp edge quickly, or how to maintain my blades to maximize sharpening efficiency. I am convinced that secondary bevels, whether on the "beveled edge" of the blade, or on the flat side of the blade (Mr. Charlesworth's ruler technique) are legitimate measures to either obtain an emergency edge quickly or correct a screwed-up blade, but they are not efficient long-term strategies for keeping one's tool's sharp. In fact, I believe them to be an embarrassment in most cases. Certainly, if I had made a habit of using secondary bevels, the old boys that taught me would have mocked me for being like a "woman sharpening her kitchen knife." However, I also learned something about sharpening from academia during my student days. A fellow grad student in another Professor's "research room" did a very scientific study comparing the "cutting efficiency" of plane blades using traditional flat bevels, blades with secondary bevels, and blades with rounded bevels. The edges were sharpened professionally to a defined level of sharpness confirmed by statistical microscopy. Various types of wood and plastic were used in the experiments. I recall hinoki, sugi, and akagashi. The conclusion in his thesis was that the test material did not care about the shape of the blade; all that mattered was the angle of the blade where it met the test piece, and its sharpness. However, the thesis did note that, based on the number of strokes on the stones, the flat bevel was the quickest to reach the required testing sharpness, and the rounded bevel was the most time consuming. In any case, a flat bevel is what I prefer. I will use a secondary bevel to correct a blade that has too low an angle, or the equivalent of the "ruler technique" when the flat of the blade has pits or deep scratches, but under any other circumstances, I would deem such measures to be a waste of time and steel. For what it is worth. Stan

[James Owen]

The only tools that I put a secondary bevel on are mortise chisels; on the rest of my edged tools, a single-angle, flat bevel works fine, and has the virtue of being quick and simple to freehand sharpen.
Like Michael Ray Smith, I also put a convex bevel on my drawknives, and for the very same reasons.

[David Weaver]

Are you guys who are using a single bevel hollow grinding the bevel?

If there are as many people honing a single bevel by hand, it would suggest that maybe there's room for someone to make a manufactured laminated replacement iron. The only current one I can think of for western tools is Tsunesaburo, but it is an iron that's exceptionally fine, hard wearing, but that you can keep in good shape without ever using a coarse stone because it's laminated..and very thin.

[John Coloccia]

Are you guys who are using a single bevel hollow grinding the bevel?

If there are as many people honing a single bevel by hand, it would suggest that maybe there's room for someone to make a manufactured laminated replacement iron. The only current one I can think of for western tools is Tsunesaburo, but it is an iron that's exceptionally fine, hard wearing, but that you can keep in good shape without ever using a coarse stone because it's laminated..and very thin.

I've switched everything to a flat bevel. Everything was hollow ground, but I sold the Tormek and switched to a Worksharp for establishing my bevel, so it's all flat now. For me, the key to working efficiently with a flat bevel is to keep the tool sharp at all times. I hone and strop compulsively. Unless I actually screw up an edge by damaging it, that's sufficient to keep my tools sharp for a long time. Really, it's doing the same thing as a good sharpening, except I'm taking off a tiny amount of material very often, as opposed to taking off a lot of material not so often. That, and my tools are always ridiculously sharp, which makes me happy :)

I'm going to start adding some Japanese tools to my collection. I could really use some nice Japanese paring chisels. That metal gets even more ridiculously sharp. I wonder how the new powdered metal stuff is?

[Jason Coen]

Are you guys who are using a single bevel hollow grinding the bevel?


On my bench chisels and paring chisels, yes. On plane irons and mortise chisels, no.

[David Weaver]

I wonder how the new powdered metal stuff is?

It has more of a tendency to hold its wire edge at high grit than japanese steel (so it doesn't feel as sharp straight off the stone), and is more picky about the stones that it likes. If you're using green stuff, though, I don't know how much difference it would make. A strop should rip the wire edge off of anything sharpened on a fine stone, and cut it off if it's a loaded strop.

All of the japanese parers I've used (three different brands, none of them extremely expensive) have had more of a silky feel when paring than anything else I've used, like vintage buck chisels, but they are harder and hold up better (maybe ideal for your regimen because of it), and are still easier to sharpen without a grinder because of the lamination.

They are not necessary, but they are total sensory indulgence when they are sharp.

[Chris Griggs]

Totally see where you're coming from John. I have moments where I think about getting some nice japanese chisels just because I get tired of regrinding hollows but am too impatient to want to hone flat bevel of hardened steel.... though I have a couple of my main user chisels that are due for a regrind, perhaps I will let them stay flat and give John's constant stropping a try...

[Peter Hawser]

If anyone is new to sharpening this thread ought to make everything crystal clear :)

[Tony Wilkins]

If anyone is new to sharpening this thread ought to make everything crystal clear :)

D'oh - that be me ;)

[Gary Herrmann]

I guess I'm still experimenting.

I have micro (secondary or whatever) bevels on my mortise chisels.

Flat bevels on my LNs.

Hollow ground on my vintage firmers and butt chisels - mostly because they required edge reshaping.

[Dave Hanningan]

There's a guy named Paul Sellers, has been woodworking for over 40 years and does his without micro bevel has a video on Youtube, uses 3 grits of diamond stone and strop with chromium oxide I believe on his smoothing planes and chisels by hand might do it on others blades. And he uses them practically every day. His approach that I like is keep it simple, and get back to work. I assume its more of a practical approach to sharpening for those who work on fine joinery a lot.

[Phillip Dejardin]

There's a guy named Paul Sellers, has been woodworking for over 40 years and does his without micro bevel has a video on Youtube, uses 3 grits of diamond stone and strop with chromium oxide I believe on his smoothing planes and chisels by hand might do it on others blades. And he uses them practically every day. His approach that I like is keep it simple, and get back to work. I assume its more of a practical approach to sharpening for those who work on fine joinery a lot.

I use a modified version of Paul Sellers' method and it works very well. However, his approach effectively produces a micro-bevel. Technically speaking, it's a convex bevel but the effect is basically the same. My method is a hybrid of sorts. I have a primary and secondary bevel (not a micro) and then I finish off with a Sellers' "convex-lift" if you will. Works very well for me. I don't use Charlesworth's ruler trick because I could never get the same results as I did with the convex micro-bevel.

[Tom McMahon]

Flat bevel, convex bevel, secondary, micro it doesn't really matter. What matters is are your tools sharp enough to do what you want them to do. If not try something different until they do. It also shouldn't take more than a few minutes to sharpen a tool and get back to work.

[Jim Matthews]

Find the Paul Sellers videos on this topic.

It was a revelation to me, and MUCH easier to manage.
+1 on the abrasive-charged strop.

http://paulsellers.com/2012/01/sharpening-chisels-forget-weaker-micro-bevels/

http://www.youtube.com/watch?v=a6ykVzL2VAM

http://www.youtube.com/watch?v=vvTcReENk9g

My favorite part of this is that I need not regrind my existing steel to get to this.
Following this method, the existing hollow grinds are slowly being lost to
the growing convex bevel that will replace them.

[Mike Tekin]

For those who use a convex bevel or a flat grind, is it still relatively quick to sharpen with thicker irons like veritas and lie nielsen plane irons as well as Hock, IBC, etc? As an example, I seem to like Paul Sellers approach, but I only see him using it on softer metals and/or thinner vintage plane irons.

I'm trying to keep it sharp and simple




Find the Paul Sellers videos on this topic.

It was a revelation to me, and MUCH easier to manage.
+1 on the abrasive-charged strop.

http://paulsellers.com/2012/01/sharpening-chisels-forget-weaker-micro-bevels/

http://www.youtube.com/watch?v=a6ykVzL2VAM

http://www.youtube.com/watch?v=vvTcReENk9g

My favorite part of this is that I need not regrind my existing steel to get to this.
Following this method, the existing hollow grinds are slowly being lost to
the growing convex bevel that will replace them.

[Phillip Dejardin]

For those who use a convex bevel or a flat grind, is it still relatively quick to sharpen with thicker irons like veritas and lie nielsen plane irons as well as Hock, IBC, etc? As an example, I seem to like Paul Sellers approach, but I only see him using it on softer metals and/or thinner vintage plane irons.

I'm trying to keep it sharp and simple

All my plane irons are A2 Hocks, and the convex bevel is very quick, easy and works like a charm.

[ian maybury]

I'm only starting into serious sharpening, but to my mind the real issue is what works and when and why, and what doesn't and when and why. i.e. lots of us using one or other technique isn't necessarily much of an indication that any particular method is superior. (less labour intensive maybe, or easier to get a result with, or whatever)

It'll take more experience for me to form a user based view on the topic, but based on reading it seems likely that one of the biggest issues in sharpening is the way that wear bevels create the need for the whole business of working a used blade back to truly being the meeting of two parallel surfaces. It makes sense to use some sort of micro bevel local to the edge on e.g. a plane to overcome this, but it's not so clear what the solution is for a chisel that needs a flat back to work properly.

The other issue that gets floated is that the Japanese preference for a single bevel arises out of the weakening of the edge that follows hollow grinding.

Wonder how the various methods stack up in terms of pros/cons/needs and trade offs.....

ian

[Jason Coen]

it's not so clear what the solution is for a chisel that needs a flat back to work properly.



Two thoughts:
1. Just accept that your chisel edges may not be as perfect as your plane irons that receive a small, extremely low angle back bevel.
-or-
2. Toss the idea that chisel backs have to be perfectly flat behind the cutting edge. Personally, I think the notion that chisels shouldn't have any sort of micro back bevel at the cutting edge to be one of those dogmatic theorems that sounds better than it is. I'd love for someone to show me the practical difference in use between chisels that are flat to the edge and chisels that have been "ruler tricked". Side by side, I doubt anyone could tell a functional difference between the two.

That said, I started using the "ruler trick" (thank you Mr. Charlesworth) on plane irons about a year ago just to see how I liked it. I'm still using it and don't plan to stop. I haven't used it for chisels yet, but I see no real reason not to, either.

And I don't know that ruler tricking Japanese chisels would be worthwhile, as there is much less material there to polish than what is found on Western chisels.

[Joey Naeger]

I think the one thing everyone can agree on is that the best way to keep a blade sharp is to not let it get that dull to begin with. This means stopping your work to touchup an edge. For me, I find relying on a jig to be a real barrier. I tried Brent Beech's sharpening method for a while, but ultimately found that I would wait too long between honings and my blades would require a lot of work. Whatever extra efficiency that sharpening method has was completely nulled by how inconvenient it was to stop and sharpen. I've been hollow grinding and using waterstones or some time now, and find that I sharpen more often and that it's fairly quick and painless. If I microbevel, it will be one or two free hand strokes on my finest stone. Small enough that a single stroke on my coarse stone would make it disappear.

[John Coloccia]

Two thoughts:
1. Just accept that your chisel edges may not be as perfect as your plane irons that receive a small, extremely low angle back bevel.
-or-
2. Toss the idea that chisel backs have to be perfectly flat behind the cutting edge. Personally, I think the notion that chisels shouldn't have any sort of micro back bevel at the cutting edge to be one of those dogmatic theorems that sounds better than it is. I'd love for someone to show me the practical difference in use between chisels that are flat to the edge and chisels that have been "ruler tricked". Side by side, I doubt anyone could tell a functional difference between the two.

That said, I started using the "ruler trick" (thank you Mr. Charlesworth) on plane irons about a year ago just to see how I liked it. I'm still using it and don't plan to stop. I haven't used it for chisels yet, but I see no real reason not to, either.

And I don't know that ruler tricking Japanese chisels would be worthwhile, as there is much less material there to polish than what is found on Western chisels.

It's much easier to control a flat backed chisel when you're paring. Even the slightest microbevel will essentially have you teetering on a point and can make the chisel much harder to control.

[Jason Coen]

It's much easier to control a flat backed chisel when you're paring. Even the slightest microbevel will essentially have you teetering on a point and can make the chisel much harder to control.

I agree with that being the idea, I just don't see that being the case in practice. Granted I haven't spent a huge amount of time paring with a chisel that's been ruler tricked, but I have initially set up vintage paring chisels in this manner when I needed them working quickly. When the project was done, I set them up like normal with a flat back, and I have to say I couldn't discern any difference in function. Maybe I'm just a moron (always a legitimate answer). :D

[Phillip Dejardin]

It's much easier to control a flat backed chisel when you're paring. Even the slightest microbevel will essentially have you teetering on a point and can make the chisel much harder to control.

I've had the same sort of doubts that Jason has. Is there really the risk of "teetering" using Charlesworth's ruler trick? We're talking about a miniscule bevel that itself can't be seen with the naked eye, except for a slight (thread-like) polished reflection. A pencil line is probably thicker than a microbevel. How would it be possible to teeter on something that minute? The slightest tilt of the hand while paring certainly introduces more variation than a microbevel. Besides, the reference surface on the back of the blade encompasses a much more substantial area in contact with the wood while paring.

edit: the above it not meant as a criticism of anyone's sharpening techniques. I'm the last person in a position to make those type of judgments. The stated reasons for avoiding a microbevel on the back of chisels haven't made much sense to me, which is my problem, so I'm obviously missing something here. That's all.

[Jim Koepke]

I think the one thing everyone can agree on is that the best way to keep a blade sharp is to not let it get that dull to begin with.

Not sure if everyone agrees, but this my way of taking care of my blades.

My system seems to be working for me. There may be a better way, but someone is going to have to demonstrate that some other way is actually better.

The Sellers method is interesting. On water stones it can be a disaster if the blade is lifted just a bit too much on the forward stroke. As long as the edge is sharp, the convex profile could be likened to a multitude of micro bevels.

Hollow grinding is a great aid to free hand honing. The draw back is the need for a grinder. Many times blades are messed up by a grinder when done by someone who doesn't know the technique. Many of my chisels and planes came with obvious signs of being sharpened on a grinder by someone who thought it was the final step instead of the first step.

Bottom line is if what you are doing is working well, why change it?

If it isn't working well, then one must determine what is the cause of the problem. Changing from one method to another may not be the answer.

Clearly micro bevels, back bevels, ruler tricks, hollow grinds, flat bevels and apple seed bevels (my recollection is that is what the Sellers method was called before he demonstrated it) all work in their own way. So the best way to determine if you will like or benefit from any of these is to give it a try.

jtk

[John Coloccia]

I've had the same sort of doubts that Jason has. Is there really the risk of "teetering" using Charlesworth's ruler trick? We're talking about a miniscule bevel that itself can't be seen with the naked eye, except for a slight (thread-like) polished reflection. A pencil line is probably thicker than a microbevel. How would it be possible to teeter on something that minute? The slightest tilt of the hand while paring certainly introduces more variation than a microbevel. Besides, the reference surface on the back of the blade encompasses a much more substantial area in contact with the wood while paring.

If you don't feel having a flat backed chisel is useful, then don't bother doing that, I guess. I always encourage everyone to try for themselves and see what works for them. I'm really just not into theorizing about this stuff online. I just let results guide my process. Not everyone gets the same results with the same techniques.

[Paul McGaha]

Per David Charlesworth, Don't use the ruler trick on a chisel. As the chisel back does the same job as the sole of a plane.

I use secondary bevels on everything, polished up to about 12,000 grit and the main bevel only sharpened to about a 1000 grit or so at the most.

PHM

[Phillip Dejardin]

If you don't feel having a flat backed chisel is useful, then don't bother doing that, I guess. I always encourage everyone to try for themselves and see what works for them. I'm really just not into theorizing about this stuff online. I just let results guide my process. Not everyone gets the same results with the same techniques.

My apologies, John. I didn't intend my response to come off as a challenge.

[John Coloccia]

My apologies, John. I didn't intend my response to come off as a challenge.

None necessary, Phillip. I wasn't offended in anyway. The only thing that really matters is results and however you get there is your business. All the hand wringing about the effects of a flat chisel back really mean nothing if yours has a micro bevel and you get the results you seek.

[Jason Coen]

Per David Charlesworth, Don't use the ruler trick on a chisel. As the chisel back does the same job as the sole of a plane.


I understand the theory. I'm just not sure in actual practice that anyone can tell the difference between a chisel with perfectly flat back and one with a 1° or less bevel. Maybe people really can and I'm just ham fisted to notice? Certainly possible.

And related to this, where are all the antique paring chisels with flat backs? I've never seen one...ever.

[ian maybury]

Ta Jason. My gut says stay with a flat back too, but in practice the outcome probably depends a lot on the sort of cut being made. The basic issue with a bevel on the back is presumably that (a) the chisel will cut at whatever height above the back, and (b) that the resulting micro face at whatever angle will tend to deflect the chisel upwards.

No doubt i'm missing the obvious, but why would you (that's you plural/in general = anybody - not personally - sorry if it read that way) ever want to sharpen with a convex bevel? It probably doesn't matter in that it's only the immediate cutting edge that the wood sees, but either way that last section just before the edge surely needs to be at the same angle as a flat bevel to cut the same way? i.e. it's not like it gets you off the hook on either (a) the volume of metal that needs to be removed to get back through the wear bevel to give a fresh edge, or (b) the need to accurately control the sharpening/honing angle?

The coarse diamond plate is going to shift material fairly quickly, but surely that's down to the plate and not the convex bevel method?

There's a mention in the video of not needing a flat plate/stone. Not sure i see either how it changes any of that either. A diamond plate will stay pretty flat, but surely that's again the plate and not the convex bevel method?

Finally on stropping on leather, especially using heavy pressure. Since the leather surface is not hard/rigid then surely it must cause some minimal degree of curving and/or bending of the edge very near to the edge?

ian

[Jim Stewart]

There are different ways down the road to get to the same place. I don't know if one is better than the other, but I know how I do it. I do it my way because it is very time efficient and it gets tools razor sharp. I am addressing chisels and squared plane irons here.
1. I sharpen hollow-ground on a Tormek. I don't finish the edge on the Tormek. I just get a square edge, and a hollow ground surface that is completely a new surface.
2. I go to a 4000 Norton and I carefully use the two outside edges as my guide. I take three to five passes here until I have established a flat on both edges of the hollow ground surface.
3. I go to the Norton 8000 for the same number of strokes.
4. Same process on the Spyderco Ultra-fine.
5. I strop often if that does not work I go back to the Spyderco.
6. At some point when the edge needs to be renewed I go back through steps 2-4.

The end result is that I don't use the Tormek often. It really takes very little time to go through steps 2-4 or bench stropping. I use a piece of Horse hide glued on a Maple block. Sometimes I use a little Simichrome. I get razor sharp mirror edges. I don't have to mess with jigs. My edges don't break because I am in effect establishing a micro bevel. Jim

[Jim Koepke]

And related to this, where are all the antique paring chisels with flat backs? I've never seen one...ever.

Only a few of mine have come with flat backs. Most of them look like a tool that was once used by someone who knew how and then laid around until a later heir decided to see if it would cut nails. After all, where did the woodworkers from grandpa's day get cut nails?

As Ian suggests, excess stropping can lead to a rounded arris.

Chris Pye instructs in one of his books, 5 to 10 strokes on a strop is all one should use at a time.

It just goes to show that different methods work for different people. Find what works for you and use it.

jtk