Wear bevels, micro bevels & sharpening - latest thinking?

[David Weaver]

I spent about an hour writing a note to him. His response was very dismissive of my methods and he failed to even thank me for my efforts to organize and present my thoughts. I don't think he has much experience in real woodworking.

A browsing through the showcase of various sharpening jigs that are featured there shows bias toward making sharpening some sort of scientific experiment instead of a display of basic craftsman's skills.

I find the bits and pieces about the various wear profiles of the steels instructive, but the overly jigged sharpening is something I can do without.

I read something on there that was not correct about double irons and sent a fairly thorough explanation of what was wrong and why, I never looked to see if it would be changed, but it is discouraging to see information that is outright wrong, and asserted bluntly with such assumed authority. Especially among some otherwise useful and interesting material.

[Steve Voigt]

I use a single flat bevel. I start with a coarse stone every time I sharpen in order to get past the rounded edge; I think this is the most efficient way.

Hi Warren,
I was wondering how you arrived at the flat bevel method. Is it something you gravitated to from reading historical sources, or just from trying different methods and liking that best?

[Winton Applegate]

I am getting the vapors from it all. It is just toooo much. I have to go lie down until it passes.

hone the primary bevel back enough to definitely get past the wear bevels

YES !
But
just the micro bevel back past the wear bevel. Not the primary which may be twenty degrees shallower than the secondary/sharpeing angle. With stones that is unnecessary work and wear on the stone. Unless we are power grinding then why not ?
Well I guess I am going to answer my self. Because it wastes the blade material and even a modern style blade (as opposed to a laminated) is expensive and worth preserving as much as possible.

micro bevels on the back side

Freekin’ three of them ? ? ?

NO
NAH
NOPE

That’s like saying “Oh look . . . a wear bevel . . . we better take that off . . . oh look . . . the wear bevel has disappeared . . . I wonder why ? I wonder who stoll’ it ? We better put it back on.

NO
NAH
NOPE

As far as the Japanese blades I use micro bevels on them (on the bevel side) if I need to steepen up the edge. Sharpening on the whole bevel with the way the softer steel acts as a jig and all is very cool and fun to do but I am not going to grind off all that fancy steel just so I can have a steeper angle for a while so I wind up micro beveling and sharpening it just as I would say an A2 blade. BLASPHEMY ! I know.

I feel faint . . Beulah . . . Beulah . . . oh there you are dear.
Beulah . . . peal me a grape.

[Bob Jones]

You can't go wrong with the words from Warren. I have found that not everyone means the same thing with "flat bevel". Some people mean it literally - a single flat face over the whole bevel. Other people mean hollow grind and then hone at the same angle - eventually it flattens out, but never fully because you regrind (I do this).

I am experimenting (I'd say maturing) into a variant of this method. I hollow grind on a 8in wheel with every tool, every time I sharpen. I leave the faintest line that I can see, unless I need to address the shape of the edge - then I go through the edge just enough to get the shape I need. I then hone all the way through the edge until I get a burr on the back and I have the edge shape I want.
- With tools that are used free-hand (like chisels and drawknives) I hone at the same angle as the grind (flat-ish bevel). I think this gives better control of the tool because I can ride the entire bevel and the cutting edge matintains consistent contact with the wood. Trying to ride the micro-bevel is much more difficult. Hope this makes sense. I got this idea from a famous spoon carving book.
- With irons that are captured (planes and spokeshaves) I hone a microbevel using a guide. It's fast, easy, and does not cause a loss of control because the tool is captured anyway.

With either method I use zero back bevel (just hone flat each time) and I am 100% confident that I am going through the wear bevel every time.

Warren - I'd be glad to post whatever you put together on my blog to save it. Just send it to me. And I may get around to the Roubo lathe build this year. I found some nice 4x4 white oak posts...

[Kees Heiden]

Mr. Beach has a lot of conjecture on his website. He kind of lost contact with the real world somewhere in his "scientific" meanderings.

I have not much experience with bevel up planes, but have no trouble to keep my blockplane sharp. No backbevels. Just leaning a bit heavy on the blade near the edge takes care of it in no time. But, like Warren writes, it's better to not let things run out of hand in the first place.

On a bevel down plane it's much simpler. You remove the important clearance side bevel while working on the bevel. And it doesn't matter at all if you don't remove all of the upper side wear bevel, as long as you remove the burr from sharpening. And again, when you lean a bit heavy on the blade, near the edge, that isn't a problem either.

[ian maybury]

Think it's time for me to get on with some more sharpening. I'm just appreciative to have learned that everybody here seems to agree that it's important to do enough work to fully hone away both wear bevels to get to the classic cutting edge comprised of two polished flat faces intersecting at an appropriate angle - that there's a potential pitfall in the form of a misleading wire edge that may first appear (especially if the tool is let get very blunt) a bit before that point is truly reached. Also that there's a few viable variations in use of honing bevels that can achieve this. (planes and chisels differ anyway)

There's clearly lots of caution about the complexity of and genuineness of the need for the multi bevel approach (that it's unlikely that it's going to deliver a unique result that can't be achieved with fewer sharpening bevels), so thanks for the heads up. My personal inclination is as before to keep it simple, even if that entails a little more work. My thanks to Mr. Beach too for bringing these issues to my attention.

Either way it's 100% clear as Warren and others that after that there's no escaping the hands on work needed to evolve simple and practical working and sharpening procedures that deliver for each of us, and that there's a lot about it that's hard to capture in discussion without causing confusion and/or drowning in words. We talked before about this being where the magic happens in the context of your Chinese video guy David....

Thanks again guys...

[Warren Mickley]

I was wondering how you arrived at the flat bevel method. Is it something you gravitated to from reading historical sources, or just from trying different methods and liking that best?

About historical sharpening. Moxon mentions hollow grinding, but I don't think 18th century cabinetmakers did much hollow grinding on chisels and plane irons. 18th century irons were thin, like 1/8 inch and firmer chisels were considerably thinner. The grindstones were large, like 22 inches in diameter and larger and were without fancy tool rests and jigs. Theoretically one could get a hollow .0007 deep on a plane iron but try it at home some time.

Grinding was done on both a wheel and a large flat slab. I think workers used several methods of honing.

1. Honing on a small bevel and periodically grinding at a lower angle to keep bevel small.

2. Sharpening full flat bevel as the Japanese do.

3. Honing full bevel, but giving more pressure toward the edge. In this method the honing angle very gradually increases over time and at some point grinding is done to bring back a lower honing angle. This is a very workable method that I have used on occasion when in a big hurry.

I experimented with these methods when I was young and gravitated toward the flat bevel because of its consistency. This was before most of us were aware of the Japanese methods. I am a little cloudy about what jigs were available forty years ago, but I never had much interest in that.

[Mike Holbrook]

It seems to me that the hollow ground vs convex vs flat grind discussion is a relatively hollow argument. Isn't flat largely a theoretical term in most sharpening, certainly in hand sharpening? Assuming we are not going to make any bevel completely flat isn't the question more whether or not we want to err to the convex or concave side? At my skill level I find it difficult to maintain a completely consistent bevel across an entire face, regardless of whether I am using a Tormek like Derek or a flattened stone. If one wants to impart rounded edges or a curve to a plane blade the different pressure and amount of abrasion on the edges would not seem to lend themselves to a consistent bevel either.

I understand that flat might be something of a rough goal but, I'm not sure the final result of a large wheel like the ones that come on Tormek's or old larger grinding stones is something to get excited over. It is possible to vary the pressure on the lower and upper side of a "hollow" bevel and "flatten" it. The reason I do not get excited about "micro bevels" is I seem to end up with an assortment of them anyway. Having purchased quite a few old, well used tools over the years I do not remember finding one with a perfectly flat, concave or convex bevel. I think it safe to assume, I am not the only one who has a problem making perfect bevel or micro bevel angels.

[Steve Voigt]

About historical sharpening. Moxon mentions hollow grinding, but I don't think 18th century cabinetmakers did much hollow grinding on chisels and plane irons. 18th century irons were thin, like 1/8 inch and firmer chisels were considerably thinner. The grindstones were large, like 22 inches in diameter and larger and were without fancy tool rests and jigs. Theoretically one could get a hollow .0007 deep on a plane iron but try it at home some time.

Grinding was done on both a wheel and a large flat slab. I think workers used several methods of honing.

1. Honing on a small bevel and periodically grinding at a lower angle to keep bevel small.

2. Sharpening full flat bevel as the Japanese do.

3. Honing full bevel, but giving more pressure toward the edge. In this method the honing angle very gradually increases over time and at some point grinding is done to bring back a lower honing angle. This is a very workable method that I have used on occasion when in a big hurry.

I experimented with these methods when I was young and gravitated toward the flat bevel because of its consistency. This was before most of us were aware of the Japanese methods. I am a little cloudy about what jigs were available forty years ago, but I never had much interest in that.

Thanks for the reply Warren. It's interesting; in the machine shop, I was trained to grind primary bevels on lathe tools on a big grey wheel (about 12" diameter and 2" thick) freehand, without using a toolrest, and I agree that it's hard to do that with much precision.
I wish I knew more about historical references on sharpening. I know what Moxon says, and Nicholson describes method (1) above. Does anyone know what Roubot, Salivet, or other contemporary sources say?

[Adam Cruea]

I use a single flat bevel. I start with a coarse stone every time I sharpen in order to get past the rounded edge; I think this is the most efficient way. I think it is best to use the same routine every time and to sharpen at the same stage of dullness. The back needs to be abraded regularly, not so much for wear as to work the burr and to polish out the scratches which accumulate with use. The ruler trick seems like an idea for a guy who is constantly trying out new plane irons, but it is not necessary for day to day woodworking. I have only used about nine plane irons since 1970 for my bench planes.

On the bevel, the scratches from the coarse and intermediate stone have to be removed during the refinement stage of sharpening. I think this is faster and easier if the stones are not too harsh. The best way to determine if the effects of coarse and intermediate stones have been polished out is by gauging the performance of the tool. This takes experience and careful discernment.

I got an email from Brent Beach in 2007 asking if I would detail my sharpening methods. I spent about an hour writing a note to him. His response was very dismissive of my methods and he failed to even thank me for my efforts to organize and present my thoughts. I don't think he has much experience in real woodworking.

Not that it matters from a dude that's been alive shorter than you've been woodworking, but this is what I do.

Single bevel. I may take an iron or chisel to a grinder if I'm feeling impatient. I just think and realize past woodworkers didn't have these fancy super-micro bevels on top of micro-bevels on top of more bevels and they did just fine. Why do I need to do it? I'm in this to make sawdust and neat-o wooden stuff, not indestructible edge tools.

I start with my normal coarse stone (unless I tried to sword fight and really honked up an edge), then proceed through my stones to a strop. And I do agree with another statement. . .if you have to remove .001" of steel, you waited way too long to sharpen. While I used to wait this long, over time I realized "oops, that's kind of not a good idea".

[Warren Mickley]

Thanks for the reply Warren. It's interesting; in the machine shop, I was trained to grind primary bevels on lathe tools on a big grey wheel (about 12" diameter and 2" thick) freehand, without using a toolrest, and I agree that it's hard to do that with much precision.
I wish I knew more about historical references on sharpening. I know what Moxon says, and Nicholson describes method (1) above. Does anyone know what Roubot, Salivet, or other contemporary sources say?

Roubo shows a large flat piece of sandstone for grinding in the first part of L'Art du Menuisier. This was a shared tool provided by the owner of the shop.
roubo sharpening.jpeg
In the third section of the third part of the work, Roubo discusses marquetry and veneer workers and says that some of them use a grinding wheel, and some use a flat stone like most other woodworkers. He describes the grind stone as two feet in diameter and two or three inches wide in a shallow trough. He also mentions using Turkey stones with oil and how a good quality stone (not so many flaws) was expensive, but worth the price.
Here is plate 280 showing grinding wheel and oilstone.
rpubo oilstone.jpg

[Malcolm Schweizer]

My two cents: I used to do a single microbevel on the flat honed primary bevel, and flatten the back meticulously rather than the ruler trick, mainly because I'm a big nerd who enjoys the challenge of getting the whole back flat and not because the ruler trick isn't worthwhile.

One day I bought a used bevel-up plane and the guy included a hollow ground blade. Oh my, that was so much easier to hone. Suddenly I wanted a Tormek, which I got last week, and will probably hollow grind all my plane blades, then put a 2 degree extra microbevel on for the final edge. Chisels will remain flat honed.

I am admittedly new to this multiple bevel idea. I need to read up on this, but it sounds to me like a whole lot of fuss. Further comments witheld until I give it a fair try.

[Robert Hazelwood]

I use two bevels. The first is a low-angle primary grind of about 20 degrees, which only sees a belt sander. Its purpose is simply to reduce the size of the actual edge (secondary) bevel so that I am only working a small area with the stones. I will start out with the secondary bevel quite small, between 1/32 and 1/16 probably. Once it gets too big, maybe over 1/8", I regrind at 20 degrees until the secondary bevel is almost, but not quite, removed. The secondary bevel is usually at 30 degrees for plane irons. This is analogous to what most people would do with a grinding wheel, producing a hollow grind which has the same work-saving effect as the primary flat grind I'm using.

At least with decent stones, I think if you keep the secondary bevel small enough you don't really need to do a third (micro) bevel. It would be a bit too much me if I had to re-clamp the blade in a jig just for that microbevel. If anything I would just raise up the back of the blade slightly on the last few edge-trailing passes with the fine stone to get a micro bevel, but I haven't really found the need.