A Unified Theory of Honing and Stropping?

Well, maybe not. Sounded cool though.

The idea has been developing for several days now, and just sort of gelled on my drive to work today. It derives it's basis from all that I know and have learned with much trial and error over the years. Am I making too much out of nothing? Probably, but I'm sure the SRP jury will soon tell. Is this really new? Again probably not. But maybe put together in a new way.

So here's my thought:

1) Honing - Basically honing is a pushing movement causing forces to go in the direction of the razor edge towards the back or, spine. This not only creates the micro-serrations, but also (note: my theory next) slightly crumpling (Edit: since it was pointed out that "crumpling" may not be the best word, I've decided that "compacting" may be more accurate) the delicate edge of the razor.

Also, the micro-serrations are created at an angle, preferably 45 degrees downward from point to heel of the razor. If you think of all the different angles the micro-serration could take, the downward 45 deg, seems to me to be the most effective for cutting (I'll go into why I think this at a later time).

So the end result of honing: downward angled, slightly crumpled micro-serrated cutting teeth.

2) Stropping - the next thing needed is to un-crumple (Edit: un-compact) the edge and draw/ pull the "teeth" out as straight and as flat as possible. We would want to do this as much along with the angle of the teeth/ striations as possible. Stropping forces that go across the striations might tend to deform, or somehow negatively affect the cutting edge. Also, we need to generate enough force to do this. If I remember correctly, part of the force equation includes velocity. I've recommended for some time speed stropping and now it makes sense. It seems that a slow stropping stroke just would not have the force necessary to pull the edge out sufficiently.

There are a couple of different ways I can think to generate directional force along the lines of the angled teeth. One way would be to strop as if you were back-honing on a hone. I don't believe that this would offer enough space to develope the velocity needed to draw out the teeth and edge in between the teeth sufficiently.

The other way is the sweeping X pattern that I have described many times before. This does allow a high velocity stroke, and by variably angling the razor throughout the stroke, the forces remain generally along the 45 degree downward angle of the teeth.

So there it is in a nut shell. I have more to add, but need to clock in here at work. I'll let the community here have at it for a while and see if anyone has something to say or add :w


Scott

All this time I've been guessing that it would be best to strop against the teeth lines from honing. No wonder I haven't been able yet to get a close shave against the grain under my chin, my micro-serration theory was fundamentally flawed!

The sky is the limit now, baby!

Are you looking for different viewpoints? I have a few . . .

Sure, different view points, tear it appart, ingnore it, make fun of it, whatever...

That's why I posted it. If something comes of it great. If not, no biggie. Maybe someone will get something from it, maybe no one will. Not going to change anything for me either way.


Scott

There have been many photomicrographs (sp?) that show the only thing going on at the cutting edge during the honing process is the formation of micro serrations, no crumpling.

Stropping realigns an edge that has gotten "folded over" or bent out of alignment by use. I think in the case of razors it also has a "smoothing"effect, as in, it may slightly dull the teeth providing a more comfortable edge.

edit: I mean no offense, just presenting what I have come to understand from my own as well as other people's experiments.

Yes and I think creating a painting can be reduced to the same level as you state. Afterall its just paint and brushes and pushing a brush across a canvas right?

Seriously though there have been these discussions about whether honing is a science or an art. To me there are just too many variables involved. To know what to do and what to use at the right time can't be reduced to some formula. For most of us things keep changing with every razor. Maybe the aim and mechanism are the same but getting there is like the guy doing the painting. Its his skill with the stuff that creates a masterpiece.

Yea you could say in the old days people had but one hone and managed to maintain their razors and most didn't have much skill but I'm not convinced that alot of guys ever had truly shave ready razors. Most probably used razors that were so-so and relied on now and then professional honing jobs which were much easier and cheaper to get than now.

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Originally Posted by Russel Baldridge

There have been many photomicrographs (sp?) that show the only thing going on at the cutting edge during the honing process is the formation of micro serrations, no crumpling.

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Hmmm, crumpling is just a word I chose. Maybe not the best. The concept is that honing pushes metal in towards the edge while high velocity stropping pulls it back out, and then some.

Any photomicrographs confirming/ discrediting that possibilty? Maybe no-one knew to look for it?


Scott

Prof. John Verhoeven has a paper on sharpening that includes electron microscope photographs at 3000x, taken from both sides and looking straight down at the edge. He's got shots of straight razors, commercial razors, and his own edges, honed on waterhones, diamond paste, 0.5 chromium oxide, felt, leather, etc. These photos were high enough magnification and clarity for him to measure the width of the edge with an precision of less than a tenth of a micron.

None of these photos show either crumpling or teeth at the grit levels we use for razors - if anything, the edge simply looks "torn" where the steel failed where it got too thin.

FWIW, the edge width of the straight razor was essentially the same as the commercial blade and the same as the other edges he honed himself. It looks like you can only get so sharp before you hit the limit of the steel. Harder steel let you get a bit sharper, and finer grit hones or pastes gave you less variation along the edge so instead of the edge ranging between 0.5-0.7 microns you might get 0.50-0.55 microns.

Unfortunately he doesn't have photos of edges before, immediately after shaving, and 24 hrs after shaving. But my theory is that the leather strop aligns the edge and the linen strop mostly knocks off the corrosion. Steel swells when it turns to rust, so even the smallest bit of corrosion on the edge makes the edge feel quite dull. OTOH knocking off the rust can make the edge feel even sharper than it was when it was first honed, a phenomenon I first read about on Arthur Boone's website.

Well, there you go. Hey, I've got nothing better to do with this stuff than play mental gymnastics anyways...

So, for better, or worse, it was worth a shot.


Happy shaving!


Scott

Yes, I was mainly referring to the Verhoeven document. The Zowada website also has nice shots of razors honed on various stones which show the level of polish each stone imparts.

I have come to refer to the jaggedness of the edge as it's "teeth" or serrations or whatever. The point for me is that the edge is as rough as the finest grit used on it, whether or not it actually has serrations in the manner we commonly think of. Not that it matters, just wanted to clarify some vernacular.

And I agree with Bigspendur, even the most thorough explanations and reasoning don't mean squat until you have hands on experience.

But it is good to have discussions like this

I think the honing and stropping issue is much simpler than we think. I agree with a lot of what you say except the idea that stropping aligns the teeth.

I think that stropping merely makes the teeth less toothy. The "imperfections" noted by Voorheeven (and MParker), or teeth, are simply smoothed by the strop, not aligned. I follow A.B. Moler's (1926) theory from The Barber's Manual when he wrote "honing and stropping is given to obtain just the proper set and size of teeth" (p. 40).

I think you can cut teeth into steel with a stone, but I don't think you can align them with leather. I think you just buff them a little smoother and create a sort of tip out of the mess (referred to incorrectly as "teeth"). This becomes even more important when you start to realize there really aren't "teeth" at all. Its more just a polished wedge. Its aligned, but more the way you would "line up" imperfections in a linear path along the edge, not as in aligned teeth.

Thats why in Das Rasiemesser (The Razor) (1939), the author states "the edge which microscopically consists of many parallel steel wires, is malaligned by shaving". I think, historically, this concept has been misunderstood into thinking that we are aligning a series of outer running opposed teeth, when what we are really doing is aligning the edge into an "aligned" or "linear" edge. I think the teeth are sort of there, more as a sort of "mess" that gets buffed down, which we call the "fin", this fin, then creates strop draw as it is dragged down the strop, but I think it is buffed, not aligned crosswise. This is why you can strop at different angles, always get draw, and still get a good shave, regardless of the honing angle used.

Alan,

Read back and I think you'll see that I wrote that the stropping forces align with the angle of the teeth, and not that stropping aligns the teeth themselves.

I know, a fine point.

Also another thought (not just you Alan): who did the honing and stropping in the above mentioned Verhoeven experiments? One person? Several? And how was the honing/ stropping done? All the same method? Did they try different methods? Were they aware that different methods might exist? Might make a difference...

Part of my theory (I wrote that I would get to it later) is that certain types of stropping might obliterate (from smoothing out/ wearing down) the striations/ micro-serrations. If they were present, then stropped away, they wouldn't be there to microphotograph. Would they?


Scott

It seems this is one conversation that is nearly useless without pictures.

By "align the teeth" I meant "make the edge a perfectly straight line", not "equally space the tips of the jagged areas". Have I misunderstood what you were trying to clarify Alan?

Correct me if I'm wrong but strop draw has always just seemed like simple friction to me.:shrug: I mean, a square bar of steel will create draw on a strop as well, no razor edge necessary, no?

The photo is one from a woodworking book where the author tries to put a razor edge on chisels etc. It is a good example of how an edge can be misaligned.

There weren't any teeth in the commonly-understood sense even in the photos where the edge was not stropped after honing, so I don't think it's the case that the teeth or serrations were removed by improper stropping. They just don't exist. I think our persistence in calling the irregularities in the edge "teeth" or "serrations" keeps giving the wrong impression that the microscopic edge looks like a sawblade or a spyderco edge where the honing serrations intersect at the edge. The problem is that these grooves don't intersect any more than the four corners of Khufu do - they just look like it from a distance. The irregularities in the edge may contribute to the cutting action, but I think the only alignment that occurs during stropping is lateral. Verhoeven didn't test stropping on linen but he did test stropping on felt and the electron micrographs showed that the primary effect of the felt was abrasive.

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Originally Posted by Russel Baldridge

Correct me if I'm wrong but strop draw has always just seemed like simple friction to me.:shrug: I mean, a square bar of steel will create draw on a strop as well, no razor edge necessary, no?.

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Yes, but why does the draw increase the longer you strop? Why does the amount of draw seem to be related to the sharpness of the razor, to the extent that some guys can tell how sharp the razor is by how it's drawing? What if anything does draw *do* to the edge? Is it a cause or an effect, or just coincidently correlated? Razors also experience drag on a hone, and on certain types of hones this drag increases as the razor is honed in a manner that seems analogous to strop draw. Is this related to the mechanism that causes draw on strops?

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Originally Posted by Russel Baldridge

The photo is one from a woodworking book where the author tries to put a razor edge on chisels etc. It is a good example of how an edge can be misaligned.

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Those look more like honing burrs to me but yes I think that's the sort of misalignment we're talking about though hopefully not nearly so extreme. Verhoeven has similar photos in his honing article, and he shows the same edge from all three sides so you can get a better idea of the extent of the distortion. I think what Alan is addressing is the common misperception around here over the years that one of the purposes of honing was to put nice even sawtooth structures at the edge, and that stropping is aligning a sawtooth-like structure at the edge by straightening the teeth at right angles to the edge as shown in your photos as well as straightening them out parallel to the edge in a sort of "combing" action. This led to discussions about which hones left the best tooth structure at the edge, whether finer teeth were sharper or wider teeth were stronger, the relative benefits of deep teeth versus shallow teeth when shaving a heavy beard, whether we should be stropping with the tip leading so as not to bend the teeth over each other, etc. I was a vigorous participant in many of these discussions. Looking at the coarse grooves in the bevel under the cheap radio shack microscope it is easy to believe that these grooves would create a serrated or sawtooth structure at the edge, and it took the 3000x shots from the electron microscope to convince me that I was mistaken. But convinced I am, though I no longer know how to explain some of the honing- and stropping-related phenomena I have seen.

We had a long drawn-out and overheated thread about the Zowada photos when he first posted them, but I think those photos are misleading in a number of ways. First because they are an order of magnitude short of the magnification needed, and second because they're optical photographs of something that is notoriously difficult to photograph as anybody that's tried to reproduce them can attest. Minor changes in the lighting can have a huge difference in the way the grooves and edge appear - you can take a photo that shows a perfectly smooth bevel, then move the light a few degrees and suddenly it looks like somebody planted a corn field on the bevel. Even under the low-power Radio Shack microscope the difference between the fabled "black ice" and a "gray plain" is simply the angle of the microscope relative to the honing angle. So while the Zowada photos are a valuable resource they must be interpreted cautiously. The same goes for the Verhoeven photos - there are things that we need to know about that he just didn't test (effects of shaving, effects of corrosion, stropping on leather after a shave, stropping on linen - he did test stropping on leather after honing though, and didn't see any effect on the burr).

This all assumes that Verhoeven, and even Zowada, are competent straight razor honers and stroppers.

And if not?


Scott

No, not completely. Its really the pictures that tell the tale. For example, a disciplined stroke, maintaining edge alignment to keep the teeth in proper opposition, could also simply be producing a better finer edge.

What I think we need to develop is a firm grasp of the characteristics of straight razors and develop a theory from there. As long as there are phenomenon we don't completely understand, then our theories will remain to have holes in them.

For example, a dull razor will not produce draw on a strop, only a sharp one. Also, linen is said to help the shaving edge because its bumpy surface is said to reapply some toothiness to the edge (and that overtime a strop over smoothes an edge). What characteristics we believe should have applicable experiments that go with them, or easily disprove them.

I think we should come to a concensus on the phenomenon and characteristics we see and know.

The razor in the VH experiments were honed by a man who "used a straight razor" and your right Scott that that doesn't exactly mean that he understood striational theory to get the best shave. On the other hand it could simply be that "stropping is king" and that great shaves are simply a product of the best/most stropping technique.

I have found, over time, that some striational theory support like "then its best to use a scything motion" don't really apply very well in practice. The importance of scything seems to reflect simply how sharp the edge is.

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Originally Posted by honedright

This all assumes that Verhoeven, and even Zowada, are competent straight razor honers and stroppers.

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Honing not stropping was the main focus of Verhoeven's paper - he was really trying to look at what the woodworkers were doing since straight razor shaving was and remains a rare curiosity. He included a commercial razor blade and a hand-honed straight razor in his photos because those are good reference examples of the sharpest machine-honed edge and hand-honed edge. But because shaving wasn't his main focus he didn't have any shots of linen-stropped steel or of leather-stropped post-shave steel. He did have shots of a freshly honed edge before and after stropping on leather to see if it removed the burr (it didn't). He repeated the test using felt as the stropping medium (also popular among woodworkers) and found that it did remove the burr - though it was by abrasion and not by breaking it off as was the common theory among woodworkers.

Verhoeven may well be an indifferent honer but his microscope would have told the tale if his edges were markedly subpar. If you haven't downloaded the paper at that link I included in my first post in this thread you really should, because the level of detail in those 3000x photos is quite astonishing.

First off let me say that I am very new to the straight shaving world so what follows is just ideas formed while reading this post and line of comments. I welcome all to pick them apart at will without worry of offending me. I'm a big boy.:D

I would have to imagine that any material that comes to an edge like a straight razor will look serrated at a high enough magnification. Unless it's a perfect crystal lattice, and probably still even then, when you zoom in close enough there is always micro-chipping, fissures, etc. So when you hone you're just removing microscopic particles bit by bit untill you get that edge as close to perfect as you can. The cutting of hairs in my opinion is more of a cleaving effect of a fine edge.

Now as soon as you stop honing oxidation starts in, and we know from peoples experience that oxidation happens extremely fast on a visual level so we can assume that it occurs even faster on a microscopic one. I believe that the friction of stropping scrapes away this oxidation, smoothing out the edge again. A linen strop, providing more friction does so faster and easier. Now over time you are removing this microscopic oxidation causing your edge to round again and reducing it's ability to cleave the hair, thus a touch up is needed.

As far as drag on the strop is concerned this is my opinion on that. You're done honing and right away the oxidation starts, this creates a microscopic rough edge which reduces the total area of contact on the strop. As you strop and remove the oxidation the total area of contact increases and you are in effect getting the razor closer to the strop, on a microscopic level atleast. If I remember correctly there is a physical phenomena in which when two things are placed extremely close to each other they start to pull together, and I mean microscopically close. Similar to the force you feel when you bring two magnets close together without them touching. I feel this increased attraction would cause the increase in drag.

This is my opinion on all this. Right or wrong? Let me know what you think.

Admittedly, then, the Verhoeven studies are not straight razor specific. Extrapolating what happens with wood worker's tools to straight razors seems prone to flaws.

What's needed is the same type of study, but with razors honed and stropped by a variety of experienced straight razor users.

Until then, the Verhoeven work doesn't hold much water for me. I've seen the photos, but for all I know those are photos of crappy edges, in terms of "shave ready" that is.



Scott

I don't know whether or not this is correct, but I have a suspicion that some of what people say they feel while stropping is like what dowsers feel when they want to believe they are nearing their goal. Placebo effect / power of belief / etc. I also find it hard to believe that physically observable sharpness can be compared to effective sharpness for cutting hair on one's face. However I would be delighted to be found wrong on these points, as it would magnify the mystique of straight razor sharpness for me!

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Originally Posted by hoglahoo

I don't know whether or not this is correct, but I have a suspicion that some of what people say they feel while stropping is like what dowsers feel when they want to believe they are nearing their goal. Placebo effect / power of belief / etc. I also find it hard to believe that physically observable sharpness can be compared to effective sharpness for cutting hair on one's face. However I would be delighted to be found wrong on these points, as it would magnify the mystique of straight razor sharpness for me!

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I buy that, size of bevel, and of spine has a bigger effect on draw IMHO. I have razors that give little/lots of draw regardless of shave readyness...

Here's something I have noticed over time: the sound of the razor as I strop it is different from shave ready to not shave ready razors. Kind of a sizzle, if that makes sense. Regardless of the grind, I can hear when the razor is getting close to shave ready.:hmmm:

It may be psychosomatic, but that just means my subconscious knows when a razor is about ready, even if I'm not sure yet. Either way it works for me.:shrug:

Mparker, your point depends which photo you are talking about. The one in the top right corner is not indicative of a good razor edge. I intended to use the bottom two as examples (I posted this pic in a different thread and clarified which pic was which then, but forgot to do so this time). The bottom two show the slight misalignment and bending that can occur with use, and it's those small irregularities that I was referring to not the obvious burrs in the top photos.

As for my stropping comment, is it incorrect to say that it is a matter of friction? It seems to me that as the edge is straightened the friction would be increased slightly (not to mention the strop heats up a bit which adds to the draw).

And it's not too far of a stretch to compare knives and chisels to razors edges if they've been honed to the same degree. I've been honing knives longer than honing razors and I can say that it pretty much boils down to the interaction of steel and the abrasive surface, no magical difference because you label one of them a "razor".

I think what matters is that we can all take dull steel, d*$& around with it, and end up with a tool that pops hairs in half while gliding like a feather over skin. So, cheers! I've got some sharpnin' to do.

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Originally Posted by Russel Baldridge

And it's not too far of a stretch to compare knives and chisels to razors edges if they've been honed to the same degree.

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Not a far stretch, yet still a stretch. Can one shave with a chisel, or a knife, with the same results as a properly honed and stropped straight razor?

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Originally Posted by Russel Baldridge

I've been honing knives longer than honing razors and I can say that it pretty much boils down to the interaction of steel and the abrasive surface, no magical difference because you label one of them a "razor".

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No difference in the metal composition or the forging of a straight razor that might affect the honing results?

What I'm asking is, are they really all the same, just different shapes? Or is there something other than shape that makes a straight razor a straight razor?

Scott

I'd have to agree that there is no important difference with the big exception that the bevel angle of a razor is very small and that of a chisel is much bigger. If we ever start using chisels with a scything motion I'll be really worried.

But, if we were to sharpen a chisel with the express purpose of shaving with it (or just cutting a hair), would we do it differently?

I'm much more worried that Scott's or MParker's razors are different than my razors. That would be a much more important issue to me.

I think it makes more sense to focus on the unexplained and the explainable phenomenon, agree on that, and go from there.

For example:

You have the guy that doesn't even believe in strop draw, or,

Back to the corn field example, I think razors shave because the corn field is serrated on the edge by the grit of the stone, but only because it "catches" whiskers a little in the groove, which may explain why "fewer strokes are better". With too many strokes per grit you smooth out the bevel edge too much.

But until you experience the lack of shaving ability from too many strokes on a hone (or agree that the characteristic is true) you might not see the concept or idea at all.

We could debate the presence of striations for a long time before we ever get around to accepting that the effect is more important than whether they exist or not.

Lets say, for the sake of argument, that striations are only visible at 5K magnification and suddenly we "see" all these striations. How do we ever figure out that they are cutting better or worse? Without interviewing the effected whisker after the crime.

Until they invent a hone without grit we have to focus on experiments that study the expected characteristics.

For example, a few years ago I worked with someone that used a sweeping motion while honing and, although he was getting a good edge, got a better shaving edge when he used a simpler more linear stroke. I thought this helped because it aligned the "striations". Now I think it helped because it created "fewer" striations.

I can agree that striations exist on the bevel, I think what we are questioning is the age old assumption that they make a difference and to what extent they make a difference.

And, to the question I have, how can we create a logical experiment that would prove of disprove our theories?

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Originally Posted by AFDavis11

And, to the question I have, how can we create a logical experiment that would prove of disprove our theories?

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High-powered slow-motion magnified video of different razors shaving the same beard at the same level of beard growth. There must also accompany these videos more high-powered slow-motion magnified videos of the stropping and honing of these razors at each grit level and on each strop.

The trouble to do this and sift through the resulting data will relegate the veracity of our theories to the jurisdiction of educated guesses

Any, perhaps, slightly simpler solutions? ;)

Sorry, I'm slightly confused regarding what exact theories we'd like to test. That the depth, amount and orientation of striations on the bevel affect the shaveability of a razor? Or are you referring to Scott's original theories regarding stropping and its effects?

James.

I think we are trying to define a definitive theory of both honing and stropping. We've actually gone quite far. The last time I tried to do this I couldn't even get everyone to buy into the idea that honing was an edge leading motion. :roflmao

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Originally Posted by honedright

Not a far stretch, yet still a stretch. Can one shave with a chisel, or a knife, with the same results as a properly honed and stropped straight razor?

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If it has the same bevel angle and temper, yes.

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Originally Posted by honedright

No difference in the metal composition or the forging of a straight razor that might affect the honing results?

What I'm asking is, are they really all the same, just different shapes? Or is there something other than shape that makes a straight razor a straight razor?

Scott

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The steels that the custom razor makers are using have been in use in the custom knife industry for many years, and are now being adapted to the straight razor market.

In fact, anyone can go out to a junk yard and purchase a rusty old leaf spring, clean it up, grind a 15 to 17 degree angle on the end of it, heat it until it demagnetizes then dunk it in water. The result will be a hardened steel blade that, when honed and stropped properly, will shave hair. (cut the leaf spring down a bit if you are going to try this)

I too have lost track of what is in question. Maybe a short list is in order.:shrug:

Did you measure that or is part of the theory?

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Originally Posted by Howard

Did you measure that or is part of the theory?

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Howard, that's approximate. I derived the 45 degrees from holding the razor canted back at about 45 degrees, and then drawing the razor diagonally down and across the hone while maintaining that canted position. Looking at the very edge of my daily razor under a 10X loupe, I observe what appears to me to be a striated pattern, the striations slanted about 45 degrees downward, from point to heel.

Did I mearsure it? No, but I guesstimate 45 degrees to be about accurate.


Scott

I think that all this thread is proving is that, like Einstien, we are unable to come up with a unified theory of honing and stropping!:hmmm:

Personally, I spent my first few weeks without a strop at all, just honed my edge to 0.5um on lapping films and had at it. I thought that stropping was for manic obsessives and lunatics, since even the Verhoven paper showed no change in edge with stropping, so I thought I was in the clear...

Now I find out that perhaps I am now an obsessive lunatic myself, as after finally getting a nice strop and learning how to use it -- my edges became MUCH nicer, keener, and gave better shaves.

Go figure.:shrug: