Thread: A Unified Theory of Honing and Stropping?

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. 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.

Originally Posted by Russel Baldridge

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

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?

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.

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.

Originally Posted by honedright

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

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.

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