A CONJUNCTURE AND, IF TRUE, IMPLICATIONS

[vgeorge]

BACKGROUND:

1. 
   [li]Bart’s hard soap experiment [/li]
   [li]Emmanual’s circular honing and turpentine + bee-wax honing[/li]
   [li]Denny’s wax trick and plaintive claims about jeans/linen rubs[/li]

All these sound a bit like teenage games of certain type, but I think there might be a common scientific/technical link that might explain some things, and even give a plausible explanation for what people have reported. Hear me out.

CAVEAT:

I am an empiricist. A gram/ounce of evidence is worth a kilogram/ton of theory. At this time, the following unfortunately is pure conjuncture from me. Some people here might know for sure whether some elements below are indeed true or false. Please speak up. Although a novice, you are not going to hurt my feelings.

EXHIBIT # 1:

You must have seen this many times. Bart has a graphic that demonstrates the characteristics of a razor’s edge. It shows not only a serrated/saw-toothed edge, but also gouges leading from the edge. Both the serration and the gouges are ostensibly from the abrasion against (relatively) boulder like garnets. It makes a lot of sense.

I cannot find Bart’s picture right now. So …, I am going to show you a photograph of a crude simulated model. Since the thicknesses are at the micron level, I am going to use aluminum foil.
Here is the Bart’s graphic ‘modeled’ in aluminum foil:

EXHIBIT # 2:

If gouging is possible at the edge, serration and teeth are possible as well. Remember in Bart’s graphic, and in most of our own conceptualization, the edge is in one plane. We also imagine, I do, the serration teeth following along the ‘straight edge.’

There is no reason always for this to be so for the teeth (to be in one plane).

The teeth of the serration can point in many directions depending only on the physics of the preceding impact with the random abrasive element. I would think that, therefore, in all likelihood, the teeth would be pointing helter- skelter. This is what I ‘model’ in this photograph, granted with a lot of creative license:

IMPLICATIONS

Though there are other candidates for causing HHT-violins, an edge with three-dimensional serrated teeth will certainly do that. Why? For the same reason the hair will play violin against any serrated foil. It does not have the strength to cut. Chance of the hair finding a sharp edge is small indeed from the above picture. (On the other end of the spectrum, the HHT will only violin – if you can call it that - with your bread-knife too, right? It has strength, but no keenness.)

I am assuming that edge serration that follows the kind of techniques we use most likely happens with unacceptable localized thinning at the edge. This assumption may not be entirely correct. I know people constantly assert that you cannot over hone with a coticule. I do not know if that is true or not. If the gouges of the kind that Bart drew are possible, and I think they are, you cannot claim coticule will not over hone.

Irrespective of all that, there should be no argument that three-dimensional serration will wreak havoc on your facial skin.

HANDLING THREE-DIMENSIONAL SERRATION AND EVIDENCE SO FAR

1. 
   [li] I think circular/elliptical honing will encourage the teeth, if formed, to point in one direction. It also will knock off some of them. Recall the success of Emmanual’s circular - OK, OK, elliptical - honing. [/li]
   
   [li]Hard soap, wax, etc. might actually do something beneficial for both surfaces. A lot of the hone’s surface may become masked, and only part of the tallest abrasive elements may become exposed. That will be equivalent to reduction in BOTH particle size and density. On the bevel, gouges would get filled up and only protruding metal will be more easily available for abrasion. The improvements reported with soap and wax by several members have to have some association with reduced damage to the edge, irrespective of whether the causal factors are as described. [/li]
   
   [li]Stropping on not-so-taut soft surfaces would also encourage alignment of teeth as well as create an action similar to shaking of milk teeth, which likely leads to removal of the weak teeth in the serration. Recall Denny’s jeans/linen success. [/li]
   
   [li]I think, the above three, taken together can (1) minimize the formation of serrated teeth (2) align them straight along the edge, and (3) get rid of some or lot of them. For most of us that may be enough. The ideal, of course, would be the edge without any of those serrations. [/li]
   
   [li]I would think a thin bevel would reduce the chance for these pesky teeth to be formed because there is less thin material to start to form the serrated edge. Slight increase in the honing angle (tape!) might help here. Failing that, we will have to find the equivalent of Denny’s Dovo lady’s wet horn. [/li]

 

[Guest]

I nominate this post for the "most innovative and inspiring post of the month" award. To me, it looks like a very plausible explanation, for which many thanks!

Best regards,
Robin

 

[Bart]

Vgeorge,

you've made a nice encompassing theory on what I like to call sub-micron edge geometrics.

The problem is this: while your hypothesis that form the building block of your theory are deducted from good logic, several of them are invalidated by more profound scientific research. I've been at your point, made the same logical assumptions and came to more of less similar conclusion. I made drawings, spend hours and hours working on 3D computer simulations, but it was all nullified the knowledge that steel at the sub-micron level behaves very differently than what we can observe and mimic on large scale models.
Care to see one of my 3D models?

Unfortunately this drawing is wrong.

And here's a SEM picture, taken from John D. Verhoeven's "Knife sharpening experiments", that shows us why it is wrong.

This picture is taken at 3000X magnification. At left, we see the very tip of the edge. Verhoeven used his these pictures to measure the radius of the intersection line between both bevels (which is below 0.5 micron for on a razor's edge). At the right we see shots of both bevel sides. Note that a SEM image has sufficient depth of view to show grooves and protrusions if there were any. So. Why don't these SEM images resemble your and my models then? Where are The Grooves that form The Serrations? It took me days to accept (after all the work I'd done), but the simple truth is there aren't any. What we do see, are small bur-like structures, and I do believe they can be both reduced, and "aligned" by stropping. But we don't see teeth or serrations that are supposed to be misaligned.

Further reading (google: "Carbon steel surface conditioning", "Steel Plastic Deformation", "Steel Plastic Flow"), in various study, taught me that the edge takes shape no only by abrasive formations of grooves. There are effects similar to that of cold rolling at play as well, likely at various rates depending on the steel of the razor (Stainless responding more ductile than other carbon steels). As a result, any theory that starts with an abrasion-only model is doomed.

Some further thoughts:

HHT "violin":
The outer shaft of a hair is formed by overlapping shingles. The hair is always severed in between those shingles. The violin sound is caused by the edge catching in between the scales, but not being keen enough for further penetration, the hair plucks the very edge, like a guitar string. That causes a very faint ringing sound, and one can also feel it in the fingers. It has nothing to do with serrations.

Overhoning:
I don't know why it this seems impossible to accept for some. Everyone known to have extended expertise with Coticules, (Gary, Paul, Ralfy, myself), have stated time and time again, that they've never encountered anything that would remotely fit the notion of overhoning. I know. That's an authoritative argument. But I don't know why we should discuss something no one ever observed, and no one was ever able to come up with a recipe to produce such a result. Quite frankly, I haven't yet been able to "overhone" on any of the hones I posses, and I've done many laps on all of them.
The only medium on which I have ever had negative experiences with doing more laps than strictly needed, were pasted strops.

Kind regards,
Bart.

 

[tat2Ralfy]

Fantastic stuff gentlemen :thumbup:

I am far from scientific enough to add anything, apart from that the old fashioned idea of "Fins" at the razors very edge, has as far as I understand been proved to be misinformed, and also in my limited understanding, the action of stropping, serves to smooth the very edge, due to the way steel behaves when it is so thin, "like a plastic"

Is this layman correct?

Regards
Ralfson (Dr)

 

[Guest]

Vgeorge.
I think that your post has reasonable positions.I would like to procced with my posts concerning
1) Elliptical motions and 2)overhoning.
The ellitical motions honing it isnt my discoverd procedure,but is the product of many generations's of experience.Lapping any surface is considered the most friendly motions is the
circulars. Of which involves that elliptical honing will encourage the teeth.It is something that may prove by microscopy only.And finally why should be follow this process ,if for years
i have daily excelent,according to my humble opignion,shaves.
Now ,overhoning .First we have to agree what is overhoning.If overhoning is the steel wasting,
yes exists.But if is the microbar creation ,i answer emphatically.No does not exists.
Friendly
Emmanuel