Thread: 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


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.

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.

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