Thread: Hones and Edges Under the Microscope

Beginners get very excited by this sort of thing, because they are looking for shortcuts that will take the trial-and-error out of the process. I felt the same way when I first saw the high-res micrographs of razors on my computer. There is no such shortcut. No matter how much you may want these pictures to show you what sharp looks like, they simply do not show this. This may be an apples or oranges thing, but if only apples matter then who cares about oranges?

1) None of this is "new" to the straight razor community. Quite a few of us have 100x or 200+x microscopes and have seen these sorts of images with our own eyes, through our own microscopes, of our own razors. What Tim has done is actually photograph these images and put them all together in one spot for easy comparison, and for that I thank him. The experiences of the old hands already accounts for the information you see in these photographs - these photos do not invalidate or supercede any existing theories or experiences, they simply illuminate why the existing theories and hones work.

2) These are photos of bevels ("oranges"), not edges ("apples"). Pretty bevels do not necessarily correlate with good edges, though it is admittedly difficult to get a good edge with a bad bevel. A good bevel is a necessary condition for a good edge, but it is not a sufficient condition.

3) It is true that there are many aspects of shaving that are subjective, but that does not change the truth of points (1) and (2), no matter how devoutly one might wish.

Those of us with microscopes been able to experiment on the spot with different hones and techniques, so we have been able to actually test for correlations between the pretty pictures and actual shaving ability, and I hate to break it to you but the correlation between the prettiness of the picture and the quality of the shave is not that high. You can use the microscope to check for nicks, for microscopic corrosion, for bad bevels, and for grit size on an unknown hone. But they will not tell you what makes a razor sharp. Good bevels are neccessary, but they are not sufficient. A microscope can help you get the bevel, but trial and error and practice and soaking up the accumulated experience of other shavers is necessary to attain the skills to produce the actual edge.

Well, in retrospect, maybe the world would have better off if Galileo had been burned at the stake!!!

mparker,

What I interpret your saying is that each of us beginners may have to re-invent the wheel for himself and that there is nothing that may be learned by looking at edges or pictures of edges. It may be thus.

However, I had two razors delivered to me yesterday. They were new and sharpened by Mr. Abrams so I could look at and shave with edges honed by an expert's hand. From looking at those edges compared to the ones I have worked on, I believe I have learned something: my edges, so far, have apparently not been taken far enough to create the correct starting bevel. Pictures may not show all, but I think they can be used as a tool to help perfect technique. Thus, I think I have learned something.

Bruce

Originally Posted by rgdominguez

Well, in retrospect, maybe the world would have better off if Galileo had been burned at the stake!!!

I think mparker's point is that the discovery that the earth revolves around the sun and not vice-versa, so that technically the sun doesn't "rise" and "set," didn't change the fact that it gets dark and cooler at night, light and warmer in the morning. The accumulations of human knowledge that preceded Galileo's discovery – about the seasons, about when to reap and sow, etc. – didn't suddenly become less empirical or less true, and certainly not less useful.

My guess is mparker likes nice pictures as much as the next guy and doesn't want Galileo, Zowada, or even you burned at the stake.

Originally Posted by Bruce

mparker,

What I interpret your saying is that each of us beginners may have to re-invent the wheel for himself and that there is nothing that may be learned by looking at edges or pictures of edges. It may be thus.

However, I had two razors delivered to me yesterday. They were new and sharpened by Mr. Abrams so I could look at and shave with edges honed by an expert's hand. From looking at those edges compared to the ones I have worked on, I believe I have learned something: my edges, so far, have apparently not been taken far enough to create the correct starting bevel. Pictures may not show all, but I think they can be used as a tool to help perfect technique. Thus, I think I have learned something.

Bruce

I never said the microscope was worthless, I said you have to be careful about making interpretations and inferences from the microscope that aren't valid due to the limitations of the tool. The first time you see micrographs of the edge suddenly a whole new world of understanding opens up to you, suddenly things seem so obvious, suddenly you can *see* sharp. It takes awhile to realize that things really aren't that obvious, that there is more to it; a microscope shows you the effect but not the cause. I'm sure you're familiar with the story of the south sea cargo cults; it is very easy to get into a similar fallacy if you rely too heavily on the microscope as a tool. The same is actually true for any other honing tool, we commonly see this with the hanging hair test as well, and for the same reason.

The way you used your microscope is a perfectly valid use of the microscope as a honing tool, and this is how I recommend they be used. But you will have poor success if you take what you see of Lynn's edge in the microscope and simply try to replicate that on your own edges. Lynn's edge looks sharp under a microscope because it *is* sharp, it is not sharp because it looks sharp; yet this is precisely the trap you were falling into in your earlier posts. This fallacy is a danger for other tools as well: a razor pops hanging hairs because it is sharp, it is not sharp because it pops hairs, and therefore it is foolish to worry too much about the razor that shaves well yet will not pop hairs, and foolish to be angry at a razor that will pop hairs yet not shave.

Originally Posted by mparker762

Lynn's edge looks sharp under a microscope because it *is* sharp, it is not sharp because it looks sharp...a razor pops hanging hairs because it is sharp, it is not sharp because it pops hairs

OK, point taken, but before you go all Obi-Wan-Kenobi on us I have a question. Does the smoothness of the bevel not at least tell us something about the smoothness of the shave? I understand that it doesn't tell us about sharpness, and I've never totally been clear on the difference between smooth and sharp...I guess what I'm asking is, in terms of razor feel, is edge everything and bevel nothing? I always sort of visualized that sharpness had to do with the edge, and smoothness (at least partly) to do with the bevel. Is that wrong?

Originally Posted by mparker762

I believe you are mistaken or at least confused on this point. For a given grit, chrome oxide and diamond produce similarly sharp edges, but the chrome oxide will be more comfortable to shave with. However, diamond is available in much finer grits that will get you to a sharper edge.

Regarding empirical evidence: If a member notices that chrome oxide shaves smoother and more comfortably than equivalent grit diamond, that *is* empirical evidence that chrome oxide edges shave smoother than equivalent diamond edges. These photos, while interesting, are *not* empirical evidence of any statement about shaving quality; they are empirical evidence of bevel smoothness, scratch density, etc. It may not be obvious to the newer guys, but these pictures don't actually tell you much about how sharp the edges actually are or how well they shave, they just tell you how smooth the bevel is, and something about how smooth the fin is. But they don't actually tell you how thick the cutting edge really is, or how it feels on your face. So it's easy to invest more meaning into these photos than is actually there. There is a common mistake among newbies, we get a lot of posts along the lines of "what does a sharp edge look like under a microscope" and there's no answer for this, because while sharp edges tend to look a certain way, dull edges can also look that way.

Mparker, you are absolutely right. Thant you for taking the time to correct me. The way that an edge shaves is the real "empirical" evidence, not the way that the bevel looks under the microscope. Additionally the scratch pattern in the bevel does not necessarily correlate with the quality of the edge or the shave that the edge facilitates. I guess what I meant to say was that I am interested in seeing what the surface of the various honing media look like under the microscope and their apparent effects on the bevel of the razor (which might or might not have a positive or negative effect on the edge). I have been following your posts and agree with your points.

Originally Posted by dylandog

OK, point taken, but before you go all Obi-Wan-Kenobi on us I have a question. Does the smoothness of the bevel not at least tell us something about the smoothness of the shave? I understand that it doesn't tell us about sharpness, and I've never totally been clear on the difference between smooth and sharp...I guess what I'm asking is, in terms of razor feel, is edge everything and bevel nothing? I always sort of visualized that sharpness had to do with the edge, and smoothness (at least partly) to do with the bevel. Is that wrong?

The bevel smoothness doesn't tell you as much as you'd like it to, which is unfortunate because the bevel is easy to see and the edge isn't. Remember the story about the woman searching for her keys under the streetlamp even though she dropped them under her car - she was looking under the streetlight because "that's where the light is". The bevel is similarly distracting; it's big and easy to see, and it's really a pity we don't shave with it.

You can see from those photos that the translucent arkansas stone produces an extremely smooth bevel. Yet the shave from a translucent arkansas stone is not as smooth nor as sharp as the shave from the 15k Shapton (at least not without some solid stropping of the arkansas edge). My 15k Shapton can produce an edge that is very nearly as smooth-shaving and sharp as the chrome oxide can produce, yet you would not guess that looking at these photos (admittedly the razor in the 15k Shapton photos here is overhoned, but still you get the point). I don't have a 240x USB scope anymore, but these photos are consistent with what I remember from those days, and are consistent with what I saw in my 100x when I honed with these stones last night.

The bevel does have a part to play in our perception of sharpness, but it is secondary to the cutting edge. There is a point when the edge has started cutting into the hair, where the hair is splitting apart and pressing against each side of the bevel. At that point, there is a surprising amount of friction between the whisker and the bevel. Have you ever noticed that leaving the lather on one side of the blade after you flip it to go another direction seems to improve the shave and reduce the tug? Commercial blades are coated with a solid lubricating layer to reduce this friction, and it is one reason that commercial blades feel sharper than straight razors and seem to stay sharper longer without stropping (the other two reasons are the commercial blades are honed at a steeper angle so the edge lasts longer, and the commercial blades are coated with specially hard coatings like platinum which also helps them last longer). However, if the edge isn't sharp enough to cut into the hair then the frictive character of the bevel doesn't come into play.

What I do not know is whether smoother or rougher bevels causes less friction and tugging. I can see the argument either way, but have not been able to resolve this question satisfactorily so far. However, I have only been investigating this specific issue for a few weeks.

I think one problem this discussion is pointing out is that we don't really know WHAT makes an edge shave well, exactly. Some people feel an edge with microserrations cuts better; some guys insist that smoother is better.

It's quite possible that the "best" edge depends on the unique makeup and texture of your particular beard--I think I lean toward this way of thinking.

Just because a hone produces a more polished bevel, and, we assume, a finer, more polished cutting edge, doesn't necessarily mean that a polished edge is more desireable. Obviously, some level of polish is good, or we'd all be honing on bricks. But the question remains: microserrations or no microserrations?

Great thread, though.

Josh

Originally Posted by JoshEarl

It's quite possible that the "best" edge depends on the unique makeup and texture of your particular beard--I think I lean toward this way of thinking.

If you go through the archives you will discover that for a period of many months I felt the same way. I am less certain of this now; though nowadays I find that I am less certain of a great many things.

Certainly if the frictive character of the bevel turns out to be significant then we might conceive that for certain types of beards a sharper edge is better, but for others a lower-friction bevel would be better, and absent the sort of coatings available to the commercial guys these two characteristics may be at odds.