Reason behind pyramid honing and other musings

So while I was doing complicated engineering math in another thread, I had an epiphany that I want some comments on. I have to give some credit to Jende Industries for jump starting my brain, Lynn for his Norton Pyramid scheme, and gssixgun for unknowingly providing the first step to my evidence, in said thread. Here's the thread, it will probably help. http://straightrazorpalace.com/basic...too-sharp.html
See also Jende Industries argument, I think he put it quite well, save the last part about over polishing which I disagree with (see the aforementioned thread) Sharpening Epiphany « Jende Industries Blog

Please read through this, even though it may be boring, I am really interested in hearing what people think, and definitely interested in hearing counter arguments or support. I'm not saying I'm right, I'm just very very curious about this.

So here's my idea: Think for instance about something vibrating. (Musicians will get this maybe better than other people) When you have frequencies with periods that are multiples of each other (known as harmonics) the two combine to make a beautiful noise or a stronger signal. Or, when you have something of the same frequency, it can cause resonance (the reason some building fall in an earthquake and some don't, it causes the screeching feedback in microphones when they are two close to a speaker, its the reason glass shatters when singers hit a certain note). These are called response frequencies, and almost everything has natural response frequencies. That is a known fact.

Now is where I need help.

First Proposition. I read everywhere about people having different results with different hones and different razors- the blade won't take an edge on say a Norton 8k, but loves the DMT 8k. Here's my first proposal. The tiny little cutting grains occur in something of a regular pattern at the molecular level, causing scratches in rows, with peaks and valleys. What if I razor were to hone better where the steel's material properties matched the hone's material properties in terms of complimenting frequencies? Like, the type of cutting particle (garnet, CrO crystals, pieces of diamond) matches the molecular structure of the steel somehow. This is a crap shoot and I have NO evidence other than musing, but I feel it may have some warrant.

Second Proposition. The reason pyramid honing works is because two grits will create just the right (or close enough) scratch frequencies to cancel each other in the Fourier series that results from their combination to make a straight edge. (English: the grits create scratches that cancel each other out very well) So with the Norton's, 4k and 8k are maybe in harmony- as the 4k makes harsh gouges and sharpens, the 8k cancels the peaks, bringing them down to the valleys, thus smoothing it. So the 4k sharpens, and the 8k smooths. Each time you do a step in the pyramid, you sharpen a little, polish smooth, sharpen more, polish more. You taper the 4k, because as Glen says, the bevel approaches a perfect point and all it needs is polishing.

Third Proposition. The reason people find combinations that work for them is because they by trial and error discover hones with these relative scratch frequencies. I keep reading about someone who goes through some seemingly random progression, and if someone suggest a different stone they say they've tried, it didn't work, or they try it, it doesn't work, etc.

Fourth Proposition. The variance in natural stones is of course to be expected. But I think the reason that some natural stones really shine while others are seemingly duds is because of my frequency argument. If I have a nice progression set up, and I need a polisher, I'd need one that fits. Lets say I try a coticule. I find the shave sucks. Off an Escher thought, it feels like a magic blade, sharper than a scorned woman's tongue, smoother than a baby's smelly end, and its as comfortable as Southern. (southern comfort... come on...). I try a chinese 12k for ****s and giggles, the shave is not as good. Maybe its because the Escher fits my hone progression. But to go even further, lets say I try three Eschers. Only one of them is the God-Stone. The other two may as well be 80 grit sandpaper. Does this mean they are inferior. I sell one to Joe for ten bucks. He thinks I'm an idiot, he loves the shaves he gets off of it. Maybe the natural variation doesn't cause shiners and duds, maybe the natural variation means some fit, some don't.

Fifth Proposition. Human stones are more consistent than natural stones because they were engineered that way. If you buy a set of Shaptons, they will work. If you buy a 4k/8k, and pyramid it, it will work. They were engineered with tolerances, to have them be consistent. The natural stones were completely random, so their tolerance are wider. Hence "perfect" stones and "duds". That goes without say. But then why is there no standard? Why is DMT 325, 600, 1200, 8000, where Norton is 220, 1k, 4k, 8k? Maybe its because the engineers found those grits just seemed to get the job done. They worked well together.

Now, I'm no honemeister, nor do I have any stones or anything. All this is based off of what I've read people say, and my knowledge of engineering. I am willing to bet that a good enough honemeister will have worked out the tricks that make things work with anything, but I am willing to bet that a lot of things that "just work", "just work" because at the microscopic level its like puzzle pieces fitting together.
I guess my last statement is it seems if there is at least some truth to what I proposed, there is no perfect hone, simply the "perfect" combination of hones and a honer/honemeister (as experience differentiates) that knows how to make them work. Like an orchestra and a conductor.

wow it will take at least 35 minutes to read this . would you please put up shorter version of it?
thank you

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Originally Posted by khaos

I guess my last statement is it seems if there is at least some truth to what I proposed, there is no perfect hone, simply the "perfect" combination of hones and a honer/honemeister (as experience differentiates) that knows how to make them work. Like an orchestra and a conductor.

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I had to read all the way through that :gaah:
To find you came to the same conclusion that I did some time back, that razors have different combinations to get them sharp and smooth....

I do like the way you explained it though...

ok
3 rd one
it is because not everyone sharpness blade same. there is a lot reasons could be factor's. pressure, strokes etc etc.
about 4rth
Sorry
i am not agree with You.
Natural hones will act differentley but that doesn't mean example 1 escher will act as a 30000 grit and next one will be 2000 grit,there is not such a gap amoung them.
could act example 20000 next will be 18000 etc . not so much caps.
hope this helps

Well I was exaggerating on the Eschers. What I was meaning to say was more that one Escher may suit your style/get up better than another because of the variations. I realise that the quality stones like Escher and Belgians and Japanese's are quite consistent.

and Glen... I believe I credited you for backing up my musings/inspiring my thoughts with your posts earlier... I was not so much coming to conclusions as proposing reasons for them. So I did not come to conclusions. I sought to explain your lol.

The following is my entirely unfounded illogical opinionionated musings in contradiction of the original post. It is not an indictment or criticism of the author.

Sorry, but I don't buy most of this. First, the synthetic and diamond hones are/were developed for tools other than razors. The only exception would be the barber hones, which tend to be only in the higher grits.

Oops. Let's go in order.

Prop 1. The scale of the grits do not correspond with any sense of molecular level. I don't know squat about metallurgy, but I would assume that the molecular patterning of the steel is at a much smaller scale than any level of periodicity of the hones. Even if that periodicity is due to multiples of that patterning, I doubt such uniform periodicity would exist at such a perfect level required for what you are proposing. That would require perfect uniformity in both the steel and the hone. If you look at a hone under a microscope, you ain't gonna see much periodicity.

Prop 2. First, you are not making a straight edge. You are merely making an edge that has less extreme high and low points. Consider the reason that a fine DMT plate cannot be used to lap a hone. Normally, when a DMT plate laps a hone, the high points of the diamonds cut into the high points of the hone. In a newer DMT, you often have a few diamonds that stick up higher than the rest and that shows up as scratches in the hone. Fairly quickly that diamond is worn away because all of the stress is on it, so that eventually the peaks of nearly all the diamonds are of uniform height and stressed uniformly. Then the diamonds, relatively speaking, cut a uniformly smooth field across the hone. That is, you are reducing the extremes between the high and low points. However, if you use a fine grit DMT, the highs of the hone extend so far into the lows of the DMT that the hone grit undercuts the diamonds and releases them from the nickel plate.

What does this have to do with honing? :gaah: Consider the high and low points of the hone and the blade. When you hone with a low grit hone (4k), the high points of the hone can cut deeper "trenches," or low points, into the blade, resulting in serrations consisting of peaks and valleys in the blade. When you then hone with a higher grit (8k), that grit cannot reach the bottoms of the trenches of the blade. The 8k grit can only cut the tops of the peaks of the blade, but by doing so, those peaks are shortened. This allows the next round of 4k honing to be able to cut deeper trenches, because all of the peaks on the blade have been shortened by the 8k. The reason that the number of strokes with the 4k is diminished is to reduce the number of deeper trenches and to, overall, end up with serrations that have shallow trenches with peaks that have been relatively flattened by the last round with the 8k.

Prop 3. I believe that pyramid honing can be done with any combination of two adjacent grit hones. It just seems to be most productive in the middle grit range. The "random progressions" you describe are merely the result of so many people starting out with so many different hones.

Prop 4. The reason that some natural stones work better than others has nothing to do with which hones with whatever presumed periodicity preceded it in the progression. (Go ahead, say it 5 times.) Some natural hones work better than others, period. They have different cutting characteristics. They may or not release grit, which may or may not break down to form finer grit. They may or may not be homogenous. I don't believe the that progression that preceded the natural stone has any impact on the performance of that stone.

Prop 5. I'm not sure I can agree that synthetic stones are engineered to be more consistent. Sure, they sort the grit to be a fairly, not perfectly, uniform size, but then they mix it with the binder, form a sludge, and pour it into molds and hope for the best. If you look under a scope at some natural hones, you will see that Nature, at least occasionally, came up with some pretty good sludge products itself. At least, I've paid a lot of money for some of that stuff! Anyway, randomness still occurs with the formation of the synthetic hones too. Take a look at the bottom of this post for photos of my two Norton 4k hones. The first is made in Mexico and the second in the US. Tell me how consistent you think they are!

Regarding the grits of the DMTs and the Nortons. I have no idea why those particular grits are used. Certainly in sanding and in honing it has been found that a progression of finer grits is required and the steps between cannot be too great without loss of effectiveness. A higher number of grits (say, 220, 230, 240,..., 7900, 8000) might do a better job but it's not practical. Engineering is about effeciency as well as effectiveness.

Finally, I thought what you proposed was interesting, and I appreciate that you proposed it. I work in science, where every thing should be challenged, so I have a habit of doing that, whether I know what I'm talking about or not. Thus, the above!

:jedi:

My theory is similar to Utopian's. But I'm no expert.

I am not an expert either but I know an expert. His name is Lynn Abrams and he has found after honing thousands of razors that the pyramid method works consistently and with repeatability. I don't have much formal education and most of this scientific theory quite frankly is over my head. I enjoy reading it though and trying to understand it.

Fortunately for me I needn't understand why it works anymore than I need understand why my computer powers up when I press the switch. I learned the pyramid method by studying Lynn's DVD and reading SRP. I had help from individual members and got to the point where I can get a beat up ebay special with an edge that looks like a hacksaw blade shave ready with the pyramid method.

So I am very glad you brought it up and I will continue to follow the thread but just as when I erected steel in my younger days I didn't understand the engineering and I didn't have to in order to hang that girder 200 feet in the air. :)

Utopian. Great points. Thanks. I would like to rebut some though.
(First a blanket statement. When I refer to frequency I realise it is not a perfect frequency, but in reality, everything can be expressed with a periodic fourier series, even a straight line. So in order to actually prove this not just hypothetically, I would need to do an absurd 2d Fourier series to describe the hones cross sections along its length. Instead, I just used the word frequency a little too loosely)
Prop1. I had meant not that grits mean somethign molecular, but maybe the way the steel was bonded would perhaps respond better to the round garnets of BBW/coticule than the angular diamonds of a DMT, or vice versa. Or potentially an underlying frequency in the hone.
Prop 2. Yes, you are correct, the edge is still not straight. I was overstating everything to make it more explicable. Besides that I think we are in agreement, you just said it more precisely. This is probably due to the fact that you are more expereinced than me and I was just thinking this through.
Prop 3. I acknowledge that some of the random hones has to do with people owning random hones, but I've seen quite a few experienced honers give me a progression thats like, start on the DMT, move to the Norton, move to the Chinese, finish on a Shapton. Or something equally diverse.
Prop 4. Point taken. Sorry, I wasn't trying to say that all natural hones are the same (within type). I was trying to say maybe some people like certain stones because they fit their progression. I have never taken say, 8 edges off the Norton 8k and tested 8 finishers, then taken 8 edges off the Shapton 8k and tested the same finishers, so I can't prove anything. Hence my error. Thanks.
Prop 5. I concede that we are not perfect and don't make consistent hones. However, they were still engineered to be consistent, even if budget cuts caused otherwise. I don't know how many times when I asked, what should I buy? The answer was Norton- consistent and a lot of info, so the hone won't be the problem and there will be a lot of people to tell you how to fix your technique. However, inclusions, striations, etc. may or may not impact natural stones. For instance, slate is useless as a hone, unless it contains Mica, at which point it apparently cuts very well.

Please counter rebut! I love learning, especially Socratically.

Khaos,

Thanks for the plug to my blog! I read, and understand what you are saying. Let me just start by saying that I'm glad I'm not the only one who like to analyze sharpening! No matter what anyone says here, keep thinking, and even if some ideas don't fly, you at least challenged us to think and talk about sharpening.:rock:

Part of me was thinking that you are over analyzing sharpening a little. It will never fit into a formula - and that's the beauty of it. The idea that a sharpening medium could be tailored to compliment the exact metallurgic make up of a tool is far beyond cost effective - as amazing as it would be if it were possible - because, again of all the variables, too many to get into. Variations of personal preferences alone is enough to throw things off. If you Talk to Howard, there is also flex and the effect of atmospheric conditions (and the spin of the earth :D) One could even argue that the microbes, sediments, or metals suspended in the water come into play. (We don't drink tap water in Taiwan, BTW).

However, for prop.1, I think if you were using a tumbler or ultrasonic cleaner, you could be on to something. The right material at the right frequency could result in faster results and/or better finishes (polishes) on different types of steels (or you could ruin your mom's best cookware). If the frequency is too high or low it would cause turbulence that cancels out the effectiveness of the vibrations. In music its called a wolf tone (I have a degree in music BTW). If you divide the frequencies in half, you get the same pitch, just at a higher or lower octave, which intensifies the number of overtones, or vibrations that are are sync. This makes sense - but not for sharpening on a stone, I'm afraid.

Prop 2. I think that is along the lines of what I was thinking. Your second to last stone is really the one that establishes the final grooves in the edge, while the last one smooths over the peaks. Otherwise, the final stone will make new peaks and valleys.
But your prefect point must be established before 4K (I would even venture to say before 3K), otherwise it will take an awful long time to get one.

Prop. 3. Price and availability are big factors when purchasing stones. As people get better at sharpening and are ready to "step up", they buy what they can afford. Why spend money on 2 of the same grit stones? Some people can sleep at night mixing and matching their equipment. Others like consistency. Shapton, King and Norton, to name but a few, offer this consistency even though their consistency is not necessarily consistent with other brands. Only when people get serious (like us) do they get picky about the consistencies and the results their stones get. Also, people go with what's popular or what is suggested to them by pros. With no disrespect to Lynn, but if Lynn said that he uses the bottom of a greasy 8lb cast iron skillet loaded with CrO2 for a strop, wouldn't you do it, or at least think about doing it?:bow

Prop 4. Natural stones will have variations and anomalies. Their grading system is not as exact as synthetic stones. In general, I would have to say that a good sharpener will get results on any set up (provided it is reasonable - i.e. not trying to jump from #320 to 8K) although he or she may prefer either naturals or synthetics over the other. It comes down to understanding sharpening, and how the stones work and respond in relation to what you are trying to achieve. That can take time to learn, even on synthetics.

Prop 5. I think this is a question of abrasive material. It is perfectly acceptable to go from 1K to 6K on a kitchen knife (which is what I do), but just like prop 1, halving the size of the abrasive is mathematically more sound:), but may be unnecessary for actual cutting action. I'm not sure how to word what I want to say here, but when doubling the grit, it may not be the "best" or most economical solution. I think after a 1k, if you can use a 3k or 2k, which one is then more "correct"? If you use the 3k, it may be a waste to use the 2k instead. DMT #1200 jumps to 8k, for example. (If someone knows what I am trying to say here, and can say it better, please do)

And lastly,

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Now, I'm no honemeister, nor do I have any stones or anything.

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Its okay to admit that you don't have the stones to become a honemister.:rofl2::roflmao:rofl2:

Great post! Keep thinking!

The reason behind pyramid honing – it works and gives consistent results.

My unscientific view

Charlie

Here is where some of you guys get way of track when it comes to honing....

I love reading some of the explanations taken to the nth degree by many of our Engineer / Mathematician types on the forum....

Although they are great reading and maybe some of you have some sound theories out there to explain what is going on when we hone... here is the bottom line unfortunatly....

Honing a straight razor is way more of an art then it is a science, if it could be quantified into a science we would have honing machines.....
But sooner or later it is the Honemiester's touch and experience that brings the best edge to the "sink"....

I realise this. I think I've said several times that I know things just work sometimes, and that experience is much better than theory. I'm just curious as to why. It's my fatal character flaw. I don't like just accepting. I will if I have to, but its nice to try and found out why. (Hence I'm an engineer instead of an English major... since an early age I've been reverse engineering everything that broke in the house- lawnmower, hairdryer, smoke alarm, blender, kitchen timer- and lately figuring out how to fix it when I'm done tinkering.) Thanks for all the responses guys.

I actually liked the wave theory, that was a cool way of thinking about it.. I liked the different scratches theory too...
The way you guys are thinking this through is kinda neat, it helps to visualize what might be going on at the edge level...

And if it helps anyone to get a great shave then I am all for it...

I think the wave/scratch theory for smoothness/sharpness is the soundest. I also still think that pyramid honing can be explained by that to some degree. The "harmony" arguments I guess were just ideas that didn't hold up so well. But I definately learned and thats the point.

I agree it's an art. I'll not comment on the rest. I think honing is quite a bit simpler than this. In fact, I think its much easier than this, in concept and practice.

But I'm for people thinking it's really, really, hard and complicated. And I agree that Lynn is a master at honing. :)

I see it more as sculpting steel with flat stones.

I think too many people think that when something is difficult that it must subsequently be complicated.

If you only knew how complicated even the simplest things were lol... The main thing I learned in engineering is everything is complicated. I interned at BorgWarner for a while last year (til the car industry in America collapsed) and they are the world leader in automotive parts and engine testing, they invented automatic transmissions, silent chains, VCT etc. Anyway. They're really famous for accoustics. You know that clunk your door makes when you close it? Do you know how much testing went into it? The clunk your door makes was engineered to sound exactly like it does through testing, surveying people on ear-pleasing clunk sounds, etc. The shape of a shift knob is another example. The way I got the underlyign frequency was a combination of my differential equations class (Fourier series and resonances) and testing at BorgWarner that I can't really describe but basically they found that if certain parts of the car vibrate at specific frequencies it can hinder/help other parts, so each part is designed to harmonize with the other parts. This is what lead to silent chain, amongst other things. EVERYTHING is complicated when you get down to the molecular level.

Then I will humbly bow to your education on the subject . . .

good luck with your honing! :)

I barely have any education. Just saying even the simple things in life are massively complicated.... *sigh*

Yes, I know the clunk the door makes. I also know that for the last 8 years I've been trying to convince my wife that she does not need to slam the door on my Honda Prelude, which was engineered to produce a perfectly fine resonant satisfying clunk with minimal exertion of force. I cringe every time she slams that door.

On the other hand, this is one of the few complaints I have about her so I keep my mouth shut (almost:fim:) every time that door crashes shut.

LOL. I can certainly say the same of my girlfriend. Not the car door thing. The keeping my mouth shut because the good far outweighs the bad.

Shapton glass for American market were engineered for A2, so there is work being done in that regard. I hear they are doing more. Norton consistency? who'd a thunk it.

I too like thinking about sharpening on the microcrystalline submicron scale; but it never seems to help me hone better. It's just an interesting distraction when you're crazy about stone and steel.

I have never tried pyramid honing and likely never will. I don't understand its purpose. An edge that has been re-finished several times(more than just touching up) feels to me sharper and sharper. removing more and more residual coarse scratches makes the edge increasingly more continious.

"teeth", coarse scratches and such to my mind are micro stress risers that can only lead to larger chips.

I can dig the resonance idea with the pyramids. I'll go you one further: what grit sizes correspond to what musical notes? For example (i'm making up number because I don't know) a 4k grit has particles that are 10 micron across, which is the width of a sound wave vibrating at 440 cycles per second, or A in the staff. Now if you were to hone with a series of Tambura players droning on A around you, would the sound frequencies interfere with or cooperate with your 4k hone? The possibilities are endless!

I'm pretty certain, in theory, you could shave with a harmonic generated off a tuning fork and skip the stone/razor combo all together.

The emphasis on "in theory" is probably very important here . . . :)

While I sense a certain sense of sarcasm, if you were to try and hone a razor with it's response frequency it would shatter.... this is why singers break glasses with their voices....

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Originally Posted by AFDavis11

I'm pretty certain, in theory, you could shave with a harmonic generated off a tuning fork and skip the stone/razor combo all together.

The emphasis on "in theory" is probably very important here . . . :)

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I'm no history buff, but I believe this is one contributing factor to the Axis forces losing WWII. They got caught up on the concept of a death ray using radio and sound waves. Was just too impractical, or, not as effective as, well, you know.

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if you were to try and hone a razor with it's response frequency it would shatter.... this is why singers break glasses with their voices....

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Maybe, but the decibels required would strain even the most powerful amplification system. Not to mention the stiffness of the steel and/or hone would lend to a very high resonance frequency. I wasn't suggesting using the response (resonance?) frequencies, but matching the distance between particles on the hone with the peaks and troughs of sound waves to get a coupling effect. That, and I was being geeky/sarcastic.

:ziplip:

Of course it would take far too many decibels. But if you had enough to sharpen steel (alter its properties) you would have enough to cause resonance (alter its properties). And I know what you mean. The issue is not the frequency of cutting pieces, but the frequency of its cutting pattern, which will almost certainly not correspond to a natural wave.