How I use nano-grit compounds & my thought about them

[LessLemming]

Say that you use CrOx after a 10K stone.
CrOx is ~0.5µ which translates to about 30K grit.
And since CrOx cuts rather slow, you certainly don’t get a true 30K grit edge, what you get is a polished 10K edge. Which for most people is both a bit sharper & a bit smoother.
But you haven’t taken out the 10K scratches, you have as said polished them

Interesting thought. But have you read the paper on sharpening publicized by J.D. Verhoeven?
He showed what miracles a Chromium Oxide or Diamond loaded strop can do.
They actually are extremely fast, given their fineness.

Now you might be right with the scratch pattern, but that´s not what makes a razor shave well.
It is the smoothness of the edge and lack of burr or detorriation.

Since most mediums we apply polishing compounds to have a certain give to them,
the compounds reach the very edge in a micro-level arc.
This arc produces a micro-level appleseed form of the edge.
I don´t talk about real rounding of the bevel, I´m talking about the very last 1/2 or even 1/20µm of the edge.
Most of the burr, detorriation and all the freyed edges of microchips simply cannot hold onto this arc,
and will fall off/be removed, leaving the edge very keen and smooth.

In fact that´s what I think is the difference of honing and stropping on compunds
and the reason why compounds in fact are quick and effective.
So effective that I actually can produce nice edges of a 3.000 or 6.000 finish,
with less than 10-20 strokes on a 1µm diamond strop on felt

It´s not a sharpening action

 

[mvh]

To be fair, Verhoeven used a buffer which speeds up the process big time. To get the same results by hand, you would need to spend ages on the strop.

 

[LessLemming]

That´s true and has indeed slipped my mind.

But the point was, that a razor sharpened on a 10k stone takes on the edge of the polishing compound,
not that of the 10k. For sake of comparison I will even go further and say that a Blade finished on an 8.000 JIS stone like the Naniwa Super,
will be indistinguishable from a Shapton 30.000 finished blade, after both have been stropped on a diamond or Cr2O3 strop.

Once a blade is finished, say on a 8.000 JIS stone (some would even agree that this is true for any blade with a sufficiently set bevel!)
it doesn´t take much to bring the edge to its full potential. So the jump in grits gets decreasingly important with increasing grit rating of the stone.
The jump from 4.000 to 8.000 is bigger than that from 16.000 to 30.000 (speaking Shapton grits here!),
even though both the Mesh rating as well as the micron rating are equidistant.
It may take 40 to 50 strokes to get the edge from the 4.000 to the 8.000 level,
but only 5-10 strokes from the GS 16k to the GS 30k.
That was where I was going at.

I believe there is a reason for that.
The theory is that sharpening an edge (generally spoken) consists of two different actions.
One is an abrasive action. Metal is scratched and taken off.
The second one is a flattening action, steel at very small scales will deform plastically.
Similar (not identical, though) to a alum foil. You can easily bend it any way you want.
That´s because it has a thickness of only several µm. Try doing this with a 5mm bar of Aluminium.
Sometimes there is even a chemical action, besides the physical abrasion.
This is important for polishing glass (rare earth polishing compounds are used for polishing glass),
but not so much for steel.

The theory says that with increasing fineness the abrasive action gets less important,
and the action becomes more and more a flattening one.
The different mechanics in this action makes for a different effectiveness that contradicts the natural thought of,
the higher the grit, the longer it takes

 

[LessLemming]

A little update on the Verhoeven experiments.
Apparently there seems to be some uncertainity regarding the use of the leather wheel.

Of course Verhoeven used a buffing device for the final polish in one chapter.
But in another he claims to use a leather wheel sprayed with 1µm diamond
for something about 10-15 back and forth (b&f) passes.
I do not know what he means with back and forth passes on a wheel

 

[jimmyh]

But the point was, that a razor sharpened on a 10k stone takes on the edge of the polishing compound

And that's true, if you spend enough time polishing (like with a buffer or something). Honed's point was about what happens when you polish it less than that much, which is clearly a doable thing.

I really don't think it acts any finer, more slower actually.
That is my take on why people find felt to work the best for 0.5/0.25µ diamond.
They do a bunch of laps on hard felt & get a good, smooth, very sharp edge if they "find" the window.

So we should find some of these people and see if they want to experiment with fewer laps, or balsa with a much lower density of diamonds. According to your theory, those should be equivalent to felt.

If they were doing the same on balsa or leather, they could be doing a lot less laps, but then the window is much smaller before they reach the stage where they have created new scratches instead of just polising up the scratches from the previous stone.

I don't really follow. If you drag a diamond across steel, it's gonna scratch it. Little scratches can remove big scratches, and when the scratches become small compared to the wavelength of light, the reflection becomes much more specular and less diffuse (fancy way of saying "It gets polished", but the point is that its the same mechanism).

How could it be removing scratches without scratching it, and why would it decide to start making its own scratches all of a sudden?

When you play with a belt sander, the scratch marks are a lot deeper if you're pressing against the platen than if you're using light pressure over the unsupported belt. It acts like a lower grit because each particle is pressed in further. There is no reason for this to stop happening at finer grits. You might not want to use felt to establish your 0.05um edge, but once you have it, I bet you can further refine it on felt.

Another mechanism that I can see working with the felt is a small amount of microconvexing. If done right, most of the weight can be supported behind the edge, and the very tip can be polished separately with much less pressure than you could get with tape and balsa.

My felt just arrived so I'm gonna do some tests. I bet you that a 'true' edge will get sharper on the same abrasive when I use it on the felt afterwards.

EDIT: Did the tests. it was indeed sharper after balsa then felt than it was after just the balsa. Also, the microconvexing theory is confirmed. Two razors that I had honed with microbevels (4 and 5 layers of tape) were stropped on felt with the tape removed, and the sharpness went up considerably.

 

[Brownbear]

Very informative and enjoyable thread. I've been playing with the 0.125 CBN with mixed results. But lately I have gotten good results after my coticule. I have a red cedar bench strop with the CBN and a cedar strop topped with a thin, hard and shiny layer of horse butt. I finished a Curtin and Clarke on the coticule, gave it 30 laps on the red cedar and then 20 on the horse. First shave had me doubting. The shave was smooth and a bit sharper than the coticule edge, but after my final pass and rinse, four weepers popped out of nowhere. I was thinking perhaps I'd strayed into the too sharp zone. But the second shave was quite nice and no weepers. I got 6 consecutive shaves out of the edge with normal canvas and leather stropping in between, this morning's shave pulled a little. This is pretty good for me, I never get more than half a dozen shaves out of an edge anyway. The first five shaves were smooth and sharp, and the edge hit HHT 3+ after shaving and stropping until the 6th.

I used red cedar to save the bother of glueing the balsa to the cedar. Cedar is soft and absorbent like balsa, but not quite as soft and I can get it in VG cuts. It makes a very nice strop and I assume it doesn't round the bevel as much as the softer balsa. But after reading in the threads going about micro compounds, I'm thinking maybe I'll make a strop out of some nice soft veg tanned leather I have and try that with CBN to intentionally round the last little bit of the edge. I've had some good results from a layer of tape so I'm working my way toward playing with double bevels. With the discussion above it seems that working the outer edge with a handing strop of leather and CBN could be fun.

 

[Balcmeg]

Sorry for taking this back one step - I have been busy shaving and searching for knives to hone here at home but now I´m out of them

So in your opinion you prefer balsa or leather for diamond (mono) sprays, but for poly you like to use felt in order to get a larger window where you find the "optimal edge" mainly, but not only because the felt slows down the cutting effect of the diamond?

Felt hinders a lot of the cutting action of compounds. You won't get the full effect, since the particles "hide" in the felt.

Take a felt strop & a leather/balsa strop treated w/ for instance 0.25µ micron & do 20 laps with 2 similar razors, one on each strop.
The leather/balsa stropped one will be considerably sharper. And the scratch-pattern will be much more consistent.

Sure, you can tape, I've tried it, but haven't gotten any better results with it.
And I'm not to found of fixed microbevels, they are somewhat harder to control when touching up.
If you do them freehanded, you get more control IMO.
But sure, doing a microbevel could shorten the process of course.

Not tried 0.1 diamond. The CBN does such a good job at that level that I haven't found the need to try it.

Tried newspaper, works for me kinda like a linen strop. Doesn't do much refinement, mostly smoothing & very slow mellowing effect.
Good substitute as a travel strop though!

Tried Iron Oxide. Doesn't do anything. And that sin't so strange, since it has a MOHS rating of ~6.
Hardened steel is 6.5 & above. Maybe a burnishing effect. Not for me.

Linde B?? No idea what that is I'm afraid.

The finest lapping film I've tried was 0.3µ.
Very harsh, needed to be tamed considerably.
Don't now what happens at lower grits though.

 

[LessLemming]

And that's true, if you spend enough time polishing (like with a buffer or something). Honed's point was about what happens when you polish it less than that much, which is clearly a doable thing.

Just because Verhoeven has used a buffer (and a wheel which I still not know how he used it) doesn´t mean it´s necessary.
Again, my point is: You can not distinguish between a Shapton 30.000 or a Naniwa 10.000 sharpened blade, when stropped on a chromium oxide loaded leather strop 10-15 times,
or a diamond loaded felt strop! No buffing wheels. Have you tried?

 

[Balcmeg]

I would think that it could be quite a big difference between 10-15 laps on a leather strop and a Crox covered buffer depending on how long the buffer was used. Compared to 15 laps on a 40 cm long strop, I imagine that just a few minutes with a fast rotating buffer would compare to a much longer distance.

The longer the finer CrOx is run against the edge, the closer to "CrOx optimal" the edge will get. Starting with a rougher 10k compared to 30k the 10k would need longer time to reach that optimum since it are rougher to a start. Would be interesting to know how long Verhoeven ran the buffer in order to get some comparison there, is it is close to the 10-15 laps or if it exceeds those with a larger factor. Without knowing this it is hard to make any judgements form the experiment.

Edit: I actually did find Verhoevens paper and it did not mention how long time on the buffing wheel he did. He actually did several experiments on different ways to finish an edge (5 or 6) where one was CrOx paste on leather strop and one other was AlOx on Felt buffer wheel. The way the experiments were described makes me think that he took every stop as far as possible, meaning that he would run the knives on the pasted leather strop or the buffer until any improvement could no longer be seen. I would guess that this is quite different. Too bad that he didn´t record how long each of the steels needed on the finishing materials since he did set the edge on stones varying quite a bit in grit!

Just because Verhoeven has used a buffer (and a wheel which I still not know how he used it) doesn´t mean it´s necessary.
Again, my point is: You can not distinguish between a Shapton 30.000 or a Naniwa 10.000 sharpened blade, when stropped on a chromium oxide loaded leather strop 10-15 times,
or a diamond loaded felt strop! No buffing wheels. Have you tried?

 

[honed]

That´s true and has indeed slipped my mind.

But the point was, that a razor sharpened on a 10k stone takes on the edge of the polishing compound,
not that of the 10k. For sake of comparison I will even go further and say that a Blade finished on an 8.000 JIS stone like the Naniwa Super,
will be indistinguishable from a Shapton 30.000 finished blade, after both have been stropped on a diamond or Cr2O3 strop.

Once a blade is finished, say on a 8.000 JIS stone (some would even agree that this is true for any blade with a sufficiently set bevel!)
it doesn´t take much to bring the edge to its full potential. So the jump in grits gets decreasingly important with increasing grit rating of the stone.
The jump from 4.000 to 8.000 is bigger than that from 16.000 to 30.000 (speaking Shapton grits here!),
even though both the Mesh rating as well as the micron rating are equidistant.
It may take 40 to 50 strokes to get the edge from the 4.000 to the 8.000 level,
but only 5-10 strokes from the GS 16k to the GS 30k.
That was where I was going at.

I believe there is a reason for that.
The theory is that sharpening an edge (generally spoken) consists of two different actions.
One is an abrasive action. Metal is scratched and taken off.
The second one is a flattening action, steel at very small scales will deform plastically.
Similar (not identical, though) to a alum foil. You can easily bend it any way you want.
That´s because it has a thickness of only several µm. Try doing this with a 5mm bar of Aluminium.
Sometimes there is even a chemical action, besides the physical abrasion.
This is important for polishing glass (rare earth polishing compounds are used for polishing glass),
but not so much for steel.

The theory says that with increasing fineness the abrasive action gets less important,
and the action becomes more and more a flattening one.
The different mechanics in this action makes for a different effectiveness that contradicts the natural thought of,
the higher the grit, the longer it takes

Just because Verhoeven has used a buffer (and a wheel which I still not know how he used it) doesn´t mean it´s necessary.
Again, my point is: You can not distinguish between a Shapton 30.000 or a Naniwa 10.000 sharpened blade, when stropped on a chromium oxide loaded leather strop 10-15 times,
or a diamond loaded felt strop! No buffing wheels. Have you tried?

I agree with you for the most part. Only thing that my own experiments contradicts is the theory that very few laps on a pasted strop erases the difference between a 10K & a 30K edge.
For me I have to do several progressions to get a 10K up to a level of a 30K.
Otherwise your views is very similar to my own.

And, if it works for you, then I'm glad for you.

As I initially stated, I think it is far more "rules" & "thruths" about honing as is.
If someone gets results they are happy with, then it's all good.
No matter how they did it. (Well a slight disclaimer might be in place, if it involves sacrificing of kittens or virgins, it's not OK, even if the shaves are great..)

And that's true, if you spend enough time polishing (like with a buffer or something). Honed's point was about what happens when you polish it less than that much, which is clearly a doable thing.



So we should find some of these people and see if they want to experiment with fewer laps, or balsa with a much lower density of diamonds. According to your theory, those should be equivalent to felt.




I don't really follow. If you drag a diamond across steel, it's gonna scratch it. Little scratches can remove big scratches, and when the scratches become small compared to the wavelength of light, the reflection becomes much more specular and less diffuse (fancy way of saying "It gets polished", but the point is that its the same mechanism).

How could it be removing scratches without scratching it, and why would it decide to start making its own scratches all of a sudden?

When you play with a belt sander, the scratch marks are a lot deeper if you're pressing against the platen than if you're using light pressure over the unsupported belt. It acts like a lower grit because each particle is pressed in further. There is no reason for this to stop happening at finer grits. You might not want to use felt to establish your 0.05um edge, but once you have it, I bet you can further refine it on felt.

Another mechanism that I can see working with the felt is a small amount of microconvexing. If done right, most of the weight can be supported behind the edge, and the very tip can be polished separately with much less pressure than you could get with tape and balsa.

My felt just arrived so I'm gonna do some tests. I bet you that a 'true' edge will get sharper on the same abrasive when I use it on the felt afterwards.

EDIT: Did the tests. it was indeed sharper after balsa then felt than it was after just the balsa. Also, the microconvexing theory is confirmed. Two razors that I had honed with microbevels (4 and 5 layers of tape) were stropped on felt with the tape removed, and the sharpness went up considerably.

English is not my native tounge. Maybe that is confusing things. Anyway, what I meant with the diamond in the levels of 0.5µ & 0.25µ is for many to powerful & create scratches upon the scratches & make a harsh edge.
I really can't explain the physics any better, so I leave it there, what I do know is that very many people find diamond in the to harsh & avoid it or use it one felt (that make sit cut less aggressively. And yes, I do believe if you find the sweet spot with balsa/leather the edge would be very, very hard to distinguish from a felt honed one.

I find it quite interesting that you are gonna try felt with those nano-compounds.
I only used it initially & found it as s adi a bit lacking, so it's clearly not tested enough.
Great if someone else can do it. Please share your results with us!
What type of progression stones are you planning on using?
What type of edges do you normally use/prefer?

And in closing, I must ask you to excuse me for my bad manners..

WELCOME TO B&B

Always nice to see a fresh face here in the honing section.
But I take it you are no newbie to honing & straights!

If you feel up for it, please introduce yourself HERE & I promise you'll get a way more appropriate welcome then we managed here..
Again, welcome aboard!

Very informative and enjoyable thread. I've been playing with the 0.125 CBN with mixed results. But lately I have gotten good results after my coticule. I have a red cedar bench strop with the CBN and a cedar strop topped with a thin, hard and shiny layer of horse butt. I finished a Curtin and Clarke on the coticule, gave it 30 laps on the red cedar and then 20 on the horse. First shave had me doubting. The shave was smooth and a bit sharper than the coticule edge, but after my final pass and rinse, four weepers popped out of nowhere. I was thinking perhaps I'd strayed into the too sharp zone. But the second shave was quite nice and no weepers. I got 6 consecutive shaves out of the edge with normal canvas and leather stropping in between, this morning's shave pulled a little. This is pretty good for me, I never get more than half a dozen shaves out of an edge anyway. The first five shaves were smooth and sharp, and the edge hit HHT 3+ after shaving and stropping until the 6th.

I used red cedar to save the bother of glueing the balsa to the cedar. Cedar is soft and absorbent like balsa, but not quite as soft and I can get it in VG cuts. It makes a very nice strop and I assume it doesn't round the bevel as much as the softer balsa. But after reading in the threads going about micro compounds, I'm thinking maybe I'll make a strop out of some nice soft veg tanned leather I have and try that with CBN to intentionally round the last little bit of the edge. I've had some good results from a layer of tape so I'm working my way toward playing with double bevels. With the discussion above it seems that working the outer edge with a handing strop of leather and CBN could be fun.

I did find the same thing at first when using it after a coticule & a Thüringian.
And a hangings strop or tape actually solved it.
It might depend on the scratch patter naturals normally creates.
Some folks think that it due to those "all over the place" scratches that make those edges so smooth & comfortable.
I'm not sure here myself. But it does enhance a natural edge too, but it's not as predictable it seems like after a synthetic progression.
Interesting thing with the cedar by the way!

Sorry for taking this back one step - I have been busy shaving and searching for knives to hone here at home but now I´m out of them

So in your opinion you prefer balsa or leather for diamond (mono) sprays, but for poly you like to use felt in order to get a larger window where you find the "optimal edge" mainly, but not only because the felt slows down the cutting effect of the diamond?

Felt is merely used a substrate that expands the "window"
Really doesn't matter what type of diamond-spray is used.
Even if I have found that diamonds of lesser quality has more benefits from felt then the top-of-the-line ones.


Before I step down from my trusty soap-box, I'll end with one last pompous quote from one of the finest American scientists to have ever lived;'
"Hell, there are no rules here - we're trying to accomplish something"
-TAE

There is no right or wrong here, this has abeen a great discussion & I hope the expereimentation & discuissions continues in the same spirit. We can all learn here, I sure know I do

 

[LessLemming]

Hello Stefan,

Verhoeven may have used buffing wheels, but I don´t. Please let us forget the buffing wheel, I am talking daily stropping here.
And I was asking if you actually tried wether you can feel a difference between a Naniwa Super 10k stropped on CrO3 and a Shapton 30k stropped on a Cr2O3 strop.
The strop being the usual 40 cm long strop! I cannot see (high magnification) nor feel a difference. Can you?
- Benny

10K up to a level of a 30K.

That´s interesting and somewhat unusual. I always heard Lynn, Jende etc. always talk about keeping a low profile on the high finishers
and find that to work just great. There are two options: either my ability to make out differences in sharpness are low, or your honing technique needs improvement.
Am I correct that you have the Shapton 30k and have used it directly after the Naniwa Super 10k and found that you need a progression in between?

 

[hartsore]

What a string! I, who hones on coticules and stops on mere horsehide, am humbled...

 

[mvh]

I have both the 15k and 30 shapton pro stones. Both cut amazingly fast (compared to their grit ratings) in 20 laps the 30k removed all the scratches from the 15k. Doing more strokes actually leeds to a worse edge. i can't really explain it.
If I do 20 laps on balsa with 0.5CrO it's not even close to the finish of the Shapton. It's just so much faster.

 

[honed]

Hello Stefan,

Verhoeven may have used buffing wheels, but I don´t. Please let us forget the buffing wheel, I am talking daily stropping here.
And I was asking if you actually tried wether you can feel a difference between a Naniwa Super 10k stropped on CrO3 and a Shapton 30k stropped on a Cr2O3 strop.
The strop being the usual 40 cm long strop! I cannot see (high magnification) nor feel a difference. Can you?
- Benny



That´s interesting and somewhat unusual. I always heard Lynn, Jende etc. always talk about keeping a low profile on the high finishers
and find that to work just great. There are two options: either my ability to make out differences in sharpness are low, or your honing technique needs improvement.
Am I correct that you have the Shapton 30k and have used it directly after the Naniwa Super 10k and found that you need a progression in between?

Yes, it's a nice finish to go directly to 30 from 10K, but I was once again talking about a pure or "true" 30K edge that takes some more work & not only that, but also creates 2 different kinds of edges. Going easy on the finishers is always needed.
All the heavy work must have been properly done way before on the lower grits.

 

[LessLemming]

I think I don´t understand.
After the Naniwa Super 10k the polish is flawless an the edge almost a straight line, almost!
After 10-15 strokes on the Shapton 30k the polish is still scratch free and the edge a straight line.
HHt is perfect and shaves are awesome. What do you mean then with a true 30k finish?

 

[honed]

I think I don´t understand.
After the Naniwa Super 10k the polish is flawless an the edge almost a straight line, almost!
After 10-15 strokes on the Shapton 30k the polish is still scratch free and the edge a straight line.
HHt is perfect and shaves are awesome. What do you mean then with a true 30k finish?

Well, no need to change anything for you then!
Because that is the important thing.

I use the 10K SS alot myself & really like it, but the way it make the bevel shine & look is a bit decieving.
A lot of that shine is due to polishing effect of the broke-down matrix.
So you really aren't set up to get the max out of the 30K, especially not with so few strokes without any stone / pasted strop in between.
But again, that is kind of irrelevant for you, because you are all ready getting awesome shaves.

And it's that what we are all after, right? It's not the sharpest razor that is the best, it's the one that is best honed for your face

Personally I find my own most awesome shaves lies a little but further down the keeness road, hence I push it a bit more.

 

[LessLemming]

English isn´t my native language, could you please explain to me what a broke-down matrix is?

The Naniwa Superstone 10k is indeed an awesome stone.
Under the loupe 10x, as well as under magnification with a microscope down to 160x there is no scratch at the bevel.
Nothing with direkt light source, scattered light source or direct sunlight.

Of course this comes from the polishing effect, ie. the flattening of the surface.
But what is decieving? If a bevel is polished scratchfree, and the edge (the important part) is almost free of teeth
why add another two or three stones in between the final finish?

I honestly think you can get the absolute max out of the SS10k followed by a couple of light strokes on the Shapton 30k.
If I add another layer of tape (that means polishing the very bevel) for another 10-20 strokes on the 30k,
I do not get any better results. It simply has reached the maximum then.
The same, I think applies to the SS 10k followed by a good loaded strop

But then again,
you are right. To each his own. The Shave is what is important.
The only thing that bugs me is that a newby might think
he would benefit from the Shapton 16k and 30k after the Superstone 10k,
if he uses them with a polishing compound on a strop

 

[honed]

Broke-down matrix.. I mean the binder in the Naniwa breaks down & creates this intense polishing effect.

 

[Balcmeg]

Hi Benny,
I have this peeve coming form reading literally thousands of research papers in physics and writing different reports based on market research form almost 10 years that I cannot take a comment form a scientific paper at face value but need to read the source first. Its a bad habit of mine
Also, English is not my native language (im Swedish) so sometimes the tone of what I am saying might sound different form what I actually mean!

While that makes your involvement of the paper less relevant the remaining question is - Do I feel any difference? The answer is that I have not tried yet so i have no personal reference.

While that definitely doesn´t mean that you are wrong, It also means that I am not prepared to abandon my (so far) theoretical standpoint and there is nothing to say thay they might not coincide, after all I am thinking that to get the same edge form CrOx when the finishing stone was 10k or 30k would just be that 10 k need more laps. It might very well be that the difference is 5 and 8 laps respectively, just as well as 20 vs 40 (just for example) so there are lots of opportunities for us to have the same idea here

Also, jet me join Jens in welcoming you to the forum - always nice with a new voice!

Hello Stefan,

Verhoeven may have used buffing wheels, but I don´t. Please let us forget the buffing wheel, I am talking daily stropping here.
And I was asking if you actually tried wether you can feel a difference between a Naniwa Super 10k stropped on CrO3 and a Shapton 30k stropped on a Cr2O3 strop.
The strop being the usual 40 cm long strop! I cannot see (high magnification) nor feel a difference. Can you?
- Benny

 

[LessLemming]

While that definitely doesn´t mean that you are wrong, It also means that I am not prepared to abandon my (so far) theoretical standpoint

That sounds like something I can live with