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Ken Schwartz : honing compounds [Closed, reasons noted in thread]

Posted by CliffStamp 
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Ken Schwartz : honing compounds [Closed, reasons noted in thread]
May 25, 2013 05:51PM
I have had less than ideal experiences with fine diamond abrasives recently (6 micron DMT abrasive : [www.cliffstamp.com] ) and after finding an interesting product which may have solved that problem ( Naniwa diamond water stones) asked Ken if he had used it. This lead to some discussions of his solutions which include diamond films on flat glass and sprays for stropping. Neither of which interest me significantly for issues which are mainly personal and is a preference for edge into sharpening,

There was an amusing exchange here when Ken noted that all of my problems were moot if I simply didn't have such preferences, which is true, stropping on a dense/flat medium resolves the issues. This is also a fairly practical solution but my choice for finishing with stones has been explained in depth elsewhere but mainly condenses down into the massive hype/misinformation on stropping and the influence it has on producing low quality edges and frequent problems with stone/rod honing.

Ken then suggested an idea so simple that it is almost child-like in solution, just use CBN / Diamond sprays on the same stones you prefer to finish with. This is such a great idea I think I am going to pretend that I suggested it to him. In any case I am getting :

a) 4 micron Diamond, used to load a 3K waterstone

b) 2 micron CBN, used to load a 8K waterstone

c) 1 micron CBN, used to load non-stones

(yes that means stropping).

Some references :

a) [precisesharpening.blogspot.ca]

b) [jendeindustries.wordpress.com]

A few questions :

a) does the abrasive improve the honing speed

b) are the edges sharper on a push or slice

c) is the edge retention improved

d) can blades such as ceramic be effectively sharpened

Now of course in the pass around you can also just look at these compounds on stropping media if you wish and check them against the common stropping/buffing compounds and that would be of interest and valuable.



Edited 1 time(s). Last edit at 02/27/2014 05:59PM by CliffStamp.
Re: Ken Schwartz : honing compounds
May 25, 2013 07:19PM
Cliff, I would definitely be interested in trying these. I have a 2 blades that i routinely strop to a finished edge with 1 micron diamond paste. It would be a good comparison to the cbn.
I would also like to try a loaded water stone to see it it would cut faster or leave a better finish.

Count me in.
JBN
Re: Ken Schwartz : honing compounds
May 25, 2013 08:14PM
Well, this is interesting and the outcome predictable.

Slurry stones work 'different'' than other abrasives. If you take, for example, a Cotilule slurry stone you will see that:

- with no slurry there is almost no sharpening activity.
- If you make a thick creamy slurry; you can hone a long time and this is what happens; the abrasive particles hit the edge and will take away material, but at the other end they will hit the very apex right in front off and make it blunt again. The honing at the 'sides' of the edge will go a little quicker when the edge is blunt, because it is a larger surface and the edge is actually getting sharper. So, in honing there is a optimum that is reached when the blunting is going as fast as the sharpening. At this point you can hone for years, but everything thats going to happen is that the blade gets less wide. It erodes and gets no sharper at this point because sharpening and blunting has reached an equilibrium.

At this point you start to dilute the slurry. The thinner it gets the less 'blunting' takes place, and you will see that in fact the apex gets a smaller radius. The apex cuts easier through the slurry and the blunting gets less, while the material decreasing at the edge goes on, but slower. Something that is not going to work with a thicker slurry.

You could 'enrich' a slurry with adding other abrasives like diamond and cbn, but i wonder what the effect would be. Because with each diluting phase which is necessary to get a sharper edge you lower the amount of abrasive particles instead of increasing them, to get the best result.

Of course you can add smaller abrasive particles to fade away this general effect a little, but even than the bigger particles of the stone (the number will increase and not decrease by using the diamond or cbn) will have their blunting effect on the apex anyway.

It seems to be a complicated method of using the wrong materials for the specific part of the job. I feel that trying this equals not understanding the way a slurry stone works. The effect that you are after can be reached with less equipment and material and less effort.
JBN
Re: Ken Schwartz : honing compounds
May 25, 2013 09:53PM
In addition to the above message i would want to add the following;

Sharpening is a minor complicated mechanical issue. There is no rocket science involved. The point is to get a as small as possible straight radius between two surfaces. It should preferably be as strait as possible, as small as possible and without major scratches, grooves and other disturbing anomalies. The more equal the whole thing the better it is.

It is easy to look at the 'industry' where they need sharp edges and little replacement or other time and money consuming subjects. A average industrial knife to cut card board is having a lifespan from several hundreds of thousand cuts before it is replaced to be resharpened. Dito with meat and paper and plastics.

They do not endlessly hone or strop their edges. They just found a way to have a good average between sharp and retention, using the right material and the right cutting profile. Let alone the use of machinery to make the cut in the first place instead of a wobbling human hand that causes lateral forces that are able to destroy any edge. Sharpening such an industrial knife takes less than 5 minutes to be ready for the next few hundred thousand cuts.

Sharpening is done by machines, not by hand. The same reason here. A wobbling hand will be less efficient and accurate to make the perfect straight edge that you want to have. very Coarse stones will not do any good here to. Try to get a sub micron edge nice and straight with a sharpening medium that has abrasive particles from 30 micron or so. Any heat is out of the question to. Angry clients would call why their cutting blades only last for a day instead 3 weeks.

The same industry can get a radius from 20 NANOmeter on a diamond edge without any problems. It is not so difficult to make such an edge. It is difficult to make one out of your hand, with less than optimal materials and methods. Praise the people who can do that. I can't. But.... lets not pretend it is the very best way to achieve your goal.

Stropping ect is very nice, if you have the time to spend on it. The same for the 'ceramic' steels to sharpen a knife. It is not the best way to do things, but hey, who cares if it brings fun and happiness.
Re: Ken Schwartz : honing compounds
May 26, 2013 02:00AM
Quote
JBN

It seems to be a complicated method of using the wrong materials for the specific part of the job. I feel that trying this equals not understanding the way a slurry stone works. The effect that you are after can be reached with less equipment and material and less effort.

I am interested in the effect on sharpness and edge retention of using an abrasive harder than the carbides in the steel. I had tried plates but the problem is that the very fine diamond plates are subject to issues. The alternates then are films which are very costly and fragile or pastes/compounds/emulsions, etc. . As noted previously I don't use edge trailing strokes, hence the end point of using them on stones. I am not really interested in enhancing the stones directly, that is just a side issue I am curious about given the claims. The stones are just the substrate (which I already have) for the CBN and diamonds.


Quote
JBN

The point is to get a as small as possible straight radius between two surfaces.

This is one of the points that Ken and company dispute. I raised this when people started selling extremely fine compounds such as 0.025 microns. This is 1/10 the size of the smallest apexes normally seen on edges which are about 0.3-0.5 microns so I questioned if the very fine abrasives are doing anything since the apex width is not being reduced.

The argument from Ken and company is that the fine abrasives may not be reducing the apex width but they are changing its nature as they are actually shaping the carbides directly and they claim that the blades are significantly sharper. In general most of these guys are razor guys and they are usually talking about comfort and ease of face shaving.


Quote

They do not endlessly hone or strop their edges.

I am not sure what you are responding to here. The above offer isn't part of some argument I am making that says that extended sharpening sessions of extreme lengths are practical/efficient. The video's I have on sharpening are all minimal in nature :





The reason I purchased those compounds is to experiment with the nature of a number of claims made about them and to see if sharpening with an abrasive harder than the carbides in knives will effect the sharpness/edge retention.
Re: Ken Schwartz : honing compounds
May 26, 2013 02:28AM
I have seen a marked increase in sharpness since switching to a 1 micron dmt paste from more traditional stropping/polishing compounds some in finer grits. When working with higher carbide steel s35vn specifically. I am quite curious to see how the cbn compares
Re: Ken Schwartz : honing compounds
May 26, 2013 02:36AM
Mark,

On a push or pull or both?
Re: Ken Schwartz : honing compounds
May 26, 2013 02:53AM
Strictly push cutting with those blades.
Re: Ken Schwartz : honing compounds
May 26, 2013 06:47AM
I tried putting a fine honing compound on an already fairly fine stone. It didn't seem to work well for me, but I would like giving this a try.
JBN
Re: Ken Schwartz : honing compounds
May 26, 2013 01:55PM
Quote
CliffStamp


I am interested in the effect on sharpness and edge retention of using an abrasive harder than the carbides in the steel. I had tried plates but the problem is that the very fine diamond plates are subject to issues.

What issues did you find on these very fine plates?

Quote

The alternates then are films which are very costly and fragile or pastes/compounds/emulsions, etc. . I am not really interested in enhancing the stones directly, that is just a side issue I am curious about given the claims. The stones are just the substrate (which I already have) for the CBN and diamonds.

Ok, it will be difficult to compare these films and pastes/compounds/emulsions due to the fact that the material you put them on influences the result.

I feel that the abrasives in the emulsions ect will influence the stone surface. They will mix with the stone particles and that makes it hard to tell what gives the effect. You end probably up with zero uniformity when all particles mix, and i found that uniformity is a must to get any result.
Think in this respect on the diamond stones with with all the deep scratches they cause.


Quote
JBN

The point is to get a as small as possible straight radius between two surfaces.

Quote

This is one of the points that Ken and company dispute. I raised this when people started selling extremely fine compounds such as 0.025 microns. This is 1/10 the size of the smallest apexes normally seen on edges which are about 0.3-0.5 microns so I questioned if the very fine abrasives are doing anything since the apex width is not being reduced.

Yes that is the point. Anyway; If you spread 0.025 sized particles at an 6 micron particle stone they will disappear between the stone cavities and particles sticking out of the surface. Where is the effect than?

Quote

The argument from Ken and company is that the fine abrasives may not be reducing the apex width but they are changing its nature as they are actually shaping the carbides directly and they claim that the blades are significantly sharper. In general most of these guys are razor guys and they are usually talking about comfort and ease of face shaving.

In theory that sounds sane, apart from changing the 'nature' of the edge, But: you would need a honing surface that is actually flatter than the particle size of the abrasive to do anything sensible in that respect. And it will go very slowly. Taken the fact that a very flat stone has >5 micron differences in the surface (most stones are worse) that only would make the claim less sound.
The carbides to be honed will be destroyed by the normal stone particles again.

You would need to use an fast spinning system that is incredibly flat, one of these emulsions, no pressure, and a very straight edge to begin with. It goes to the technique they use to actually shape and hone diamonds.


Quote

They do not endlessly hone or strop their edges.

Quote

I am not sure what you are responding to here. The above offer isn't part of some argument I am making that says that extended sharpening sessions of extreme lengths are practical/efficient. The video's I have on sharpening are all minimal in nature :

Ok that was one of my famous non sense remarks. You are sharpening quite quick. The remark was made thinking on a few guys that i know stropping there straight razors on real special secret leather (kangaroo, crocodile, sea cow, i don't know) without any emulsion. They think that the 'natural minerals' that of course only occur in this leather will do a great job honing the edge especially if you take 2000 strokes a side as a minimum.


Quote

The reason I purchased those compounds is to experiment with the nature of a number of claims made about them and to see if sharpening with an abrasive harder than the carbides in knives will effect the sharpness/edge retention.

Yes i understand that. It is not that i am against testing: the opposite is true. I think testing out things is the only way to verify issues. It could be interesting to see if any effect is there. How do you want to check it? 2000 x magnification? You have to see the carbides before and after to know if something happened in the first place.

I would try it on a fast spinning metal or glass plate with an enormous flatness, good cooling, no pressure, a very flat edge, and high magnification pictures before and after.

When applied on a sharpening stone the abrasives are going to interact so it will be hard to tell what does what. Apart from that the 0.025 abrasive is going to be lost in the hills and valleys from the stone i guess. When applied on your sharpening brick they all are gone within seconds.
Re: Ken Schwartz : honing compounds
May 26, 2013 06:29PM
Quote
JBN
What issues did you find on these very fine plates?

The 6-micron plate produces mainly a 6 micron finish but will consistently produce a low frequency of 10X as size scratches, initially it was higher and in fact it would produce a more coarse finish than the 25-micron fine stone.


Quote

I feel that the abrasives in the emulsions ect will influence the stone surface. They will mix with the stone particles and that makes it hard to tell what gives the effect.

It is a simple matter of using the stone with and without them to see if there is a functional difference.

Quote

Yes that is the point. Anyway; If you spread 0.025 sized particles at an 6 micron particle stone they will disappear between the stone cavities and particles sticking out of the surface. Where is the effect than?

The abrasive is usually kept the same size, so for example 4 micron diamond/cbn on a 3000 grit waterstone.


Quote

In theory that sounds sane, apart from changing the 'nature' of the edge, But: you would need a honing surface that is actually flatter than the particle size of the abrasive to do anything sensible in that respect.

I don't see why this is the case and in fact it seems trivial that this can't be true because it isn't like the apex thickness is so correlated to the stone curvature/irregularity as if this was the case you could not actually get a knife sharp on a stone which was > 20 microns from true flat as you can see a 20 micron apex which is quite blunt even by standards of people who don't sharpen edges.

Quote

The remark was made thinking on a few guys that i know stropping there straight razors on real special secret leather (kangaroo, crocodile, sea cow, i don't know) without any emulsion. They think that the 'natural minerals' that of course only occur in this leather will do a great job honing the edge especially if you take 2000 strokes a side as a minimum

You need to walk carefully around the straight razor crowd, it is often a bannable offense to actually talk about sharpening as if you were sharpening a knife because they think there is something very different happening with razors and that if you don't "get" that you are quite frankly not worth talking to and/or are just trolling. The fact that for example I have knives which have similar profiles as razors (as do many utility/disposable knives) doesn't seem to phase them.

But yes in general, it isn't difficult to find extreme sharpening times and they often don't take kindly to the question of practicality. Murray Carter set off quite a few of them with a video where he honed a straight razor and dared to claim it was perfectly functional and his procedure is extremely minimal :






Quote


How do you want to check it?

Measure the sharpness and edge retention.

Quote

2000 x magnification? You have to see the carbides before and after to know if something happened in the first place.

I am interested in results first, the why comes later, that is the theoretical part.

I just need to see if the edge is functionally sharper with greater edge retention, now if this proves to be true then the question of interest is why is it happening and the hypothesis that the carbides themselves are enhancing the performance because they are themselves producing direct cutting edges would have to be tested to confirm that it indeed the reason. There are of course other possible explanations :

-the apex just gets smaller
-there is less stress (fracture/deformation at the apex)
-the apex is non-flat at the given width

etc. .

If there is no difference then obvious the hypothesis is directly false.

(ok, to be more specific there isn't evidence it is true)
JBN
Re: Ken Schwartz : honing compounds
May 27, 2013 01:46PM
Quote
CliffStamp


The 6-micron plate produces mainly a 6 micron finish but will consistently produce a low frequency of 10X as size scratches, initially it was higher and in fact it would produce a more coarse finish than the 25-micron fine stone.

Ha, that might be caused by an enormous amount of clustering of the particles, getting you in the 500 micron range or so. This is the specific reason i do not use diamond stones. Ok, there are a few other reasons as well, but this one is a important one.

Quote

It is a simple matter of using the stone with and without them to see if there is a functional difference.

I am curious to the results. We will see.


Quote

In theory that sounds sane, apart from changing the 'nature' of the edge, But: you would need a honing surface that is actually flatter than the particle size of the abrasive to do anything sensible in that respect.

Quote

I don't see why this is the case and in fact it seems trivial that this can't be true because it isn't like the apex thickness is so correlated to the stone curvature/irregularity as if this was the case you could not actually get a knife sharp on a stone which was > 20 microns from true flat as you can see a 20 micron apex which is quite blunt even by standards of people who don't sharpen edges.

I doubt it. Normally you set up the ' cutting depth' of an abrasive stone on 1/3 - 1/4 the particle size. Choice of the matrix is important than because you only want particles sticking out of the surface for some hight, and if they get higher they brake, leaving a fresh cutting surface. But if you use separate particles than it is another story. You have the full size of the particles available now, which is about 4 times bigger (if they are uniform in shape) than the normal 'grit' in microns you think you have. This would mean that a 8 micron stone has the same effect as 2-3 micron loose particles.

Because this loose particles are not bond to anything they tend to move and roll over the surface. With a coarser surface they get stuck in the valleys of the stone and do nothing.

If you use 6 micron loose particles on a 6 micron stone, the loose particles will be bigger than the fixed particles sticking out the stone, and you actually make the stone coarser. The loose particles will abrade the metal and the stone at the same moment.


Quote

You need to walk carefully around the straight razor crowd, it is often a bannable offense to actually talk about sharpening as if you were sharpening a knife because they think there is something very different happening with razors and that if you don't "get" that you are quite frankly not worth talking to and/or are just trolling. The fact that for example I have knives which have similar profiles as razors (as do many utility/disposable knives) doesn't seem to phase them.

I found out yes. You have quite normal razor people, but i once had a discussion with one that wanted a 'jig' to get an more precise edge. Than i told him that a razor had a onboard jig, which is the spine, and how he could calculate the angle with the spine thickness and the width of the blade from spine to edge. He than advised me to get another profession because it was very clear that i did not get the most simple details in life.
Very amusing though.

Quote

But yes in general, it isn't difficult to find extreme sharpening times and they often don't take kindly to the question of practicality. Murray Carter set off quite a few of them with a video where he honed a straight razor and dared to claim it was perfectly functional and his procedure is extremely minimal

I tend to like Mr. Carter. He is quite consistent in his movies and he tries to learn other people what he thinks is right. Ok, he might not have all facts concerning edge and carbides ect. right, and the whole thing is a little commercial which is logical considering his business, but it is his own way and he sticks to it. I can appreciate that. And he sharpens quite fast.


Quote

How do you want to check it?

Measure the sharpness and edge retention.

Quote

2000 x magnification? You have to see the carbides before and after to know if something happened in the first place.

Quote

I am interested in results first, the why comes later, that is the theoretical part.

I just need to see if the edge is functionally sharper with greater edge retention, now if this proves to be true then the question of interest is why is it happening and the hypothesis that the carbides themselves are enhancing the performance because they are themselves producing direct cutting edges would have to be tested to confirm that it indeed the reason. There are of course other possible explanations :


If there is no difference then obvious the hypothesis is directly false.

(ok, to be more specific there isn't evidence it is true)

Lol, thanks for being more specific!

If you are testing with cutting card board or something you have three possible options basically:

-The edge cuts better
-There is no difference
-The edge cuts worse

Carbides honed or not, you could have all three outcomes and it would be interesting to know why that is. Also in answering your own points:

Quote

-the apex just gets smaller
-there is less stress (fracture/deformation at the apex)
-the apex is non-flat at the given width


You get a better understanding why all these or other factors influence the results. Only the cutting test will say very little. And if you want to prove the carbides got honed (or not) you need to check that imo.

It might be interesting to do that with other knives as well.



Edited 1 time(s). Last edit at 05/27/2013 01:52PM by JBN.
Re: Ken Schwartz : honing compounds
May 27, 2013 02:42PM
Quote
JBN

Ha, that might be caused by an enormous amount of clustering of the particles, getting you in the 500 micron range or so. This is the specific reason i do not use diamond stones. Ok, there are a few other reasons as well, but this one is a important one.

Yes, hence the main promotion of the Atoma's which have a much more uniform deposit.


Quote

If you use 6 micron loose particles on a 6 micron stone, the loose particles will be bigger than the fixed particles sticking out the stone, and you actually make the stone coarser. The loose particles will abrade the metal and the stone at the same moment.

Yes this is why they normally go slightly finer, but again this isn't to actually make the stone cut finer, it is to make it cut differently, basically to try to make essentially a kind of home-made DMT plate which can be :

-easily resurfaced
-trivially cleaned
-very durable

etc. . because of course it is just a waterstone which can be lapped and then just add a bit more diamond/cbn when you sharpen . The claim is that even a drop of the emulsion actually makes a pronounced effect and thus you are looking at on the order of 10^3 uses from even a small bottle.

Quote

He than advised me to get another profession because it was very clear that i did not get the most simple details in life.

When you deal with crazy people the only solution is to be crazier than them, if he had asked me that I would have started discussing the details of edge apex stability in phase space.

Quote

Only the cutting test will say very little.

It will say if there is a difference, if there isn't one then it stops there, if there is one then the question becomes why as there are many possible reasons the simplest is just placebo/bias so that has to be eliminated first. Then if desired eliminate all other possibilities bit by bit.

There are also very simple methods to check if it is a carbide cutting issue by simply sharpening steels where this could not be an issue and seeing if the performance again is similar.

For example if the edge is sharper using simple white steel (1095) then it isn't the fact that the diamond/cbn can cut the vanadium carbides which is the issue.
JBN
Re: Ken Schwartz : honing compounds
May 27, 2013 10:03PM
Quote
CliffStamp

Yes this is why they normally go slightly finer, but again this isn't to actually make the stone cut finer, it is to make it cut differently, basically to try to make essentially a kind of home-made DMT plate which can be :

-easily resurfaced
-trivially cleaned
-very durable

etc. . because of course it is just a waterstone which can be lapped and then just add a bit more diamond/cbn when you sharpen . The claim is that even a drop of the emulsion actually makes a pronounced effect and thus you are looking at on the order of 10^3 uses from even a small bottle.

Well, in that case you might take the abrasive a bit smaller and take a glass or marble plate or something as an underground. No reason to spoil a waterstone it seems.

Quote

When you deal with crazy people the only solution is to be crazier than them, if he had asked me that I would have started discussing the details of edge apex stability in phase space.

Yeah, the next time i will start about the 5 th dimension and apex stability in time.

Quote

Only the cutting test will say very little.

Quote

It will say if there is a difference, if there isn't one then it stops there,

Ok, this does not sound logical to me. If there is no difference in cutting there still might be a difference in the maybe honed carbides. (Which is part of the claim) If you stop after seeing that there is no difference in cutting you can not wipe that other part of the claim from the table.
Re: Ken Schwartz : honing compounds
May 27, 2013 11:09PM
Quote
JBN
Well, in that case you might take the abrasive a bit smaller and take a glass or marble plate or something as an underground. No reason to spoil a waterstone it seems.

Adding cbn / diamond to it can't ruin it outside of some sort of purist sense. Plus the same contamination can happen when the stone is lapped and obviously happens when it is in use as there are steel/carbide particles ground into it from the knife.

Yes you could use the suspension direction on many media in an edge-trailing motion that isn't what I am interested in.

The coating would also not be uniform enough to use on float glass by itself as I don't imagine the contact direct against the glass is going to be useful as it is highly likely to stress the edge without abrasion.

However that would be a curious experiment in its own right, I will likely pick up some float glass as I want to check and see how durable are the diamond films that you can buy for very little cost and thus make diamond plates.


Quote

If there is no difference in cutting there still might be a difference in the maybe honed carbides. (Which is part of the claim) If you stop after seeing that there is no difference in cutting you can not wipe that other part of the claim from the table.

It is obviously and trivially true that a diamond particle will readily cut into a piece of vanadium carbide it isn't so trivial to assume that this effect produces a meaningful result in regards to sharpness and edge retention.

I am interested in the latter, if you are interested in the former by all means investigate it.
JBN
Re: Ken Schwartz : honing compounds
May 29, 2013 11:25AM
Quote
CliffStamp
The coating would also not be uniform enough to use on float glass by itself as I don't imagine the contact direct against the glass is going to be useful as it is highly likely to stress the edge without abrasion.

Yes, i use the glass plate only for abrasive paper and flattening a stone, (or sharpening a knife with that paper)

Quote

However that would be a curious experiment in its own right, I will likely pick up some float glass as I want to check and see how durable are the diamond films that you can buy for very little cost and thus make diamond plates.

You could consider to add the abrasive slurry to 3M sandpaper and see what happens there.
I believe 3M has sandpaper with sub micron particles too. That should be able to hone carbides.


Quote

It is obviously and trivially true that a diamond particle will readily cut into a piece of vanadium carbide it isn't so trivial to assume that this effect produces a meaningful result in regards to sharpness and edge retention.
I am interested in the latter, if you are interested in the former by all means investigate it.

Yes i might do that. It seems interesting to see what actually happens with the carbides.
Edit: I am quite a visual guy. I even think like that.



Edited 1 time(s). Last edit at 05/29/2013 11:27AM by JBN.
Re: Ken Schwartz : honing compounds
May 29, 2013 04:14PM
Sandpaper I have always seen as a curious option assuming you use knives significantly because it is extremely expensive. It does not appear to be maybe at first glance but just look at the amount of abrasive on a sheet of sandpaper compared to what is found in a stone.

I have worn out stones before, in particular the large green silicon brick from Lee Valley, but it takes years of using that as your primary shaping stone and sharpening on average at least one knife a day which requires significant shaping, basically this is on the order of 10^3 sessions. With finer stones I don't see it ever happening because sharpening removes such minimal amount of material that it is on the order of 10^4 sharpening.

However sandpaper not only wears out fairly rapidly it is also subject to tears, cuts and general contamination/damage. Even assuming you can use Sandpaper 10X before it isn't efficient, you still need 1000 sheets to give the lifetime of one fine stone and high quality sandpaper generally is more than $0.10 a sheet, especially if you are after silicon carbide, CBN or diamond abrasives, these can cost 10X that much easily.

But yeah those guys who carry a knife and sharpen it 1-2 times a year and just "strop" it occasionally, why invest in a stone, just buy $10 worth of sandpaper, it would last forever.

As an aside, the CBN guys in india will make CBN stones and they minimum order they want is only five units which is very surprising as they will custom make them any way you want (size, grit, substrate, bond, etc.). I am going to go ahead and get five units of something, it will either be finer than the 600 DMT or the 1200 DMT depending on if the 1200 DMT is sensible or spazzes like the m-x-f DMT is still doing. I obviously don't need 5 of the same hone so once I get it worked out I will see who wants the other 4.
Re: Ken Schwartz : honing compounds
May 29, 2013 04:58PM
Pm me I may take one depending on price / size etc... But I would like to try.
I have a 600 DMT and a 1200 what about something in between



Edited 1 time(s). Last edit at 05/29/2013 05:00PM by Mark a.
JBN
Re: Ken Schwartz : honing compounds
May 29, 2013 10:06PM
Ok, are these the sticks? or do they have different sizes as well?
JBN
Re: Ken Schwartz : honing compounds
May 29, 2013 10:38PM
Quote
CliffStamp
Sandpaper I have always seen as a curious option assuming you use knives significantly because it is extremely expensive. It does not appear to be maybe at first glance but just look at the amount of abrasive on a sheet of sandpaper compared to what is found in a stone.
But yeah those guys who carry a knife and sharpen it 1-2 times a year and just "strop" it occasionally, why invest in a stone, just buy $10 worth of sandpaper, it would last forever. .

That is a factor yes, if you look to 10$. You can buy big sharpening stones out of China for 1$ if you look around. See www.alibaba.com and fill in "sharpening stone". You would be surprised. They all want to you take 5, but if you ask a sample first they will send one as well. Nothing new there and in India it is the same story.

The price is not to interesting for me. I am looking for efficient methods to sharpen. Sand paper is, however maybe expensive compared to a stone and not so practical quite efficient, fast, and you can get a great edge with it. You don't have to get it flat, it is a nice big surface, and the only thing you need with it is a piece of glass and some water. Not to bad i think.

The same thing for the Coticule waterstones from Belgium. If you buy a large one you pay 200-400$. Is it worth it? probably not. But it is fun to have. Even when i hardly use it.

This price issue is only one of the several factors that determines how interesting or efficient something is imo.
Re: Ken Schwartz : honing compounds
May 29, 2013 10:55PM
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JBN
Not to bad i think.

It isn't but I sharpen a lot, I would be using sheets of paper a day which is not only a tremendous cost it is a significant waste, it has no advantage and I am paying more for a less durable and versatile product which produces bags of garbage readily, that seems kind of silly. But yes, if you don't sharpen very often large stones are a waste obviously.

I do wish someone would take the japanese naturals and cut them in slices and bond them to plates. I have a hard time buying a stone when I know that it is going to be wasted as I will use at most 10% of it in my lifetime at most. It isn't the money directly, again it is just the waste to buy something which I will never fully use.



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JBN
Ok, are these the sticks? or do they have different sizes as well?

They will make plates of any size you want.
JBN
Re: Ken Schwartz : honing compounds
May 29, 2013 11:11PM
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CliffStamp
It isn't but I sharpen a lot, I would be using sheets of paper a day which is not only a tremendous cost it is a significant waste, it has no advantage and I am paying more for a less durable and versatile product which produces bags of garbage readily, that seems kind of silly. But yes, if you don't sharpen very often large stones are a waste obviously.

Yes ok. I don't sharpen on a daily base. You do a lot of testing of course. And you are quite right about (really) large stones being a waste.

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I do wish someone would take the japanese naturals and cut them in slices and bond them to plates. I have a hard time buying a stone when I know that it is going to be wasted as I will use at most 10% of it in my lifetime at most. It isn't the money directly, again it is just the waste to buy something which I will never fully use.

Well, if that is your biggest wish i could arrange that. Lol. But.... if you have a few more weeks patience i might have a better option.

Say; if you should have a choice, what grit would you like to test. Starting from 1000 till 30,000.

Specs: resin bond, shape: round (circle) 150-200 mm diameter. Base: aluminum plate 5-10 mm. Abrasive layer: 1-3 mm. Flatness: < 2 micron. Abrasive: CBN mono.



Edited 2 time(s). Last edit at 05/29/2013 11:13PM by JBN.
Re: Ken Schwartz : honing compounds
May 31, 2013 03:24PM
Why resin bond?

I have used the Atoma plate (1200 grit - 13 microns) and it is appears at first little experimenting to not have the extreme deviations in scratch patterns that the DMT did so of interest would be 6-8 microns and 2-4 microns.

In general I find it hard to understand how the very fine compounds are actually doing anything productive at the edge considering they are smaller than what is likely stable at the edge.

If you look at some of the high magnification shots that these people often use (400X), then going to UF compounds of the 0.1 micron and smaller have no effect on the straightness/condition of the edge, they just produce a nicer polish on the flats.

In fact slurry stones constantly produce more even edges, but that is likely simply due to the direct edge-abrasion you noted with a slurry.

Yes, I could just buy a stone, cut it up and sell off the pieces but unless you are doing that as a living then you can easily end up wasting more money. I just need to make friends with someone who has a fondness for japanese naturals.
JBN
Re: Ken Schwartz : honing compounds
May 31, 2013 03:48PM
A resin matrix has a better bond to the particles, especially when they get smaller. It is a little more though and flexible. Further you can adjust the hardness of the matrix better, and the production process is easier. However, i am going to experiment with Kaolin and Mullite, the clay they make porcelain from. We will see which is better for every (particle) grain. That is why i make test stones.

The effect of the small particles much less than 1 micron is there. The only thing is that you need a higher speed with decreasing particle size and cutting depth to see the effect. Hand sharpening is a little to slow than. 0.25 micron abrasives do well on a fast spinning leather wheel or metal disk.

Why do you want to have the Japanese natural water stones specifically? It is quartz in a (stoned) clay matrix. (Which is the reason i want to test Kaolin) But however, if you can get a Japanese stone i know some companies that can cut it up quite easily. The only thing you have to be aware of is the hidden fault lines that might be inside the stone and could cause the whole thing to break.

It would be easier to take quartz particles and put them into a matrix.

After the meeting with the abrasive people i think i might found a better way to make diamond sharpening stones as well. Nevertheless, i go for CBN.
Re: Ken Schwartz : honing compounds
May 31, 2013 05:24PM
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JBN

The effect of the small particles much less than 1 micron is there.

What is it doing exactly? The apex width's don't decrease from the numbers I have seen, they are still 0.3 to 0.5 micron, so what is a 0.025 or similar micron abrasive doing at that point?

Now I can understand maybe the apex width is changing in nature somehow, but still I think the thickness itself has to be dominant and if a steel can't form/hold a 0.1 micron apex then what is the point of a less than 0.1 micron abrasive?

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Why do you want to have the Japanese natural water stones specifically?

To check many of the claims made, curiosity. I don't think any of them are true at all, but it never hurts to check. Plus maybe I have a little inner weeaboo .

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After the meeting with the abrasive people i think i might found a better way to make diamond sharpening stones as well. Nevertheless, i go for CBN.

For hand sharpening?

The other thing which is kind of amusing is the only benefit to diamonds/cbn is the ability to cut the vanadium carbides, this is only going to be relevant at very high polishes (at low grits the scratches are much bigger than the vanadium carbides anyway) and those steels don't work well at those polishes anyway.

In short I think it is only an academic curiosity, now maybe there is a benefit in edge holding - maybe, but I have not seen it to date or even heard anyone claim it despite the massive influx of diamond plates. Generally they are promoted because :

-only light water spray required (or can be used dry - not recommended for health reasons alone)
-come and stay flat
-can sharpen anything including carbide/ceramics
-lower cost than many alternatives (waterstones, ceramics, etc. all can be much more)
-cut very fast
-consistent grit

The latter is proving problematic for some at high grits.
JBN
Re: Ken Schwartz : honing compounds
June 01, 2013 03:37PM
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CliffStamp
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JBN

The effect of the small particles much less than 1 micron is there.

What is it doing exactly? The apex width's don't decrease from the numbers I have seen, they are still 0.3 to 0.5 micron, so what is a 0.025 or similar micron abrasive doing at that point?

Now I can understand maybe the apex width is changing in nature somehow, but still I think the thickness itself has to be dominant and if a steel can't form/hold a 0.1 micron apex then what is the point of a less than 0.1 micron abrasive?

It is not quite clear for me what it not clear about it..

Sub micron abrasives do the same thing as plus micron abrasives. Sanding away material. The latter make bigger scratches and the former smaller. Abrading they do all.
This means that you could use 0.25 micron particles to hone a piece of metal to dust. Of course it is slower than when you use a larger particle size.

If you try to make a 0,3 micron edge or radius smaller, say towards 0.1 micron you have to take away 0.1 micron material on each side of the edge. It is not very logic to use coarse abrasives, 10 or 20 micron, for it. The bigger particles will tear away material, make relatively big grooves that might be bigger than the size you want to transform the apex into. These grooves could cut easily through the very apex, making an interesting saw blade but that is something different.




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JBN
Why do you want to have the Japanese natural water stones specifically?

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CliffStamp
To check many of the claims made, curiosity. I don't think any of them are true at all, but it never hurts to check. Plus maybe I have a little inner weeaboo.

What, is weeaboo?

Some cut quite good. Some less good. They real stuff is very hard to find, and quite costly.

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After the meeting with the abrasive people i think i might found a better way to make diamond sharpening stones as well. Nevertheless, i go for CBN.

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For hand sharpening?

Yes, for hand sharpening. I don't think the diamond stuff that is used on these plates is the type that is best for the job.

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The other thing which is kind of amusing is the only benefit to diamonds/cbn is the ability to cut the vanadium carbides, this is only going to be relevant at very high polishes (at low grits the scratches are much bigger than the vanadium carbides anyway) and those steels don't work well at those polishes anyway.

In short I think it is only an academic curiosity, now maybe there is a benefit in edge holding - maybe, but I have not seen it to date or even heard anyone claim it despite the massive influx of diamond plates. Generally they are promoted because :

-only light water spray required (or can be used dry - not recommended for health reasons alone)
-come and stay flat
-can sharpen anything including carbide/ceramics
-lower cost than many alternatives (waterstones, ceramics, etc. all can be much more)
-cut very fast
-consistent grit

It is not only the fact that diamond/CBN cuts Vanadium, Tungsten and other carbides, but also cuts the steel matrix much easier. So easy that you end up with Grand Canyon like grooves. Especially with the coarser types. The very material they use to make the plates is also the reason that you always will have a non consistent grit.

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The latter is proving problematic for some at high grits.

Yeah, and all other grits as well. Cheap material, bad results.

Well, is hasn't have to be this way. They grind and polish big diamonds with diamond abrasives. Do you think those people would appreciate it when they are almost done to discover a large scratch at the surface so they can start all over again?
Re: Ken Schwartz : honing compounds
June 01, 2013 08:45PM
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JBN
It is not quite clear for me what it not clear about it..

It should be obvious that there is some limit to the apex width that can be formed and that which can be expected to be stable for any length of time due to the physical limits of the steel (aus-grain, primary carbide size, etc.). This is evident physically in measurements of apex widths which are typically 0.3 to 0.5 microns. If you are using an abrasive which is ten times smaller than this, then what is practically being achieved?

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If you try to make a 0,3 micron edge or radius smaller, say towards 0.1 micron you have to take away 0.1 micron material on each side of the edge.

That is the point, there is no documentation that the are achieving such very small apex widths, plus even if you could achieve them it certainly isn't trivial to assume they will be stable. As one obvious point, this isn't done in razor blades which has a tremendous amount of money behind it to produce superior ones so again I would ask where is the evidence that these extreme fine abrasives are actually achieving anything functional behind producing very fine finishes on the flats?

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What, is weeaboo?

It means someone who likes something japanese simply because it is japanese.

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It is not only the fact that diamond/CBN cuts Vanadium, Tungsten and other carbides, but also cuts the steel matrix much easier. So easy that you end up with Grand Canyon like grooves. Especially with the coarser types.

Simply because it is harder doesn't mean it cuts it better. The reason that a harder material cuts a softer one is simply because when the two materials meet the one which can have the highest yield point won't deform before the other will deform or fracture, once you exceed that it doesn't become better to exceed it even more, that doesn't make it cut better. The harder material can have advantages in other areas such as long term wear, but cutting ability is also influenced by the nature of the abrasive (round vs pointed) which influences the pressure in the contact and of course the size of the abrasive. A 50 micron quartz particle leave a much harsher scratch than a 5 micron diamond one.

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The very material they use to make the plates is also the reason that you always will have a non consistent grit.

The grit isn't always non-consistent, as noted I have many plates which are extremely consistent. In general there are only two complaints about issues with diamond stones and scratch patterns and it is with the XXF DMT and the recent MXF DMT, the other ones (and the Atoma's) are generally well regarded. Now with the cheaper stones yes, the diamond stones which are $1 or so often have problems, but that is no different than any really cheap product. I have extremely cheap water and oil stones which have very inconsistent behavior as well.



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Yeah, and all other grits as well. Cheap material, bad results.

This isn't the case. Now I appreciate providing information, but you are moving beyond than and just making generalizations which are trivially false.

I have many diamond stones which have been producing consistent scratch patterns for literally more than a decade. I have them up to ~10 microns with the recent Atoma plate which is very consistent and produces a similar finish as a 1000 grit King. For a lot of people that is a fine edge, as for example fine india stones are very popular here and they are much more coarse so it is easy to get consistent diamond stones to satisfy that class of users.It is trivial to find high magnification shots, up to 400X showing consistent scratch patterns with diamond abrasives and this information has been out there for years. Ken's stones which are films on flat glass can take this up and beyond the micron-level.
JBN
Re: Ken Schwartz : honing compounds
June 02, 2013 01:57PM
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CliffStamp


It should be obvious that there is some limit to the apex width that can be formed and that which can be expected to be stable for any length of time due to the physical limits of the steel (aus-grain, primary carbide size, etc.). This is evident physically in measurements of apex widths which are typically 0.3 to 0.5 microns. If you are using an abrasive which is ten times smaller than this, then what is practically being achieved?

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If you try to make a 0,3 micron edge or radius smaller, say towards 0.1 micron you have to take away 0.1 micron material on each side of the edge.

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That is the point, there is no documentation that the are achieving such very small apex widths, plus even if you could achieve them it certainly isn't trivial to assume they will be stable. As one obvious point, this isn't done in razor blades which has a tremendous amount of money behind it to produce superior ones so again I would ask where is the evidence that these extreme fine abrasives are actually achieving anything functional behind producing very fine finishes on the flats?

Ok, to prevent that we have an Babylonian speech thing i will try to explain myself better.

Abrasive particles in a matrix are sticking out the matrix for some height. A part of this height will have a certain cutting depth by a given cutting speed and pressure.

Something like this:



For discussion reason only we can assume a few things, for example that the cutting depth is 1/2 of the part of the abrasive particle that sticks out the matrix. (This will be influenced greatly by pressure, shape, speed of the particle ect) We have to assume that the particles stick out the matrix very uniform in shape, size and position to cover the complete surface from the piece we want to sand in one rotation.

If you want to remove 100 nanometer of material it would not be logically (for me) to use a particle size that cuts 200 nanometer deep. It would cut through the layer in only one rotation, and i don't want to cut through this 100 NM layer. Because i would want to guide the process to be able to do the abrading very accurately, i would want to have 300 rotations minimum before i reach the bottom of the 100 NM i want to remove.

If we take a speed from 300 rpm we would need 1 minute to cut this 100 NM layer with a average cutting depth from 0,33 NM which would mean a particle size sticking out the matrix from 0,66 NM.

Of course you could use only one rotation with a cutting depth of 100 NM, (Particle size 0,2 micron above matrix or say 0,5 micron in total or so) and in this example it would work because we assume that all particles are even and equally high and so on, and the complete layer would be removed in just one rotation.

In reality of course the matter is much more complex, which would mean that in the first example you would have a small chance to succeed, but in the second one the chances are almost zero. I need to simplify the problem this way to make more clear what i mean.

Now, i don't think it is handy to shape a blade with a sub micron grit. You actually could do it, -when material is abraded away you are actually cutting and the blade will get smaller- but it would take a long time and lots of abrasives. For practical reasons it would be better to take a more coarse abrasive to speed up things. But at the other hand trying to remove only 100 NM with a particle size that cuts a 10 fold is not to logically either.



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What, is weeaboo?

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It means someone who likes something japanese simply because it is japanese.

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Simply because it is harder doesn't mean it cuts it better. The reason that a harder material cuts a softer one is simply because when the two materials meet the one which can have the highest yield point won't deform before the other will deform or fracture, once you exceed that it doesn't become better to exceed it even more, that doesn't make it cut better. The harder material can have advantages in other areas such as long term wear, but cutting ability is also influenced by the nature of the abrasive (round vs pointed) which influences the pressure in the contact and of course the size of the abrasive. A 50 micron quartz particle leave a much harsher scratch than a 5 micron diamond one.

It is quite nice to see you jump the conclusion for a change. I did not state that diamond cuts steel better because it is harder. Diamond is a very efficient cutter because all the combined properties. That includes hardness but also the immense pressure resistance and relative toughness. It will hold a sharper shape longer, and can handle more pressure and heat better than for example Aluminum oxide. Therefore it cuts steel and a lot of other things easier. That is what i stated in the former message.

In this perspective it looks like CBN, that is slightly softer, but tougher and cheaper if you compare the right grades.

You do not need always a excessive hardness difference between the abrasive and the material you want to abrade, diamond is honed with diamond. Other properties are as or even more important.

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The grit isn't always non-consistent, as noted I have many plates which are extremely consistent. In general there are only two complaints about issues with diamond stones and scratch patterns and it is with the XXF DMT and the recent MXF DMT, the other ones (and the Atoma's) are generally well regarded. Now with the cheaper stones yes, the diamond stones which are $1 or so often have problems, but that is no different than any really cheap product. I have extremely cheap water and oil stones which have very inconsistent behavior as well.

From what i hear from people that use diamond stones it is more the rule than the exception that the grit is not very consistent in general and often makes one or more deep scratches compared to the average grit uniformity at the stone. My own experience tells me the same thing. I owned three diamond stones in several grit sizes, the smallest being 1000, and they all had this problem. I saw several other people here at the forum that had the same issue.

Now one of the reasons that it is worse for me than for you (maybe i don't know) could be me having the habit of making polished edges. You make much coarser ones if i look to your photo's so probably you wouldn't notice a deep scratch at all without magnification. 1000 grit is the coarsest i would ever use, and than only for bad edge damage.

(That is another reason why i like to use very fine sand paper. The uniformity is very high on those sheets)

If i make a polished edge with a lot of trouble using 4 or 5 different grits and a giant scratch appears in the last stage i am not amused.




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Yeah, and all other grits as well. Cheap material, bad results.

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This isn't the case. Now I appreciate providing information, but you are moving beyond than and just making generalizations which are trivially false.

Well, thank you and Yeah, i might have a reverse weeaboo on diamond plates. Thats why the peer review was invented. We use it all the time. But i will clarify my remark a bit;

If you buy diamond (or CBN) abrasives particles there are certain properties to select. Shape, material density, the way they brake, the moment that they brake, coating, impurities and a lot more.

All these properties have an important influence on the price you pay for the abrasive. Take size (and thus grit uniformity) for example. In China you can buy diamond for almost nothing. It goes from a few cents per gram till many hundreds of dollars per gram.

Now the cheap variant has always, that means without exception, a very large window for the size (and also for some other properties)
I actually saw windows from a 4 micron particle that went from 2 to 8 micron. And not consistent. One shipment can be much different than another. The smaller you want to have this window the more expensive they get. Even with the more expensive ones you talk about a relatively large window. Say 0-1 micron, or 2-3 micron.

If you look at the price for all diamond plates in the store you realize that they must have used the cheaper variants. In the quality i would select the material price only would be much higher than the shop price for complete plates. The scratching phenomenon as discussed above is mostly found in the cheaper sorts. You will not find it in the 'better' sort.

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I have many diamond stones which have been producing consistent scratch patterns for literally more than a decade. Ken's stones which are films on flat glass can take this up and beyond the micron-level.

If the diamond stones work well for you, that is fine by me. I think i also mentioned that in another threat. For me the negative aspects are reason not to buy a single one. I never used the glass plates from Ken and i do not know him. If you say they work well even on a sub micron level i have no reason to doubt that, but i have no evidence to confirm it either.
When i ever try one of the Ken's plates i will give a fair and peer reviewed judgment.

Well, Mr. Stamp, did i succeed this time in making a more clear message?

If not i will consider a English course.
Re: Ken Schwartz : honing compounds
June 02, 2013 02:55PM
Quote
JBN

If you want to remove 100 nanometer of material it would not be logically (for me) to use a particle size that cuts 200 nanometer deep. It would cut through the layer in only one rotation, and i don't want to cut through this 100 NM layer. Because i would want to guide the process to be able to do the abrading very accurately, i would want to have 300 rotations minimum before i reach the bottom of the 100 NM i want to remove.


One of the problems we are having in this discussion is the inter-switching between hand and power sharpening as they are very different simply due to the speed of metal removal. If was going to sharpen on a belt sander then I would use very fine abrasives for the reason you noted because I would not want the rate of metal removal to be that high that one pass would be all that is needed because you have no ability to correct a mistake, no ability to tune depth of cut, etc. . But I am speaking of hand sharpening, again just look at the title of this thread, it is above abrasives which are applied to a substrate to make a pseudo-stone for hand sharpening.



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From what i hear from people that use diamond stones it is more the rule than the exception that the grit is not very consistent in general and often makes one or more deep scratches compared to the average grit uniformity at the stone.

This tends to be mainly dominant on the finer stones and there are a few things which seem obvious here, for one just look at it on a percentage scale if you look at things like :

-grit presentation
-depth of bond
-size variance

If these things can produce a random influence on the order of 1-5 microns then on the very coarse stones they would produce a minor percentage effect so the consistency is going to be very high, however if the scratch pattern is supposed to be on the order of 1-5 microns then these types of variances can be on the order of the scratch pattern themselves.

The other thing which seems likely to be is that people are going to be far more sensitive to even seeing scratch difference when the polish gets very fine because usually :

-their sharpness tolerances are higher
-angles are lower and edges are thinner (amplifying the effects)

Before I bought the new series of fine diamond abrasives then I did some net-scans and the reports are very inconsistent with some people reporting that the 1200 DMT was perfectly fine but other reports of noting that it was not, and some of them noted it could be improved with ceramic lapping and some noted it could not. Again the big issue here is are you seeing differences in the stones or just difference in the ability of people to see differences in the stones?


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I never used the glass plates from Ken and i do not know him. If you say they work well even on a sub micron level i have no reason to doubt that, but i have no evidence to confirm it either.

There is lots of data available on that both from Ken who had it measured directly, as well from those who have used it, you can find both commentary and high resolution pictures. Note however they are very expensive, they are basically sandpaper but they cost as much as the DMT plates and he will be open about the fact that edge-leading strokes can damage them. So if you wanted to look at an expensive diamond product his is the highest, second only to the diamond-water stones.

In regards to the downsides, again this thread is about hand-honing compounds and while it is known that Diamond has problems with grinding ferrous materials at high speeds care needs to be taking to interjecting that into a discussion because the issues are not issues in hand honing. As a trivial example, Ken's products can not be used in power grinding, they would be mangled immediately (the plates he sells) but this would not be a reason to rule them out for hand sharpening.

As for diamond vs cbn, I don't think anyone here wants diamond stones for the sake of diamonds, it is simply the case that it is trivial to get diamond plates and they have many advantages :

-come flat
-require only a little water
-are available in xx-c to xx-f grits
-not expensive
-can cut even the hardest and high alloy of steels
-can even cut ceramic and carbide tools
-are available in various shapes, rods, files
-can be used to lap other stones, including solid ceramic plates

Now if CBN hones are available then in what way are they going to be superior exactly and again we are talking about hand honing so the problems that diamond has an an abrasive are not limitations for that. Now can you get a CBN product which is :

-as flat
-similar in grit range, cutting speed

and is more consistent in scratch pattern. Then it is likely that you could make significant inroads into the diamond plate/file market. But marketing is going to be problematic outside of a small few people who know what CBN is because you are selling a softer/cheaper abrasive, that is how it is going to be perceived.

But if you can get it then I would be interested in a few plates and I would imagine so would a few other people here so if you can make it happen just let me know. Even if it doesn't actually prove to be functionally superior I would be curious to know / experiment anyway.
JBN
Re: Ken Schwartz : honing compounds
June 04, 2013 01:25PM
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CliffStamp

One of the problems we are having in this discussion is the inter-switching between hand and power sharpening as they are very different simply due to the speed of metal removal. If was going to sharpen on a belt sander then I would use very fine abrasives for the reason you noted because I would not want the rate of metal removal to be that high that one pass would be all that is needed because you have no ability to correct a mistake, no ability to tune depth of cut, etc. . But I am speaking of hand sharpening, again just look at the title of this thread, it is above abrasives which are applied to a substrate to make a pseudo-stone for hand sharpening.

Yes i get that. To measure effects like temp ect i have to use stable processes like a turning wheel with abrasives, fixed speed and pressure though. Hand sharpening has to many different factors, speed, pressure ect to make adequate measurements. In the sample i gave we used a 120 mm diameter wheel with 300 rpm. which makes ca 180 cm/s
Hand sharpening is slower i think, but we would need an estimation from the average speed and pressure used with hand sharpening to make sensible comments.


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This tends to be mainly dominant on the finer stones and there are a few things which seem obvious here, for one just look at it on a percentage scale if you look at things like :

-grit presentation
-depth of bond
-size variance

If these things can produce a random influence on the order of 1-5 microns then on the very coarse stones they would produce a minor percentage effect so the consistency is going to be very high, however if the scratch pattern is supposed to be on the order of 1-5 microns then these types of variances can be on the order of the scratch pattern themselves.

The other thing which seems likely to be is that people are going to be far more sensitive to even seeing scratch difference when the polish gets very fine because usually :

-their sharpness tolerances are higher
-angles are lower and edges are thinner (amplifying the effects)

Yes, obviously you will notice the scratches on a polished surface sooner than on a courser surface. I can imagine the latter case is not so important for the user, and if you take this coarse surface as a end finish you probably don't care at all.

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Before I bought the new series of fine diamond abrasives then I did some net-scans and the reports are very inconsistent with some people reporting that the 1200 DMT was perfectly fine but other reports of noting that it was not, and some of them noted it could be improved with ceramic lapping and some noted it could not. Again the big issue here is are you seeing differences in the stones or just difference in the ability of people to see differences in the stones?

IMO about all the diamond stones have this effect more or less. Only the big window in sizes with the cheaper material will cause it. The only way to prevent it is to take care that no particles bigger then X are in the mix. Apart from that there always will be a observer difference which make things not easier. The latter factor could be taken out by magnification and measuring.

I found out that in the metal plates, i mean the galvanized types the particles actually stick out further than in other methodes, and being hold firmer by the nickel layer. That might be one of the problems. This might indicate that with a given window in particle size the metal plates have a bigger difference in hight of the particles than other matrixes. If so the effect in diamond waterstones should be much less than in metal plates.

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There is lots of data available on that both from Ken who had it measured directly, as well from those who have used it, you can find both commentary and high resolution pictures. Note however they are very expensive, they are basically sandpaper but they cost as much as the DMT plates and he will be open about the fact that edge-leading strokes can damage them.

I found several suppliers here that sell diamond flexible metal sheets, diamond sandpaper sheets and diamond PET foil. I will find out which particle size and price they have.

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In regards to the downsides, again this thread is about hand-honing compounds and while it is known that Diamond has problems with grinding ferrous materials at high speeds care needs to be taking to interjecting that into a discussion because the issues are not issues in hand honing.

There is to little fact material to make a sensible statement. We know that with high and moderate speeds diamond will do less good in carbon containing steel than CBN and a few other materials. Nobody measured lower speeds because the specific particles all have a minimum cutting speed. It is likely that the effect gets less with a lower speed and less pressure. But to say that there is no effect at all with hand sharpening is one step to far for me. If you try to measure the hand sharpening speed from yourself and a few others, we make an average and i can try to do a measurement. imo hand sharpening can cause overheating from the apex and there is definitive a difference in heating up between diamond and other abrasives.

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As for diamond vs cbn, I don't think anyone here wants diamond stones for the sake of diamonds, it is simply the case that it is trivial to get diamond plates and they have many advantages :

-come flat
-require only a little water
-are available in xx-c to xx-f grits
-not expensive
-can cut even the hardest and high alloy of steels
-can even cut ceramic and carbide tools
-are available in various shapes, rods, files
-can be used to lap other stones, including solid ceramic plates

Now if CBN hones are available then in what way are they going to be superior exactly and again we are talking about hand honing so the problems that diamond has an an abrasive are not limitations for that. Now can you get a CBN product which is :

-as flat
-similar in grit range, cutting speed

and is more consistent in scratch pattern. Then it is likely that you could make significant inroads into the diamond plate/file market. But marketing is going to be problematic outside of a small few people who know what CBN is because you are selling a softer/cheaper abrasive, that is how it is going to be perceived.

Well, the answer to that is yes;

- Flatness is a matter of lapping and can be done easily,
- Require little water is a matrix issue and easily solved,
- Available in any grit you ever dreamed of,
- Price will be depending on the quality and can be cheaper and more expensive than diamond,
- Can cut even the hardest and high alloy of steels
- Can even cut ceramic and carbide tools
- Can be made in any shape you could ever imagine,
- Can be used to lap other stones, including solid ceramic plates


There are a few misconceptions about diamond and CBN and i feel this is a good moment to clarify a few things;
(I'll do anything to prevent the English course)
So, there we go:

1- Diamond is not the hardest material we know. There are several other ones that are even harder, including a Boron variant: Wurtzite boron nitride.
Other ones are Lonsdaelite, (both natural) Beta Carbon Nitride β-C3N4, (That one is up to 1,5 times diamond hardness) Fullerite C60, Rhenium diboride, Aggregated carbon nanorod (Which is not diamond because of a different atomic binding) and a few other ones with even nastier names.

2- The hardness of diamond is between 8 and 10 Mohs. It is not a fixed number but a range.

3- The hardness range of CBN is between 9 and 9,5

Note 1: That means if you use shitty diamond it could be actually softer than CBN.
Note 2: With CBN you can hone all other materials including diamond.
Note 3: There is no material you find in (Ceramic) stones or steels that is harder than CBN.

4- more important for grinding and honing than the hardness are factors as: shape, toughness, coating, pressure resistance, matrix material.

In general it is easier to program CBN for those factors than it is to do the same thing with diamond. Diamond is a bit more brittle and that makes it hard to predict when it is going to brake with a given shape. (More accurate; in diamond particles there is a bigger difference in these properties in one batch.) Something you need to have an even wear and cutting from the stone or particles on a metal plate.

Because these particles, diamond and CBN actually are designed to function in power grinding, not hand sharpening, (This has to do with the minimum cutting speed) you can imagine that the ideal properties for hand sharpening could be different. I want to do testing in this respect, and in matrix respect. Even a simple Phenolic matrix has many ways to influence the results in hardness, toughness and material adhesion. That is the Micro and Nano tribology chapter.


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But if you can get it then I would be interested in a few plates and I would imagine so would a few other people here so if you can make it happen just let me know. Even if it doesn't actually prove to be functionally superior I would be curious to know / experiment anyway.


The reason for me to make some stones and send them over to people is to get comments, critics about points to make them even better. As in second opinion or peer review. There are hundreds of ways you can influence all properties of a stone and i want to speed the process up a little.

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This should be obvious and clear, but i am saying it anyway: By no means i expect you, or other people to promote or advertise items just because i designed them. Not at this website not at other places. As with all the sending around that i do with items i design: No obligations involved. A mail or PM with comments, good or bad and why, is all i would ask for and appreciate. I need that feedback to improve designs and skip the weeaboo that every designer has.
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Ok, i yell when i have something to test. I can send a package up to 30 kilo around the world for 35 euro or something like that so i will fill up the extra space with original Dutch building bricks so you can test those as well for sharpening.