CPM 15v Manix 2

[pleadnotguilty]

Excellent info, thx

[NCJohn62]

Thank you Shawn for such an expansive reply. At a time when diamond-based sharpening systems are becoming more accessible to even the most casual knife user information like this will help those who want to take the next step to truly high performance steels and sharpening.

[Librarian]

HI, Deadboxhero.
I would like to discuss the following statements of yours

As for when is the exact amount that you absolutely, positively, always need diamond the most commonly held belief was if the steel has 4% wt Vanadium alloy in its chemistry then you need diamond.

I don't understand why silicon carbide abrasive is not considered?
Silicon carbide sharpens with high-vanadium steels no worse than diamond.
I would even say faster. Silicon carbide grains are softer than diamond. Silicon carbide water stones are constantly updated during operation, the new sharp grain perfectly cuts any steel. The concentration of abrasive in the stones is very high. It's like in a fight, 5 weak people will defeat one strong, because there are simply more of them. When sharpening tools with a large contact area, silicon carbide waterstones work much faster than bonded diamonds.

As you may know, deeper scratches from the cheaper electroplated stones can mean bigger stress risers which can reduce edge stability and those scratches are more difficult to remove with higher grit.

If the scratches are so deep, then why not use stones with a fine grain size?
If a plated diamond works too rough, why not take another plated diamond with only fine grit? The number of grit indicated on the stone is only the size of the grain. The depth of cut of the metal also depends on the distance between the grains, the immersion of the stone, forces of pressure on the stone and so on.
So, it seems to me that this argument of yours cannot be written in the pluses of bonded stones

As an example with

A 400 grit atoma diamond and a 400grit metallic bonded Poltava will leave completely different surface roughnesses, the deeper scratches from the atoma will make the edge less stable and more prone to damage then the smoother scratches from the bonded stone at the same size grit

The bonded stones do cost more but they last longer and the performance of the end result is better.

I do not agree that one of these stones is better or worse. These are different stones and work differently. It is necessary to use the stone that is needed at the right stage.
It's like comparing a 400 grit stone to a 1000 grit stone and saying that - a 1000 grit stone is better than a 400 grit stone because it works more gently and finely, leaving less deep scratches.

[desmodue]

So, I can put an edge on a Maxamet blade with marshmallows if I use enough of them?

[aaronkb]

So, I can put an edge on a Maxamet blade with marshmallows if I use enough of them?

I’ve personally done it, are you gonna call me a liar?

[legOFwhat?]

So, I can put an edge on a Maxamet blade with marshmallows if I use enough of them?

I’ve personally done it, are you gonna call me a liar?

Good way of getting a nice sticky edge!

[crazywednesday]

So, I can put an edge on a Maxamet blade with marshmallows if I use enough of them?

I’ve personally done it, are you gonna call me a liar?

Good way of getting a nice sticky edge!

I'm easily entertained.

[olywa]

Wait, did you use coarse marshmallows?

[JRinFL]

Mini marshmallows for a finer finish.

[aaronkb]

Just gotta be careful of the burnt edges if you leave it in too long

[WilliamMunny]

Also forget the mineral oil for rust... just use honey... helps make the edge even stickier.

[mpc2]

Deadboxhero himself might not answer to Librarian´s post, probably he already has answered to similar arguments somewhere else and is very busy. But I find Librarian´s points interesting and not straighforward to dismiss or "debunk" . If what he wrote is so dumb, why don´t you write a quick response showing why he is wrong?

[WilliamMunny]

Deadboxhero himself might not answer to Librarian´s post, probably he already has answered to similar arguments somewhere else and is very busy. But I find Librarian´s points interesting and not straighforward to dismiss or "debunk" . If what he wrote is so dumb, why don´t you write a quick response showing why he is wrong?

No expert here but the one advantage of a bonded stone is that the diamond is throughout the material. So as the bonded stone breaks down it will reveal new diamonds. The electroplated diamond plates just have the diamonds of the surface that will slowly be taken off with use. Currently I use electroplated diamond plates to sharpen.

But yes, I would also like to hear more about a bonded diamond stove vs a finer grit diamond plate. The finer grit diamond plate should make smaller scratches in the steel but maybe still not small enough vs a bonded stone?

[Josh Crutchley]

snip<

I don't understand why silicon carbide abrasive is not considered?

snip<

I do not agree that one of these stones is better or worse. These are different stones and work differently. It is necessary to use the stone that is needed at the right stage.

The hardest silicon carbide is 2400-2600 vickers but sharpening stones could use softer grades. Where as vanadium carbide is 2800-3000 vickers. CBN comes close to 5000 vickers. So with those values known why choose SiC over diamond and cBN?

I haven't noticed much difference in the final apex when comparing plates to bonded stones. I do believe bonded stones are better over time though. They have the ability to be dressed to expose new abrasive. The plated stones eventually smooth out because it's only held together by soft nickel. So either the diamonds get ripped off or fracture until the surface is smooth.

[Librarian]

The hardest silicon carbide is 2400-2600 vickers but sharpening stones could use softer grades. Where as vanadium carbide is 2800-3000 vickers. CBN comes close to 5000 vickers. So with those values known why choose SiC over diamond and cBN?

A few of my theses.
1. The hardness of silicon carbide is sufficient for comfortable and rapid processing of high vanadium steels. This is the main thing. For a regular cycling ride, it is not necessary to buy a bicycle with a carbon frame. This is a matter of the necessary minimum.

2. In addition to the hardness of abrasive, the shape of the abrasive is important. No matter how hard the abrasive is if it has become round, without sharp parts, it will not work.Compare the work on the wood of the file and the smooth metal plate of the same hardness.

The abrasive cuts the metal not with hardness, but the shape of the grain. The stronger the abrasive, usually, the longer the grain retains its shape.
The abrasive is blunting during work.
Diamond powder is much more expensive than silicon carbide. Silicon carbide should not be used economically. When silicon carbide grains are just starting to smooth them out and work with new sharp grains.
Why work with one blunt knife if you have 10 spare ones? You will replace the blunt blade when it becomes uncomfortable.

3. You drag not just a type of abrasive, but a stone. A stone is a combination of the amount of abrasive and the speed of its update.
I will also remind you that it is not worth forgetting about the concentration of an abrasive in the stones.

There are many subtleties and other things. And we must consider specific stones.
I wanted to show that diamond is not a single abrasive that is suitable for sharpening high vanadium steels.

Just the original statement seemed to me too categorical, so I considered it an alternative to offer.

I haven't noticed much difference in the final apex when comparing plates to bonded stones. I do believe bonded stones are better over time though. They have the ability to be dressed to expose new abrasive. The plated stones eventually smooth out because it's only held together by soft nickel. So either the diamonds get ripped off or fracture until the
surface is smooth.

No expert here but the one advantage of a bonded stone is that the diamond is throughout the material. So as the bonded stone breaks down it will reveal new diamonds. The electroplated diamond plates just have the diamonds of the surface that will slowly be taken off with use. Currently I use electroplated diamond plates to sharpen.

I would like to answer at the same time.
Do not forget what you pay for it. bonded stone are much more expensive than galvanic stones. The resource of the plate with galvanic coating is very large, when they stop working, you can just buy a new one. Analogy: Imagine that 5 (figure from the head, you need to watch prices, approximately) of galvanic stones cost like one bonded stone.
It's a matter of taste.
You can only say that this one cannot be called a plus or minus.

For example, naniwa superstone are sold with a thickness of 10 mm and 20 mm. If I need a stone of 8000 grit, a stone with a 10 mm thick will be enough for me not only for me, but also to my grandchildren. Why do I need a 20 mm stone?
How often do you change the plates of diamonds on the galvanic plates? I think they are not too often.
Again, this is an economic factor.

[Librarian]

As a clear example of the effectiveness of silicon carbide stones. This is a blade made of steel s60v with a hardness of 61HRc
I argue (within a reasonable time) that such work cannot be done on a diamond, you simply cannot create such pressure on the blade that the diamond would begin to cut steel (the contact area is large, the pressure is scarce). The blade will simply slide over the stone.
And even if you can push that hard, you won't be able to maintain that pressure for long.
But the soft water stone Suehiro GC-10 220 grit copes with this by updating a new and very sharp abrasive.

[dlum1]

A few of my theses.
1. The hardness of silicon carbide is sufficient for comfortable and rapid processing of high vanadium steels. This is the main thing. For a regular cycling ride, it is not necessary to buy a bicycle with a carbon frame. This is a matter of the necessary minimum.

2. In addition to the hardness of abrasive, the shape of the abrasive is important. No matter how hard the abrasive is if it has become round, without sharp parts, it will not work.Compare the work on the wood of the file and the smooth metal plate of the same hardness.

Something doesn't sound right here. You're forgetting pressure. With it, a round object can definitely cut. Press a metal ball bearing against a sheet of drywall and drag it. It can definitely leave a gouge mark. With such a small surface area near the edge of a blade, a light force can result in some significant pressure. But you're right in that silicon carbide is sufficient to sharpen high-vanadium steels. It's just that it might not do it optimally because the silicon carbide will not cut the vanadium carbides. Rather, it'll cut the metal surrounding the carbides, and at some point the carbides will either be extracted or break from the stress.

Check out the science of sharp for some interesting images of what happens when the abrasive is softer than the carbides. I think Shawn was merely pointing out diamond will likely have better results -- not just in sharpening the edge but in edge longevity. I would assume this is because the carbides would also be cut to follow the edge rather than being haphazardly hanging out. Being a professional knife sharpener, I'm sure BBB has done both. I'd be curious to hear his experience in the matter. I'm also curious to know, have you tried both? I've done both with s110v. However, I don't use my knives enough in a controlled environment to say with statistical significance that my BDN stones result in a superior edge. I have noticed better edge performance, but that could be because the factory edge is now gone.
Thoughts?

[dlum1]

Just saw your next post. The contact area is actually rather small at the microscopic level. The overall force pressing the knife into the abrasive will be divided by a fraction of the contact area because the surface of each surface is rather rough at the microscopic level. This is why very light pressure with something like s110v against diamond stones will still leave scratches in the metal. As an aside, this is also how I discovered that trying to clean zdp-189 with a green brillo scour pad is a bad idea -- scratched the living daylight out of the satin blade.

[Bolster]

...trying to clean zdp-189 with a green brillo scour pad is a bad idea -- scratched the living daylight out of the satin blade.

Wow, I'd have never guessed that. Interesting!

[Librarian]

t's just that it might not do it optimally because the silicon carbide will not cut the vanadium carbides. Rather, it'll cut the metal surrounding the carbides, and at some point the carbides will either be extracted or break from the stress.

Whether it's optimal or not, I don't know. These are speculations and a big scientific question. It is necessary to read specialized literature and provide information. Within the framework of this forum, we will not find an answer to it.
What is known for certain is that throughout the 20th century, people used silicon carbide to wheelbarrow industrial tools, including high speed steel.

Check out the science of sharp for some interesting images of what happens when the abrasive is softer than the carbides.

I don't remember that silicon carbide was mentioned there. I remember the result of shapton on maxamet, but this is aluminum oxide.
The work of an abrash is more complex than just comparing hardness.

I think Shawn was merely pointing out diamond will likely have better results -- not just in sharpening the edge but in edge longevity.

This is too complicated work to do it somehow with statistics. I don't think that it will be possible to show it somehow.

I easily sharpen my knives from k390, s90v, zdp-189 on silicon carbide. I am satisfied with the result and speed of work.