knives, whet stones, sharpening - an update and some questions

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Chris, I'm now stuck with this image in my head of someone in a straight jacket with a whet stone attached to his/her tongue!!!!!

Will give it a try though when no-one is watching
 
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Chris, I'm now stuck with this image in my head of someone in a straight jacket with a whet stone attached to his/her tongue!!!!!

Will give it a try though when no-one is watching
Hey, I'm just sayin'... /img/vbsmilies/smilies/lever.gif
 
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Joined Jan 8, 2010
Not (yet) in that jacket and managed to give the stone-licking exercise a try.

It didn't stick!

Only needs a couple of minutes to get thoroughly wet.

Proceeded in sharpening the gyuto JCK carbonext. It was fairly sharp to start of with, but since the FKH petty was sharper, I figured it was worth a try.

I used the magic marker trick.

Sharpening on the 1000 grit side was fast and pretty straight forward. A bigger stone is definitely a big plus!

After deburring etc I went to the 4000 side. This took quite a bit longer, but no real problems.

Deburred and cleaned the knife. Cut my thumb and I wasn't even really toughing the edge (just trying to clean off the magic marker line).

The knife is very sharp (according to my gradations and sharper than any knife I've ever held)

It's now sharper than the FKH petty, so that's my next job.

Man, I'm enjoying this.

Very satisfying
 
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Aha, so you just succeeded in sharpening your first virgin knife. It's indeed quite satisfying.

Maybe something on higher grit stones. Your 4k stone serves to polish the edge after sharpening on a rougher stone. You don't need to use a lot of downforce to polish, just a bit more time. That also implies there will be very few burr.

Cutting yourself is part of the experience. You will also enjoy rubbing some skin from your fingers on rough stones.

I found this picture of a "big" stone. Seems the guy never spoke again since he licked it, not to mention his wife's disappointment.

 
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Most of these synthetic composite stones need to be soaked. How long? At least until they are saturated with water, which means as long as tiny airbubbles escape from the stones when submerged. Could be 1 minute, could be 5 minutes or longer. A brandnew dry stone always takes a minute longer. I never soak longer than 3-4 minutes.

Also, more important, keep the stones very wet on the surface when sharpening by plunging them from time to time into the water, and I wipe (just use a hand to rub the surface) and rinse them regularly under water or under a running watertap to get rid of metalparticles during the sharpening.

I was told by, can't-remember-whom, that I shouldn't wash the 'mud' when sharpening on the water stone for it helps to sharpen??  I don't use this water stone very often.  I picked this stone and yanagiba in Korea for the purpose of practicing caring and sharpening single bevel knives before I invest in better quality.  Has anyone heard anything about this??
 
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Water stones work differently from oil stones. 

Oil stones are created -- naturally or artificially -- with the abrasives baked or compressed into very hard binder materials.  The binders aren't soluble and are difficult to wear away, so the abrasive stays on the surface of the stone.  If swarf is left on the stone, it can either clog the stone or crawl up the sides of the knife and scratch it.  Consequently, it's important to keep the stone as free from swarf as possible.  In fact, that's the purpose of using oil -- to float the swarf.   

Water stones are different.  The binders are both softer and soluble.  The binder and abrasive are lifted from the stone by the action of the knife and create a slurry which is often referred to as "mud."  Because fresh abrasive is constantly coming up, water stones tend to work faster than oil stones.  Anyway, it is the abrasive particles in the mud which do (and should do) most of the sharpening, not the abrasives stuck on the surface of the stone.

As a general rule one doesn't want to rinse the mud away frequently.  Only when it becomes completely loaded up with swarf.  As the abrasives in the mud break down, they make the stone act as though it were a finer grit.  In effect, it's like working with two stones:  The first stone fast, and the second one fine -- perfect! 

Some stones though DO work better with lots of rinsing.  It's easy enough to find out what works best with yours.  Just try it both ways.

Hope this helps,

BDL
 
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BDL;"...Some stones though DO work better with lots of rinsing.  It's easy enough to find out what works best with yours.  Just try it both ways..."

Even better, some stones produce different results when used with "mud" vs "naked".

A great example are my natural coticules, polishing stones estimated 6-8k. Normally they are used after having rubbed some mud out of the stones using a small coticule. This will produce a very nice almost mat finish.

Use the same stone without mud and the polishing will result in a mirrorshiny result, but the feeling while polishing is totally different. The mud works smooth and slows down the movements on the stones. Working "naked" feels like gliding over a very tough surface. I use this method for the last polishing strokes that are performed without pressure on the knife.

I always rinse the moment I hear scratching sounds that are probably caused from metalparticles on the stone,could be very tiny bits of burr detaching from the blade?
 
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A minor note: many high-end stone professionals in Japan, using seriously high-end natural stones, do not get rid of swarf no matter how much there might be. The mud is so important to that sharpening process that they'd rather have mud corrupted by swarf than low mud.

Which just leads back to BDL's point. Try it with minimal mud -- rinsing often; try it again with mud until it's fairly black; and try it yet again allowing whatever happens to happen and build up as much mud as will build. See what works best for your stone. With synthetics, on the whole you can work out what's best for a given stone and then every one you buy will be the same. With naturals, you have to learn how the stone works best, stone by stone. If you don't think that sounds like fun, don't even think about touching naturals!
 
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Which just leads back to BDL's point. Try it with minimal mud -- rinsing often; try it again with mud until it's fairly black; and try it yet again allowing whatever happens to happen and build up as much mud as will build. See what works best for your stone.
You all continue to keep my mind busy every time I visit this site :)

Am I reading this correctly that it may actually be better not only to sharpen in the mud that develops from contact between the knife and stone, but also the mud that is full of steel that has been removed from the blade can also be a benefit?

OK on certain stones that can change, but never even considered there would be a positive once the mud was full of steel etc.

I guess this idea of leaving all the mud and swarf on the stone would be something I would need to work at since I have been trying to use the mud as much as possible, and then once it was full of steel particles I would just utilize the entire length of the stone for grinding the edge, and that would normally push or pull the mud off the end of the stone (and all the steel with it as well)

Since this was never really an issue with the norton I used for so many years (I just washed it all off of the stone with more water to clear it up) it is something that takes a little getting used to. Plus the fact that some (I see the carter vids showing to make full use of the entire stone to reduce dishing and speed things up a bit) seem to just push the mud off the stone during the normal strokes of the blade only makes it more interesting/confusing.

Please let me know if I got this right as I am sure I am not the only one thinking WTF and that depending on the stone it may be better to fully utilize the entire length, others may do better with some mud, and others yet may perform best with trying to actually sharpen through the steel filled swarf?
 
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Joined Dec 3, 2010
Not (yet) in that jacket and managed to give the stone-licking exercise a try.

It didn't stick!

Only needs a couple of minutes to get thoroughly wet.

Proceeded in sharpening the gyuto JCK carbonext. It was fairly sharp to start of with, but since the FKH petty was sharper, I figured it was worth a try.

I used the magic marker trick.

Sharpening on the 1000 grit side was fast and pretty straight forward. A bigger stone is definitely a big plus!

After deburring etc I went to the 4000 side. This took quite a bit longer, but no real problems.

Deburred and cleaned the knife. Cut my thumb and I wasn't even really toughing the edge (just trying to clean off the magic marker line).

The knife is very sharp (according to my gradations and sharper than any knife I've ever held)

It's now sharper than the FKH petty, so that's my next job.

Man, I'm enjoying this.

Very satisfying
Butzy that almost mirrors my experience. I would find after spending a little extra time attempting to improve the edge I thought was not as sharp as the other that it became even sharper than the previously sharper knife, and then that got me to pull out the stones again and try to improve on the other that was then seemingly dull compared to the newly sharper knife.

I dont think I am going to be licking the stones anytime soon (not only am I feeling nuts enough with all of this, but I have this vision of Ralphie from a Christmas story with is tongue stuck to the flag pole  lol)  but do have more than one of those nice fine cuts in my fingers from attempting to measure sharpness or just putting a little too much pressure on the edge.

One thing that caught my attention was that you were having to remove the marker from the edge. Was that because you made the line too thick or just did not remove it all when sharpening?

I ask because if you put the line on the edge correctly I think you want to be grinding it off completely because otherwise your changing the bevel. I have more than once picked up a magnifier to check the accuracy of the marker on the edge to make sure it was right because you can (and I have before) find that the width of the marker line is actually wider than you wanted to thought and you end up trying to remove material in areas you may not really wanted to, or even vice-versa etc.

Also great to hear your finding your way to improved sharpness and improving upon your previous sessions as that is a great feeling, big motivator, and I believe in more ways than one what it's all about!
 
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@Lenny

I put quite a  wide line on the edge, probably about 1/2 to 3/4 of a cm wide or so.

This way I can see exactly how much (how wide) I've been grinding.

So far I've been sticking to the factory settings. Now I'll just have to see how long the knives stay sharp etc.

As a precaution, I've put my knives in my room for the time being as I'm staying with my dad. He's used to sharp knives and he knows what I'm up to, but if someone else picks those knives up.......

Just don't wanna have to rush of to the hospital with someone's fingertip in a plastic bag
 
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Reading this post makes me want to take out all my knives and go nuts!

Checking with magnifier is a great idea..

I've heard Masaharu Morimoto runs his knife across his thumb nail to check the sharpness.  I don't think my knives will pass.
 
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Originally Posted by LennyD  

Am I reading this correctly that it may actually be better not only to sharpen in the mud that develops from contact between the knife and stone, but also the mud that is full of steel that has been removed from the blade can also be a benefit?
I guess this idea of leaving all the mud and swarf on the stone would be something I would need to work at since I have been trying to use the mud as much as possible, and then once it was full of steel particles I would just utilize the entire length of the stone for grinding the edge, and that would normally push or pull the mud off the end of the stone (and all the steel with it as well)Please let me know if I got this right as I am sure I am not the only one thinking WTF and that depending on the stone it may be better to fully utilize the entire length, others may do better with some mud, and others yet may perform best with trying to actually sharpen through the steel filled swarf?
Yes, that's correct. It is indeed confusing.

What you're currently doing -- using the mud until it fills with swarf -- is by far the most usual approach with synthetic stones. People who don't like mud buy harder stones and don't worry about this. The only person I know of who absolutely insists on keeping the mud even with swarf is using high-end natural stones and is a world-class expert sharpener and stone appraiser working in Kyoto. I do not know his opinion on this matter as regards synthetics.

My feeling is that you simply have to figure out what works best for you, with what stones, with what knives. There are no absolutes here that I know of. My general opinion, however, is that there is something of a spectrum, based on four factors: bevel size, steel quality, stone fineness, stone quality.

Thus if you are sharpening a gyuto, with relatively coarse steel, on a medium-grit stone, and it's a medium-quality synthetic (e.g. a King), you would probably be best rinsing often. If you are sharpening an usuba, of extremely fine steel, on a very fine polishing stone, and it's a high-grade natural, you would rinse rarely if ever.

But I think that spectrum, even if I have defined it reasonably accurately, admits of enormous variation, so try things and see what works best for you with your knives.
 
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@Lenny

I put quite a  wide line on the edge, probably about 1/2 to 3/4 of a cm wide or so.

This way I can see exactly how much (how wide) I've been grinding.

So far I've been sticking to the factory settings. Now I'll just have to see how long the knives stay sharp etc.

As a precaution, I've put my knives in my room for the time being as I'm staying with my dad. He's used to sharp knives and he knows what I'm up to, but if someone else picks those knives up.......

Just don't wanna have to rush of to the hospital with someone's fingertip in a plastic bag

I usually try to only mark the edge as wide as it actually is with the marker. That way if it is all ground away I know I got the angle the same as OEM, and if it is still showing in spots I know where  I am missing and if the blade is being held too high or low etc.

It is funny because it can actually be a little tough to hold the maker evenly against the edge without making the mark wider or thinner than the edge itself.

Now finger tips in  a plastic bag are a real concern, and hope it does not come to that ooooouch!

I am no pro at this either and I figure as long as you can get sharper knives or better results as time goes on then your doing something right, but know very well that those very same improvements while a motivator are also evidence that we all were not really doing it right previously either lol.
 
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Yes, that's correct. It is indeed confusing.

What you're currently doing -- using the mud until it fills with swarf -- is by far the most usual approach with synthetic stones. People who don't like mud buy harder stones and don't worry about this. The only person I know of who absolutely insists on keeping the mud even with swarf is using high-end natural stones and is a world-class expert sharpener and stone appraiser working in Kyoto. I do not know his opinion on this matter as regards synthetics.

My feeling is that you simply have to figure out what works best for you, with what stones, with what knives. There are no absolutes here that I know of. My general opinion, however, is that there is something of a spectrum, based on four factors: bevel size, steel quality, stone fineness, stone quality.

Thus if you are sharpening a gyuto, with relatively coarse steel, on a medium-grit stone, and it's a medium-quality synthetic (e.g. a King), you would probably be best rinsing often. If you are sharpening an usuba, of extremely fine steel, on a very fine polishing stone, and it's a high-grade natural, you would rinse rarely if ever.

But I think that spectrum, even if I have defined it reasonably accurately, admits of enormous variation, so try things and see what works best for you with your knives.
Chris,

Well most of this has been confusing, but I think that is also part of making it interesting as well :)

Since I am still using a combination of very different stones and silicon carbide papers I am getting varying amounts of mud and even none.

The glass stone though very hard seems to produce a certain amount of mud, but since it is much less than the arashiyama I had not given it much thought to "working it", but on the Arashiyama which is a 6k I have found I was looking to work the mud more even when not thinking about it.

I think what is true about the last sentence of your post is also what is where the confusion comes from for a newbie as without more experience it is really hard to know if what you think is best actually is.

Have to admit that it does seem to become more obvious as you get more time on the stones similar to how angle, sharpness, and pressure do so I guess it is just another part of the whetstone learning curve.
 
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A glass-stone is a great example of something for which mud is a null.  An Arashiyama is all about mud. You have pretty much the extremes of the equation, and I suspect this is causing you some of these problems.

Some people like mud, some people hate it. People who hate mud gravitate toward the glass-stone end of things. People who like mud gravitate toward the Arashiyama end of things. Kings are dead in the middle: they produce a little mud, and it's a good thing, but it's neither so much that haters get into the hating, nor so little that the lovers can't fall in love. That's why Kings are so great --- and so sort of neutral.

I think you need to see what works for you. It turns out, I love mud, but the Arashiyama drives me bonkers because it just doesn't want to get its act together without ten years of soaking. What I want is a muddy stone that soaks up in 30 minutes. On the other hand, a really slick, non-muddy stone bugs me, because I can't tell what I'm doing without feeling the blade constantly. This is why Choceras are good for me: I get lots of feedback, I know what's happening, mud is present, and they don't soak too long. But they cost a fortune, and frankly if I hadn't bought them for a ridiculous fraction of what they cost in the US, I'd probably resent them.

Fortunately, stones don't last forever. When they start wearing down to nothing, ask yourself which you'll really miss. If it's the Arashiyama, turns out you like mud. If it's the GS, you don't like mud. Buy your next stones on that basis. In the meantime, these stones are all good, so don't sweat it: you're learning to sharpen very well on excellent stones, so if you develop bad habits like mine, it's your own darn fault (as it is mine).
 
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