Whetstone advice wanted am I crazy?
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You know, as a side remark, something about rounded edges kind of confuses me. How is it possible to really produce a rounded edge with a stone? As long as you never raise your angle more than 20 degrees on each side, and you hit every part of the edge at some point, you are guaranteed to have an at most 40 degree apex at every point along the edge. I mean, maybe slurry or severely nonflat stones can cause problems and make the edge more rounded, or metal can build up at the edge in the form of a burr and you can not remove it correctly. I just see people (not @M1k3) blaming a wobbly hand for a rounded edge, and I don’t see how that’s related. In some sense, the above is why freehand sharpening works at all, and why we don’t all need to use jigs. I mean, wobbling is bad for other reasons, since you want the geometry behind the edge to be consistent, and you don’t want to be hitting the edge more in one part of the blade than another, f’ing up the profile, and it probably makes sharpening more efficient if you don’t wobble, but I don’t think it causes rounded edges. Or maybe there’s some other relationship I’m missing.
KingShapton
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I suspect your purple welsh slate is a purple Llyn Melynllyn ?!
In that case I know your problem, I own this stone myself. Do you have a nagura for this stone? Alternatively, you can create a bit of slurry / mud on the stone with a diamond plate.
If it's a purple llyn melynllyn then only use the stone with slurry / mud. Without it, the stone polishes too much and creates a sharpness without bite
Sharpened both my main blades up doing what you said Ian and got both done in about 25 minutes 
the tips never been better even when new made me notice there was a bit of a bulge that needed ground down a bit... Both now going through a carrot at just knife weight and a push forward did notice though the blue #1 is a damn sight smoother and sharper than the harder thinner sg2 
the tips never been better even when new made me notice there was a bit of a bulge that needed ground down a bit... Both now going through a carrot at just knife weight and a push forward did notice though the blue #1 is a damn sight smoother and sharper than the harder thinner sg2 That's exactly the stone and yep you're on the money the knife wont go through a tomato if I go real well on it but if I cut though carrots and that then it'll go through the tomato definitely a balance and yep I've got the nagura with it.. Never thought to make the slurry I was always told it would give a worse edge
or maybe I am a mess of house hunting anxiety and I’m expressing it by being anal about terminology on the internet.
Even sharpening on a sphere wouldn't have a chance to round the edge. Either the edge makes contact or it doesn't - and at that, either a long consistent segment, or just a short one, or just a tiny point along, is the difference between a flat surface and a "dished" or uneven one - or a stupidly rounded one.
But that's considering even angle. If someone has really really poor angle consistency, then I guess theoretically he could round the edge by alternating enough between a lot of closely grouped angles...
Just to feed the technical but futile discussion.
I guess "plateau'd" is something more likely to happen - apex killed by a "slip" to an obtuse angle, apex never formed because the angle is too low.
But that's considering even angle. If someone has really really poor angle consistency, then I guess theoretically he could round the edge by alternating enough between a lot of closely grouped angles...
Just to feed the technical but futile discussion.
I guess "plateau'd" is something more likely to happen - apex killed by a "slip" to an obtuse angle, apex never formed because the angle is too low.
My “rounded” are generally a result of me interrupting the process halfway through and restarting at a new, slightly different angle. You can easily see it on the low grits but after polishing you get rounded reflections instead of straight cut ones. This also happens when I change stones and am so eager to hit the apex that I subconsciously increase the angle.
Tldr - crappy angle control “rounds” my secondary bevels.
Tldr - crappy angle control “rounds” my secondary bevels.
Bigbbaillie
Well-Known Member
If you are spending 30-45 minutes to sharpen a knife that is already sharp enough to cut newspaper you should definitely buy a 500-1000 grit stone. Honestly you are just wasting your time if you don't.
I can breadknife a knife on a 120 grit stone until its completely dull (won't cut paper) and bring it back to razor sharp easily within 5-10 minutes (generous estimate) using a sg500 or sg1000 paired with a ~2k or higher finishing stone. Think about how much time you will save over the years for an investment of only $40-$50.
You gotta be kidding yourself if you think you should be buying a Denka without having a lower mid-grit stone already. Time is way more valuable and important than shiny new knives. That's my opinion at least.
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For "rounded edges" from a "wobbly hand", I get it the idea. Basically meaning that if you don't hold a pretty consistent angle you can round over the edge. It would different all along the edge and on both sides though so not sure "rounded" is the best descriptor but I get it.
I generally say one can crush the apex if they're inconsistent. It doesn't take much and the thinner and finer the edge, the more susceptible it will be. Crushing the apex I think is most likely to happen during the deburring strokes, especially edge leading.
Either that or you just flat don't achieve a proper apex along the entire blade due to the randomness of the "wobbly hand".
Counting strokes is pointless. If one wants to count thinning strokes to help symmetry, ok, but for edge sharpening it has no place and @ian 's explanation is excellent.
Time to sharpen... I've always struggled with this to some degree. There's so many factors at play. I will say, without a doubt, that the more time you spend on the stones, the more opportunity you have to screw things up. The goal should always be the minimum time necessary to achieve proper apexing. I think time spent sharpening should be a gauge and used with other information. I again agree with Ian here in saying 30-35 min's for edge maintenance is too much. I'm not as much a fan of saying I can take a spoon to shaving sharp in five minutes type thing. I mean I get it, I understand it is presented for context, I just get wishy washy on it.
I think it can cause undo stress for the sharpener trying to be open and evaluate their technique and learn. The, "holy crap this is taking me 15mins and people say that's waaaay too long" type deal. I can say in full disclosure, there are instances when I can't do it. Things won't gel for whatever reasons and I find myself just being off. When it happens, I need to assess things. Is it just a spot? Am I rushing or not paying attention? Did I already crush my edge and need to regroup and maybe drop down? Am I flustered and just need to walk away and come back another day? Sometimes, I can just evaluate and get back to it and finish nicely. That may be 20 or even 30 min's. Other times, I can tell 5-10mns in that I just need to stop and come back later. But in all cases it isn't really the time so much as the effort.
I don't like to pay much attention to the clock any more. I just like the experience to tell me. I can tell when I've been going for a bit and things aren't working.
I know that's long-fingered and maybe semantics, I just hate to see folks setting time goals because they think that's a metric. Just focus on the edge. Let the edge guide you.
I generally say one can crush the apex if they're inconsistent. It doesn't take much and the thinner and finer the edge, the more susceptible it will be. Crushing the apex I think is most likely to happen during the deburring strokes, especially edge leading.
Either that or you just flat don't achieve a proper apex along the entire blade due to the randomness of the "wobbly hand".
Counting strokes is pointless. If one wants to count thinning strokes to help symmetry, ok, but for edge sharpening it has no place and @ian 's explanation is excellent.
Time to sharpen... I've always struggled with this to some degree. There's so many factors at play. I will say, without a doubt, that the more time you spend on the stones, the more opportunity you have to screw things up. The goal should always be the minimum time necessary to achieve proper apexing. I think time spent sharpening should be a gauge and used with other information. I again agree with Ian here in saying 30-35 min's for edge maintenance is too much. I'm not as much a fan of saying I can take a spoon to shaving sharp in five minutes type thing. I mean I get it, I understand it is presented for context, I just get wishy washy on it.
I think it can cause undo stress for the sharpener trying to be open and evaluate their technique and learn. The, "holy crap this is taking me 15mins and people say that's waaaay too long" type deal. I can say in full disclosure, there are instances when I can't do it. Things won't gel for whatever reasons and I find myself just being off. When it happens, I need to assess things. Is it just a spot? Am I rushing or not paying attention? Did I already crush my edge and need to regroup and maybe drop down? Am I flustered and just need to walk away and come back another day? Sometimes, I can just evaluate and get back to it and finish nicely. That may be 20 or even 30 min's. Other times, I can tell 5-10mns in that I just need to stop and come back later. But in all cases it isn't really the time so much as the effort.
I don't like to pay much attention to the clock any more. I just like the experience to tell me. I can tell when I've been going for a bit and things aren't working.
I know that's long-fingered and maybe semantics, I just hate to see folks setting time goals because they think that's a metric. Just focus on the edge. Let the edge guide you.
Thing is, you're not really rounding the actual apex by doing that, you're convexing behind the edge. As long as your angle never exceeds 20 degrees, say, you'll always have an acute apex (given that you do hit it at some point when you sharpen), it's just that the bevel behind it will be flat if your angle is constant vs convexed if you wobble. Anyway, that's at least the point I was making.
Ah. Got it this time. I wasn't considering the max angle.
Bear with me here... If the apex is at say 15 degrees and you wobble around from 15-20 there will be "rounded" spots though yeah? Wouldn't you be "rolling" the apex once you exceed that 15? Honestly not trying to argue semantics. I think it is interesting.
Corradobrit1
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Maybe time for one of these cheat gadgets
https://www.amazon.com/Naniwa-QX-00...ocphy=9026825&hvtargid=pla-368511221447&psc=1
https://www.amazon.com/Naniwa-QX-00...ocphy=9026825&hvtargid=pla-368511221447&psc=1
Heh, to roll or not to roll. That is.. no, wait, the question is what is to roll. Or rolling. Rolling rolling.
Idk what one wants to call it. You'd get an edge that's a little more acute some places, less acute other places. It's hurting my brain trying to figure out every way in which an edge could be suboptimal, and every way in which one could produce such an edge.
The illustrations I made here might help the conversation:
https://www.bladeforums.com/threads/easier-freehand-sharpening.1726451/
I think that you are right. I haven't rounded an edge on a stone in many years by basically following this logic. And I get pretty aggressive with the high angle passes on fine grit synthetic stones.
I have noticed what I would call "rounded edges" on softer stainless when I over do convexing on the 1X30 slack wheel. But that is a completely different ballgame when that thing is moving 1600 feet per second (edit: 1600 feet per minute). The apex just melts.
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Melts, and burns. I have such a hard time not burning edges on my 1x30. Basically have to do 1 second full blade passes in order to not overheat the edge.
Luftmensch
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Hehe... why place a limit in either direction? Model the sharpening angle as a stochastic variable under some distribution. Lets choose a Gaussian because they are 'friendly' and say the mean is 20 degrees with a standard deviation of 1.25 degrees. That means approximately 68% of the work is done within +/- one standard deviation (1.25 degrees) of the mean. And approximately 95% of the work is done within +/- two standard deviations of the mean (from 17.5 and 22.5 degrees). Some of that will be 'rounding' (high angles) and some of that will be 'thinning' (low angles).
The better you get at honing, the smaller your standard deviation!
I suppose that means you will be doing less 'rounding' and 'thinning'.... and more... 'sharpening'...
?
user 16756
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Hehe... why place a limit in either direction? Model the sharpening angle as a stochastic variable under some distribution. Lets choose a Gaussian because they are 'friendly' and say the mean is 20 degrees with a standard deviation of 1.25 degrees. That means approximately 68% of the work is done within +/- one standard deviation (1.25 degrees) of the mean. And approximately 95% of the work is done within +/- two standard deviations of the mean (from 17.5 and 22.5 degrees). Some of that will be 'rounding' (high angles) and some of that will be 'thinning' (low angles).
The better you get at honing, the smaller your standard deviation!
reviewer 2: paper does not cite A Guide to Modeling Freehand Sharpening Under Normal Atmospheric Conditions and is not novel research. Reject.
Another conversation about slate eh? Count me in!
Though I'm sure I've done it to a million knives I don't really know what a rolled edge is or feels like, but... I have certainly used slates that give the kind of edge described; they can excel at certain 'sharpness tests', and be pants at others.
The reason for this, I think, is because of its form, and formation (pic attached). When you sharpen on slate you are sharpening on quartz that has been flattened parallel to the layers of the slate during the metamorphic process. And flat quartz doesn't do a huge amount of cutting. You'd have thought you could get around this by cutting the face of a stone across layers, but often ime you can't do this. A lot of slate really is quite layered, and it'd chip and break up if you tried, it would also absorb a huge amount of water and feck up the stone.
The slates I've found that have the most cutting ability are ones in which you have the layers formed across the former bedding planes of the original mud. You're still sharpening on a single layer of slate, but across layers of the original deposits. A second pic attached, showing the wavy lines on the completely flat and dry surface of one of my stones, on the left. It has been flattened along a layer of slate, that was formed across the bedding planes.
But yeah - slates finish more refined than other stones of comparable grit ime. And I imagine the when you get to the mega-fine levels of some Welsh slates this is going to be really quite polished. Though as KS said - mud helps - release some of those bits of quartz and you're no longer sharpening just on flat stuff.
[This is all conjecture and extrapolation from what I've read and experienced. So may be wrong, and/or it may not apply to all slates.]
Though I'm sure I've done it to a million knives I don't really know what a rolled edge is or feels like, but... I have certainly used slates that give the kind of edge described; they can excel at certain 'sharpness tests', and be pants at others.
The reason for this, I think, is because of its form, and formation (pic attached). When you sharpen on slate you are sharpening on quartz that has been flattened parallel to the layers of the slate during the metamorphic process. And flat quartz doesn't do a huge amount of cutting. You'd have thought you could get around this by cutting the face of a stone across layers, but often ime you can't do this. A lot of slate really is quite layered, and it'd chip and break up if you tried, it would also absorb a huge amount of water and feck up the stone.
The slates I've found that have the most cutting ability are ones in which you have the layers formed across the former bedding planes of the original mud. You're still sharpening on a single layer of slate, but across layers of the original deposits. A second pic attached, showing the wavy lines on the completely flat and dry surface of one of my stones, on the left. It has been flattened along a layer of slate, that was formed across the bedding planes.
But yeah - slates finish more refined than other stones of comparable grit ime. And I imagine the when you get to the mega-fine levels of some Welsh slates this is going to be really quite polished. Though as KS said - mud helps - release some of those bits of quartz and you're no longer sharpening just on flat stuff.
[This is all conjecture and extrapolation from what I've read and experienced. So may be wrong, and/or it may not apply to all slates.]
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KingShapton
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Even if it's over the topic, the Dai's look very good!
Luftmensch
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<I just read the beginning of this thread in greater detail>
@ChefDan96,
There is no 'right' way to sharpen a knife. Many methods can get you the results you desire. That said, collective wisdom is a good shortcut for avoiding mistakes or unproductive behaviour.
I believe low-mid grits are indispensable in the kitchen and it is a good option to have proper low grit stones. In fact I will contend that if *I* had to choose only one stone it would probably be a low-mid grit like 800-1000. If I could only choose two stones... it might be a 400 and 3000. I don't find a need for any more than 3000 in the kitchen.
Coarse stones can be misunderstood. True... their primary use is thinning, removing chips and reseting bevels. Why? Because they remove steel quickly. But that doesnt mean you only have to use them for those tasks. Coarse stones are actually far more versatile than high grit stones. You can get coarse grit stones to mimic high grit stones to some degree but not vice versa. It is about pressure control. In the right hands a coarse stone can produce an edge that is sharper than necessary for use in the kitchen.
Semantics becomes a quagmire... Maybe people associate coarse grit with 'coarse edge'... and to some degree that is true but not in others. If 'sharp' basically means forming a perfectly triangular apex, then it doesn't really matter what grit you choose. All grits are capable of abrading steel into that triangular apex. In that way, a coarse stone can get pretty much just as 'sharp' and fine stone. The difference is that coarse stones leaves deeper scratches - so the edge will be toothier. As you increase the grit, the teeth become smaller. If you want to be pedantic... then yes, you might might get a finer and more uniform apex at higher grits because the abrading grit is smaller. But you wont notice micrometer scale effects when cutting a potato... And you wont achieve those micrometer differences unless you are very good at sharpening.
If it isn't clear... you don't have to use lots of pressure or many strokes on a coarse grit stone. That job that takes you 45 minutes on a 3000 might take you 2-5 minutes on a coarse-mid grit and 2-5 minutes on a 3000. Like I said earlier. There is no right way to sharpen if the end result is 'sharp'... 'better' or 'right' is a value judgement on what is important to you. Just know that you don't need to spend 45 minutes sharpening unless you want to.
@ChefDan96,
There is no 'right' way to sharpen a knife. Many methods can get you the results you desire. That said, collective wisdom is a good shortcut for avoiding mistakes or unproductive behaviour.
I believe low-mid grits are indispensable in the kitchen and it is a good option to have proper low grit stones. In fact I will contend that if *I* had to choose only one stone it would probably be a low-mid grit like 800-1000. If I could only choose two stones... it might be a 400 and 3000. I don't find a need for any more than 3000 in the kitchen.
Coarse stones can be misunderstood. True... their primary use is thinning, removing chips and reseting bevels. Why? Because they remove steel quickly. But that doesnt mean you only have to use them for those tasks. Coarse stones are actually far more versatile than high grit stones. You can get coarse grit stones to mimic high grit stones to some degree but not vice versa. It is about pressure control. In the right hands a coarse stone can produce an edge that is sharper than necessary for use in the kitchen.
Semantics becomes a quagmire... Maybe people associate coarse grit with 'coarse edge'... and to some degree that is true but not in others. If 'sharp' basically means forming a perfectly triangular apex, then it doesn't really matter what grit you choose. All grits are capable of abrading steel into that triangular apex. In that way, a coarse stone can get pretty much just as 'sharp' and fine stone. The difference is that coarse stones leaves deeper scratches - so the edge will be toothier. As you increase the grit, the teeth become smaller. If you want to be pedantic... then yes, you might might get a finer and more uniform apex at higher grits because the abrading grit is smaller. But you wont notice micrometer scale effects when cutting a potato... And you wont achieve those micrometer differences unless you are very good at sharpening.
If it isn't clear... you don't have to use lots of pressure or many strokes on a coarse grit stone. That job that takes you 45 minutes on a 3000 might take you 2-5 minutes on a coarse-mid grit and 2-5 minutes on a 3000. Like I said earlier. There is no right way to sharpen if the end result is 'sharp'... 'better' or 'right' is a value judgement on what is important to you. Just know that you don't need to spend 45 minutes sharpening unless you want to.
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KingShapton
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Absolutely true!!!!
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I use a medium-coarse not only for thinning behind the edge, but also for the primary bevel. Little pressure, just a few strokes. Depending on the steel, edge stability will benefit a lot. As for maintenance touch ups, I use Blue Belgian Brocken. A few strokes to revive the edge. Will work very long with a home user, before the edge needs some refreshing by a 2k. Only when that one doesn't work within again a few strokes it's time for a full sharpening again, starting at 400 or 500, followed by a Chosera 800 and ending by stropping and deburring at 3k.
The proper dai on the right is an example of @childermass 's excellent work. On the left is just me epoxy-ing my favourite slate onto a piece of Australian Cypress yesterday. Still looks nice tho! And a lot better to use as it's not massively thick.
That piece of Australian Cypress looks really nice together with this slate.
