# Sharp Edge vs Durable Edge: An Open-ended Discussion



## StonedEdge (Apr 24, 2017)

I'd like to pick the collective KKF brain on what constitutes a sharp edge and what constitutes a durable edge, as well as sharpening techniques that lend themselves to either/or. 

Clearly, the two are not mutually exclusive. You can have a sharp knife that dulls quickly, a sharp knife that dulls slowly, a kind of sharp knife that dulls slowly, a kind of sharp knife that dulls quickly...You get the idea.

What I'd like to hear from you all is your opinions on how to achieve/the fundamental principles behind a sharp edge that dulls slowly (regardless of steel type or the knife's intended use). 

Generally-speaking is there a sort of hierarchy of 'sharpness factors' behind achieving a sharp, long lasting edge on most any knife?

For example:
-Overall blade geometry; will a thin blade behind the edge always act and feel sharper than a bevel with more shoulders?

-Unearthing new/unfatigued steel to sharpen

-Angle (more obtuse= less 'sharp' the knife? more accute=more 'sharp' the knife?)

-Consistency of angle (more consistent the angle held=sharper knife AND longer lasting "sharpness"?)

-Level of polish/burr refinement (the more refined the burr the sharper the knife is? The more polished the edge, the sharper the knife is?)

-The use of micro-bevels (does using a koba always=longer lasting sharpness?)

What I'm trying to arrive at here is twofold:
What do you individual sharpeners consider "screaming sharp" on a work knife (chef knife, petty, parer... Anything that gets a good amount of action and contact with harder objects) and what do you consider screaming sharp on a knife that sees less/more delicate action such as a sujihiki, yanagiba, ham slicer, western style filet knife, etc...
Is your definition of "screaming sharp" identical for these two different sets of tasks/blades? Are they different? 

And

How long do you expect your newly sharpened Chef's/petty/whatever to hold its wicked edge until you need to touch it up briefly? Do you sharpen some knives with durability in mind, sacrificing net sharpness while others with maximum sharpness in mind while sacrificing durability? Is there a harmonious middle-ground between the two? Do you base your expectations of the knife you're sharpening according to its form, intended function, blade geometry and blade material(s) or do you expect all of the knives in your block to be able to achieve a similar degree of perceived sharpness?

I realize I'm asking many questions (some may even be of the dumb variety). I eagerly await your insights and contributions.


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## GorillaGrunt (Apr 24, 2017)

+1 want some expert input on this.


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## StonedEdge (Apr 24, 2017)

GorillaGrunt said:


> +1 want some expert input on this.



Thanks for the thread bump! Beyond asking folks in person I'm intrigued to see what people on this board have to say.


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## DaveInMesa (Apr 24, 2017)

+2 on wanting some expert input. Hopefully, this thread won't be just people saying they'd like information.


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## LifeByA1000Cuts (Apr 24, 2017)

"the more refined the burr the sharper the knife is"

I think it is more a case of "the more gone for good any burr is the longer the edge will last"


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## panda (Apr 24, 2017)

There's no magic trick. Each steel has different properties, just gotta try multiple angles to find the sweet spot. I purposely use a more obtuse angle for more durability it thin heavily behind the edge to maintain cutting performance.


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## StonedEdge (Apr 24, 2017)

LifeByA1000Cuts said:


> "the more refined the burr the sharper the knife is"
> 
> I think it is more a case of "the more gone for good any burr is the longer the edge will last"



That's a good way to put it. I never thought of it that way.


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## StonedEdge (Apr 24, 2017)

panda said:


> There's no magic trick. Each steel has different properties, just gotta try multiple angles to find the sweet spot. I purposely use a more obtuse angle for more durability it thin heavily behind the edge to maintain cutting performance.



This is what I'm trying to get at (I think)...can you achieve a very sharp, very refined edge, while making this edge last through thorough use (thinking chef's&#8203; knife or petty something along those lines), without having it be a) brittle/chippy/rolling over on itself and b) so obtuse so as to hinder performance?

Furthermore what is everyone's description of a burr having been satisfactorily removed?


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## StonedEdge (Apr 24, 2017)

DaveInMesa said:


> +2 on wanting some expert input. Hopefully, this thread won't be just people saying they'd like information.



Even if it is, as an open-ended discussion almost anything is classified as a contribution and may help in getting some more insight down the road when we're all gone and virtual archeologists unearth this thread from the sands of time.


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## Benuser (Apr 24, 2017)

The most durable edge is very thin behind an obtuse edge.


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## StonedEdge (Apr 24, 2017)

Maybe I'm not thinking this through or maybe I failed Gade 6 geometry...But is it possible to have a primary bevel that is at a more accute angle than the cutting edge?


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## Benuser (Apr 24, 2017)

The cutting edge is always more obtuse than the relief bevel.


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## LifeByA1000Cuts (Apr 24, 2017)

@Benuser heard of the Ryusen V-Metal series that was recently on sale in Germany? VG10 blade very similar to a Tak R2 in construction... but with a 22/15 (counter-asymmetric as you love it) secondary bevel instead of a 9/9 OOTB. And yes, that thing is durable as all hell for a laser.

And in a way, Kiwis are of a similar ilk (14dps in front of a hollow grind section).


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## LifeByA1000Cuts (Apr 24, 2017)

@StonedEdge this would be a burr usually  Though I guess some hollow grinding of a very thin edge can happen if you use too much pressure...


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## scott.livesey (Apr 24, 2017)

without getting into numbers, as they are very hard to measure at angles less than 20 degrees, I sharpen to where I can push cut newsprint and shave arm hair without pulling. I have several thin(1/16" at the spine) blades where the edge has been ground to 0.005", is 0.02" 1/4" above the edge and 0.03" 1/2" above the edge. the maker said the steel is at Rc62-64. No chipping so far, but I only use these blades for boneless proteins, fruit, and vegetables using a HDPE or edge grain cutting board.


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## foody518 (Apr 24, 2017)

StonedEdge said:


> Maybe I'm not thinking this through or maybe I failed Gade 6 geometry...But is it possible to have a primary bevel that is at a more accute angle than the cutting edge?



If you had a way of putting in a concave grind, sure. Will you be able to get that result sharpening on flat stones? No. You wouldn't be able to reach the edge to put on a more acute angle than the rest of the blade grind dictates.

"-Overall blade geometry; will a thin blade behind the edge always act and feel sharper than a bevel with more shoulders?

-Unearthing new/unfatigued steel to sharpen

-Angle (more obtuse= less 'sharp' the knife? more accute=more 'sharp' the knife?)

-Consistency of angle (more consistent the angle held=sharper knife AND longer lasting "sharpness"?)

-Level of polish/burr refinement (the more refined the burr the sharper the knife is? The more polished the edge, the sharper the knife is?)

-The use of micro-bevels (does using a koba always=longer lasting sharpness?)"

At least 2 of these are talking about perceived sharpness/ease of cutting due to geometry and thin/thickness right behind the edge and up. Yes, makes a difference

Consistency of angle in the course of a sharpening session - cleaner apex

You'll want to deburr as much as you can manage to. High grit sharpness and lower grit sharpness feel different. You can 3 finger test this

Microbevels - tempering the tradeoff of a too fragile at or right behind the edge geometry (great cutting ease) with having a edge apex that doesn't blunt or chip or crumble too quickly. If you have too big a microbevel on a knife that isn't already thin/wouldn't be a cadidate for microbevel, it'll show in decreased cutting performance even if durability could improve. Just tradeoffs and preferences


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## StonedEdge (Apr 25, 2017)

foody518 said:


> You'll want to deburr as much as you can manage to. High grit sharpness and lower grit sharpness feel different. You can 3 finger test this



What's a good sign (optically, through feel, intuition.. whatever it may be) that you've satisfactorily removed the burr from the edge? Before moving on to stropping, cork, felt, etc


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## Benuser (Apr 25, 2017)

When the thin burr can't be reduced any further and only flips, it's time to go to the next stone. Not before.


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## StonedEdge (Apr 25, 2017)

Benuser said:


> When the thin burr can't be reduced any further and only flips, it's time to go to the next stone. Not before.



I'm assuming this is judged entirely by feel?


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## Ruso (Apr 25, 2017)

Benuser said:


> When the thin burr can't be reduced any further and only flips, it's time to go to the next stone. Not before.


Sounds like a waste of time. Higher grit stone will reduce the burr in either or situation.


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## Benuser (Apr 25, 2017)

StonedEdge said:


> I'm assuming this is judged entirely by feel?



Indeed


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## LifeByA1000Cuts (Apr 25, 2017)

I could think of two reasons for Benuser's recommendation:

-Big burr pieces are gonna put big scratches into your finishers and blade if they come off at the wrong time.

-A large, stable burr on a thin, flexible edge probably will turn into part of that edge instead when treated too gently... I've had that kind of fun with the usubas, made a big burr and had big trouble getting rid of it because the edge was acting as a shock mount for it...


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## foody518 (Apr 25, 2017)

StonedEdge said:


> What's a good sign (optically, through feel, intuition.. whatever it may be) that you've satisfactorily removed the burr from the edge? Before moving on to stropping, cork, felt, etc



The thing where you curl your fingers or thumb up and over the edge along various spots (to feel for burr) 
also 3 finger test different sections along the edge (post deburring to check how you did)
Cleanliness of stuff like paper towel cutting (post deburring, to see if you did a good job and got the aggressiveness you did it didn't want) - it'll still tug or tear when it hits a not as cleanly done spot.


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## StonedEdge (Apr 25, 2017)

Benuser, LifeByA1000Cuts both of what you're stating make complete sense to me. I'm starting to think part of my issue in achieving a durable but still very sharp edge is the fact that my fingers are not educated (for lack of a better term) in the matter of detecting burrs once they become exceedingly small. I maybe be going to the finishing stones/stropp a little early. Great input on this subject to all who've contributed so far thank you all!


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## Ruso (Apr 25, 2017)

LifeByA1000Cuts said:


> I could think of two reasons for Benuser's recommendation:
> 
> -Big burr pieces are gonna put big scratches into your finishers and blade if they come off at the wrong time.
> 
> -A large, stable burr on a thin, flexible edge probably will turn into part of that edge instead when treated too gently... I've had that kind of fun with the usubas, made a big burr and had big trouble getting rid of it because the edge was acting as a shock mount for it...



How big of a burr are you creatig to affect the final finish due to scratches on the stone? Unless it's reprofiling/repair - one should always try to create the smallest burr possible.

I can see the problem with single bevel knife due to specifics of of left side being "sharpened" flat; but on double bevel as long as you always hit the apex/edge I do not see any problem.
Wobbling is the enemy number 1 IMHO.


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## Benuser (Apr 25, 2017)

@StonedEdge: feel the burr vertically with your nail. Or feel with your thumb's flesh, against the edge, which side feels the sharpest. That's where there's some burr. And eventually feel along the edge with your nail whether a bevel feels smooth.


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## malexthekid (Apr 25, 2017)

Watch some of Jon's (JKI) sharpening videos. He goes through burr formation. How he feels for it, removal etc.


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## natto (Apr 26, 2017)

Burrs are visible with a good loupe. Sunlight directed to the edge can show a small shadow line from the burr. It's tricky to adjust, but if the shadow is on the opposite site only, it's a burr. With good light I can detect burrs which are hard to feel. The loupe helped me to learn how to feel for the burr.


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## LifeByA1000Cuts (Apr 26, 2017)

Some coarse stones make rather visible burrs... but these should indeed only occur in the kind of work where you are using coarse stones in the first place I guess


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## natto (Apr 26, 2017)

LifeByA1000Cuts said:


> Some coarse stones make rather visible burrs... but these should indeed only occur in the kind of work where you are using coarse stones in the first place I guess


Forgotten to turn the knife?


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## scott.livesey (Apr 26, 2017)

I mark the edge with a sharpie. when sharpie marks are gone, time for next stone


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## Benuser (Apr 26, 2017)

No burr chasing?


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## StonedEdge (Apr 26, 2017)

natto said:


> Burrs are visible with a good loupe. Sunlight directed to the edge can show a small shadow line from the burr. It's tricky to adjust, but if the shadow is on the opposite site only, it's a burr. With good light I can detect burrs which are hard to feel. The loupe helped me to learn how to feel for the burr.



I've been considering using some sort of magnification but thought it might be a little overkill. I'll definitely try it next sharpening session so I can see what my fingers feel. Good tip!


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## zetieum (Apr 26, 2017)

StonedEdge said:


> I've been considering using some sort of magnification but thought it might be a little overkill. I'll definitely try it next sharpening session so I can see what my fingers feel. Good tip!



IMHO, magnification is very useful to get "educated". In the beginning it helps to make the connection between what you fell on the fingers to what you see, afterwards, it becomes less useful. 
Another very useful way to feel the bur is to compare the both side of the blade. 
Finally, sharpie is ALWAYS useful, advanced or beginner.
EDIT: I am no expert nor professional. I just share here what helped me in the beginning, in hope it can help others


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## Benuser (Apr 26, 2017)

zetieum said:


> IMHO, magnification is very useful to get "educated". In the beginning it helps to make the connection between what you fell on the fingers to what you see, afterwards, it becomes less useful.
> Another very useful way to feel the bur is to compare the both side of the blade.
> Finally, sharpie is ALWAYS useful, advanced or beginner.
> EDIT: I am no expert nor professional. I just share here what helped me in the beginning, in hope it can help others


Thanks for explaining, Zetium.


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## LifeByA1000Cuts (Apr 26, 2017)

@natto or crass angle changes, eg completely getting rid of a secondary bevel....


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## Benuser (Apr 26, 2017)

Time for thinning by refreshing the relief bevel, and, by doing so, reduce the width of the primary bevel.


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## scott.livesey (Apr 26, 2017)

Benuser said:


> No burr chasing?



If I have a burr, it is so slight that the next stone quickly takes care of it.
all seriousness aside, if someone claims they are excellent sharpener, ask to see their forearms. most serious sharpeners I have met have numerous bald patches on their forearms. for me sharp means able to shave arm hair without pulling and push cut newsprint.


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## GorillaGrunt (Apr 26, 2017)

scott.livesey said:


> If I have a burr, it is so slight that the next stone quickly takes care of it.
> all seriousness aside, if someone claims they are excellent sharpener, ask to see their forearms. most serious sharpeners I have met have numerous bald patches on their forearms. for me sharp means able to shave arm hair without pulling and push cut newsprint.



Lol, yep, mostly hairless left arm  Supposedly back around 1900 they used to call this "knife fighter's mange" but I don't remember where I read this; it may not be historical.


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## Ruso (Apr 26, 2017)

scott.livesey said:


> for me sharp means able to shave arm hair without pulling and push cut newsprint.


I used to be impressed about things like this or slicing a tomato hands free. Now, this is a mere stating point.


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## foody518 (Apr 26, 2017)

I could see how you get minimal burr with moving on as soon as the sharpie is gone...that takes 1-2 strokes...


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## jklip13 (Apr 26, 2017)

What is blowing my mind in previous comments is that people are forming burrs, are correctly identifying them, acknowledging them, then continuing to sharpen and progressing onto further stones, without removing them. Why! Your edges will be so much sharper, stay so much sharper and be so much easier to use! Is it possible there is an other definition of burr that I'm missing? We're talking about the scraggly thread of metal that forms along the edge as the two planes are abraded away and meet at the apex of the edge right? The wispy scrap of steel that may feel sharp but crumples over the edge after even a little contact on hard cutting boards - right?


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## foody518 (Apr 27, 2017)

jklip13 said:


> What is blowing my mind in previous comments is that people are forming burrs, are correctly identifying them, acknowledging them, then continuing to sharpen and progressing onto further stones, without removing them. Why! Your edges will be so much sharper, stay so much sharper and be so much easier to use! Is it possible there is an other definition of burr that I'm missing? We're talking about the scraggly thread of metal that forms along the edge as the two planes are abraded away and meet at the apex of the edge right? The wispy scrap of steel that may feel sharp but crumples over the edge after even a little contact on hard cutting boards - right?



I think the assumption is being made that the next stone in the progression will start to work down the burr from the previous stone and get you a net smaller burr...then the next stone will do that again. Or that you can completely remove the previously generated burr on the next stone, and having larger burr does not compromise your ability to refine the edge apex with the finer stone. Or that by the time you get to your final stone, you can do all the necessary deburring completely there and not before. My sharpening's gone better since assuming that is not the case.


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## scott.livesey (Apr 27, 2017)

Ruso said:


> I used to be impressed about things like this or slicing a tomato hands free. Now, this is a mere stating point.



agreed, but that is as far as i go for an edge that will last. a much finer edge can be made, but seldom lasts more than a celery stalk or two.


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## LifeByA1000Cuts (Apr 27, 2017)

There's also the assumption that gung-ho burr removal methods, especially without extended stropping on a stone (where the finer stone comes in anyway - why remove more metal than necessary?), aren't for every steel  A big, non-stropped burr will maybe succumb to hardwood, but as someone else pointed out last time i mentioned hardwood deburring here - not for every steel and bevel angle  I guess it's like tearing off a length of your fingernail - either it works surprisingly clean or ends up very rough


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## Benuser (Apr 27, 2017)

foody518 said:


> I think the assumption is being made that the next stone in the progression will start to work down the burr from the previous stone and get you a net smaller burr...then the next stone will do that again. Or that you can completely remove the previously generated burr on the next stone, and having larger burr does not compromise your ability to refine the edge apex with the finer stone. Or that by the time you get to your final stone, you can do all the necessary deburring completely there and not before. My sharpening's gone better since assuming that is not the case.


+1
So very well formulated.


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## LifeByA1000Cuts (Apr 27, 2017)

Certainly, when setting an edge you want to check the quality of your edge before going near a polishing stone, so that requires some deburring anyway...


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## Benuser (Apr 27, 2017)

You better solve problems where they occur. If you raise a fat burr with a coarse stone, have it reduced as far as possible with that very stone, before going to the next one.


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## LifeByA1000Cuts (Apr 28, 2017)

@Benuser "fat burr" like my pathological "thinned VG10 to zero on a light green chosera, the burr is sparkling ominously", or your normal kind of burr?


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## Benuser (Apr 28, 2017)

The kind of burr you raise on a coarse stone when working on a neglected blade.


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## Ruso (Apr 28, 2017)

foody518 said:


> I think the assumption is being made that the next stone in the progression will start to work down the burr from the previous stone and get you a net smaller burr...then the next stone will do that again. Or that you can completely remove the previously generated burr on the next stone, and having larger burr does not compromise your ability to refine the edge apex with the finer stone. Or that by the time you get to your final stone, you can do all the necessary deburring completely there and not before. My sharpening's gone better since assuming that is not the case.



The caveat is, that this is not an assumption.


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## StonedEdge (Apr 28, 2017)

Of my limited knowledge of knife sharpening, I always took the concept of reducing the burr down to its smallest possible form before moving on to another stone to be a rule written in...wait for it..... stone.


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## Benuser (Apr 29, 2017)

Exactly


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## Ruso (Apr 29, 2017)

To each their own I guess. Use what works for you.
If you experience problems with burrs removal by moving to higher grit though, try creating the small/minimal burr to start with and to keep consistent angle across all stones. The key to hit the same apex with every stroke


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## _PixelNinja (Apr 30, 2017)

jklip13 said:


> What is blowing my mind in previous comments is that people are forming burrs, are correctly identifying them, acknowledging them, then continuing to sharpen and progressing onto further stones, without removing them. Why! Your edges will be so much sharper, stay so much sharper and be so much easier to use! Is it possible there is an other definition of burr that I'm missing? We're talking about the scraggly thread of metal that forms along the edge as the two planes are abraded away and meet at the apex of the edge right? The wispy scrap of steel that may feel sharp but crumples over the edge after even a little contact on hard cutting boards - right?


I have talked to Jon (Broida) about this in the past. He has also addressed this in his sharpening videos and here and there on forums/comment sections/whatnot. Either way works (and for what it's worth he said he does not remove burrs between stones).



foody518 said:


> I think the assumption is being made that the next stone in the progression will start to work down the burr from the previous stone and get you a net smaller burr...then the next stone will do that again. Or that you can completely remove the previously generated burr on the next stone, and having larger burr does not compromise your ability to refine the edge apex with the finer stone. Or that by the time you get to your final stone, you can do all the necessary deburring completely there and not before. My sharpening's gone better since assuming that is not the case.





Ruso said:


> The caveat is, that this is not an assumption.


This.


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## jklip13 (Apr 30, 2017)

_PixelNinja said:


> I have talked to Jon (Broida) about this in the past. He has also addressed this in his sharpening videos and here and there on forums/comment sections/whatnot. Either way works (and for what it's worth he said he does not remove burrs between stones).
> 
> 
> 
> This.



I would be really surprised if any professional sharpener was creating and acknowledging burrs and moving onto further steps without doing anything to minimize or remove them. Maybe he meant he removes or does not develop large burs on the stones so he does not use "deburring" techniques between stones? No idea, just a guess


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## nutmeg (May 1, 2017)

I've always thought that sharpening was the action to clean the corner (edge). 
Assuming most of people here use an equal or higher grit than #2000 or even #1000, maybe I missed something but after that, when the job is done, when the angle is clean, there should not be any burr left. Maybe too much pressure on the stones at the end?


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## LifeByA1000Cuts (May 1, 2017)

My definition would be "it means destroying the existing edge, using the burr as a proof of its destruction, and putting a new edge on at the same time"....


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## nutmeg (May 1, 2017)

I would understand it like this too.
Anyway if we are in a phase of destruction of an existing edge, it is a violent fixing/repairing process and even if burr appears it not very important because it is will be gone at the end of the sharpening, when the blade is finish.
For example, why people think of the past #400 and #800 burr as a problem when they've been afterwards finishing the edge on a #2000?


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## foody518 (May 1, 2017)

What about the concept or anectodal experience of 'tenacious burrs'?


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## LifeByA1000Cuts (May 1, 2017)

If intended, would that not be otherwise known as a hollow grind (which seems to be much maligned in culinary knives)?


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## foody518 (May 1, 2017)

LifeByA1000Cuts said:


> If intended, would that not be otherwise known as a hollow grind (which seems to be much maligned in culinary knives)?



In reference to which previous comment?


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## malexthekid (May 2, 2017)

jklip13 said:


> I would be really surprised if any professional sharpener was creating and acknowledging burrs and moving onto further steps without doing anything to minimize or remove them. Maybe he meant he removes or does not develop large burs on the stones so he does not use "deburring" techniques between stones? No idea, just a guess



Can I ask why you feel one type of abrading a burr is different than another?

I think the answer lies in the fact that there are as many ways to deburr as their are sharpeners.


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## natto (May 2, 2017)

I would like to know how much of a burr can be removed? My edges last longer since I guess only to reduce them. I know many ways to reduce the burr, but I don't know how to get the proof it is gone.


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## LifeByA1000Cuts (May 2, 2017)

@foody518 tenacious burrs etc...


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## foody518 (May 2, 2017)

@Life - I feel like we've got pretty different mental images in mind if you thought of hollow grind as associated with tenacious burrs. I was just thinking about the reputation that some (or many) knives of VG10 steels and maybe some other steels get as being hard to deburr - more steps could be needed or a different approach. 
Just musing - I remember seeing I think SEM photos on a blog (science of sharp blog?) that actually shows cross sectional photos of the edge apex of a razor. It's the part I'm not used to seeing since it's easier to inspect the bevels. One photo that stuck out to me was of edge trailing strokes that drew out a burr, and even running it through a grabby material simply folded the burr over the apex instead of pulling it off, not something I'd really be able to tell without those tools. Gave me an impression that even if the burr is flipping with each edge trailing stroke, there could still be some gunk actually stuck on the apex, not pulled or drawn off with ease. Whereas edge leading strokes I think tended to slightly truncate the apex. It's about preferences I guess...
So I've experimented with trying to be more careful and make fewer assumptions about my routine and what 'should be enough'.


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## LifeByA1000Cuts (May 2, 2017)

Ah, so you mean unwanted burrs


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## StonedEdge (May 2, 2017)

natto said:


> but I don't know how to get the proof it is gone.



THIS. Is there generally any ways to verify if/when a burr is truly gone? Other than specialized scientifc equipment.


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## foody518 (May 2, 2017)

LifeByA1000Cuts said:


> Ah, so you mean unwanted burrs



Yes, as the latter part of this thread has been around the topic of whether certain approaches do effectively do remove all (or enough) burr, got me thinking


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## Benuser (May 3, 2017)

StonedEdge said:


> THIS. Is there generally any ways to verify if/when a burr is truly gone? Other than specialized scientifc equipment.



Your will hear it when cutting fine cigarette paper. Smooth and almost silent cuts vs. ragged and loud ones.


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## StonedEdge (May 3, 2017)

Benuser said:


> Your will hear it when cutting fine cigarette paper. Smooth and almost silent cuts vs. ragged and loud ones.



Oh wow, never thought of using rolling papers for this purpose. Makes complete sense! I will definitely use this trick. Many thanks!


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## Benuser (May 3, 2017)

You're welcome! Get the thinnest you may get.


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## scott.livesey (May 3, 2017)

foody518 said:


> @Life - I feel like we've got pretty different mental images in mind if you thought of hollow grind as associated with tenacious burrs. I was just thinking about the reputation that some (or many) knives of VG10 steels and maybe some other steels get as being hard to deburr - more steps could be needed or a different approach.
> Just musing - I remember seeing I think SEM photos on a blog (science of sharp blog?) that actually shows cross sectional photos of the edge apex of a razor. It's the part I'm not used to seeing since it's easier to inspect the bevels. One photo that stuck out to me was of edge trailing strokes that drew out a burr, and even running it through a grabby material simply folded the burr over the apex instead of pulling it off, not something I'd really be able to tell without those tools. Gave me an impression that even if the burr is flipping with each edge trailing stroke, there could still be some gunk actually stuck on the apex, not pulled or drawn off with ease. Whereas edge leading strokes I think tended to slightly truncate the apex. It's about preferences I guess...
> So I've experimented with trying to be more careful and make fewer assumptions about my routine and what 'should be enough'.



here is a source that has SEM pictures of edges after various sharpening methods https://archive.org/details/Experiments_on_Knife_Sharpening_John_Verhoeven the experiments include Tru-Hone machine, Tormek machine, water stones, oil stones, leather strops with various compounds, and buffing wheels.


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## Ruso (May 4, 2017)

scott.livesey said:


> here is a source that has SEM pictures of edges after various sharpening methods https://archive.org/details/Experiments_on_Knife_Sharpening_John_Verhoeven the experiments include Tru-Hone machine, Tormek machine, water stones, oil stones, leather strops with various compounds, and buffing wheels.



One of the conclusions (p23) grabbed my attention.

"1 Japanese waterstones in the 6000 to 8000 grit range produced an excellent edge on these HRC = 60 stainless steel blades with as-ground 2&#946; edge angles of around 40o. The waterstones produced fairly smooth and quite straight edges as viewed face-on. The remnant bur width was quite small, on the order of 0.5 microns. The edge quality was independent of the size of the burs left from the original grinding with either 600 grit or 1000 grit wheels. The coarser original burs of the as-ground 600 grit blades and the finer burs of the as-ground 1000 grit blades were both replaced with similar edge geometries. "


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## ecrphoto (May 6, 2017)

Not exactly SEM, but I have been taking a 50MP medium format digital camera back to my recent purchases to see what I'll want to do with the edges, as well as the overall finish. Fascinating to see up close (highly recommended clicking through if you want to get details, zoom in tight). 

KUROUCHI KIRITSUKE-SHAPED SANTOKU from JKI. Quickly became one of my favorite knives after purchasing. These shots were mid-sharpen, obviously looked a hell of a lot better when it came straight from Jon. 


KnifeFUn 1 by evan, on Flickr


KnifeFUn 10 by evan, on Flickr


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## StonedEdge (May 25, 2017)

Lets say you're sharpening your go-to chef's or petty or whatever double bevel needs some freshening up..how does everyone feel about:

Option #1: raising a burr on progressively finer stones without much attention to reducing/removing the burrs until the end... deburring fully and completely following the last stone of your progression

Option #2: Raising a burr on the first stone and using your progressively finer stones strictly as a means to refine the edge you've established on your first stone (using them to incrementally abrade away the burr raised on the first stone, never raising more burrs through your progression) this can include using the stones as stropes before moving on to the next stone, with whatever final stropping/final deburring technique you order at the very end.

Option #3: Setting the new bevel with your first stone, completely deburring using this stone plus stropping, cork, felt and/or whatever else tickles your fancy, then moving on to progressively finer stones while raising a new albeit smaller burr with each stone and repeating the complete burr removal process mentioned above (stropping, pulling through felt, etc) after each stone until you judge that you're finished. 

Would love to hear everyone's preferences or opinions on which of the aforementioned plans of attack is superior or if there are different protocols that you use that yeild excellent results?


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## foody518 (May 25, 2017)

Does option 2 include strop strokes and some slightly edge leading full sweeps and or lateral strokes?


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## StonedEdge (May 25, 2017)

foody518 said:


> Does option 2 include strop strokes and some slightly edge leading full sweeps and or lateral strokes?



Yes for sure. I've gone back and made some edits in options 2 and 3 to be more clear.


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## Benuser (May 25, 2017)

Not sure I understand very well. After raising a burr with the first stone, and reducing it, some burr will remain. I go to the next stone when it can't be further reduced, and only flips. With the next stone, no need for raising a burr, it's still there, as becomes obvious after two strokes or so.


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## Krassi (May 26, 2017)

my 50cents.. I first flatten the blade to 0 degrees on both sides and then put it in my sharpening system and give it a 16 degrees per side microphase starting with a suita. Ok of course i mean i keep one side slightly convex. since asymetric has the best food release behavior for me
i never care about burrs.. i pull my knifes through a piece of cork after every stone and just use my thumb to feel if its ok.It will work .. same with cooking for me.. i know what i put in and it will work.

This is a no brainer and the knifes are super sick sharp with a very robust edge. and it will be 100% every time.. even when iam drunken.
I like this way .. and freehand is for fun and kasumi and to make it 0 degrees.

So maybe this sounds stupid.. but if its stupid and it works its not stupid


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## LifeByA1000Cuts (May 27, 2017)

OK, am I imagining this or is the 1.4116 on a Zwilling gourmet actually coarser (from the way it reacts to polishing stones) than some cheap-but-done-correctly 420J2 (Kiwi/Sekiryu etc....)?


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