# Sharpening wide bevel knives



## Nemo (Jan 16, 2017)

Hi all of you sharpening gurus,

Just wanted a rundown on how to sharpen wide bevel double bevels (yeah, I know, rub it on a rock, right? &#128526; ).

Do you use the wide bevel as a kind of relief or thinning bevel and add a more obtuse primary bevel? Or do you use the wide bevel as the (fairly steep) primary (and maybe add a microbevel)? Or do you try to convex them, a bit like you are doing a double bevel hamiguriba?

Thanks for your input.


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## foody518 (Jan 16, 2017)

Glad you started this thread, honestly. I've been musing about the different ways to go about this recently as well.

Currently doing - hitting the wide bevel (one of the knives flat, another a really wonky convex) and then doing a ~10-20 dps at the very edge. Mainly because the knives came to me with a small edge bevel so I just kept up with that and didn't think about it too much until like a month or two ago. Another couple I haven't gotten around to touching the wide bevel yet. I'd like to try and understand if some of those knives are candidates for hamaguri-ba plus micro.

Curious about what others are doing for theirs!


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## XooMG (Jan 16, 2017)

Higher bevel coarse grinding, then lower bevel coarse grinding to set desired convexity, then finish high and low, then microbevel.


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## foody518 (Jan 16, 2017)

XooMG said:


> Higher bevel coarse grinding, then lower bevel coarse grinding to set desired convexity, then finish high and low, then microbevel.



One sided microbevel? And then deburr on back side (at what angle) ?


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## Nemo (Jan 16, 2017)

XooMG said:


> Higher bevel coarse grinding, then lower bevel coarse grinding to set desired convexity, then finish high and low, then microbevel.



Is this like doing a hamguriba on each side or do I have the wrong idea? This is essentially how I've sharpened my wide bevel Mizuno Hontanren and it works really well.

Is this true of all wide bevels, including those that come flat ground OOTB?

I'm pretty sure my Kagekiyo is a flat ground wide bevel (correct me if it's not).


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## foody518 (Jan 16, 2017)

You can ease a flat ground wide bevel into a hamaguri-ba slowly over time by adjusting where pressure is. I think there's also something of a 'some knives are made to work best a certain way' that I'm trying to dig into. I was told to keep my Moritaka as flat ground on the wide bevel.


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## XooMG (Jan 16, 2017)

foody518 said:


> One sided microbevel? And then deburr on back side (at what angle) ?


I do not adhere to any specific prescription there. I sharpen intuitively with five conditions: material limits, overall geometry, intended use, available/convenient methods, and personal whim. Usually very subtle double bevel with microconvexing and slight final edge chasing.

Yesterday I sharpened my thin cleaver by making a convex to about zero, deburred and microconvexed on a hanging fabric strop with autosol paste, then chased the edge slightly with tenjo nagura on a hard stone, then slight stropping on unloaded cardboard at a low angle.

Before that I sharpened a Zakuri with a basic microbevel that was moderately high angle on the left side, bout half as high on the right, deburring on some old cotton underwear that was loaded with a bunch of fine stone grit (wiped extra mud off blade when polishing), and rechasing the edge with a few strokes on a hard-ish wakasa stone with a little raised slurry.


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## XooMG (Jan 16, 2017)

Nemo said:


> Is this like doing a hamguriba on each side or do I have the wrong idea? This is essentially how I've sharpened my wide bevel Mizuno Hontanren and it works really well.
> 
> Is this true of all wide bevels, including those that come flat ground OOTB?
> 
> I'm pretty sure my Kagekiyo is a flat ground wide bevel (correct me if it's not).


Depends. If the knife cuts really well, then keep it. If you think it can be improved, improve it.

Some knives mature with a few sharpenings and thinnings, and some seem happy where they are and want to be preserved. I added convexity to a Takeda nakiri, but in the end decided it was happier with a short, mostly flat bevel.

Generally, I like appropriate convexity, unless an alternate geometry is really working.

Edit: Please do not take my posts too seriously...I am no authority on sharpening and am in no way qualified to tell folks how to best sharpen.


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## Nemo (Jan 16, 2017)

Is a reasonable approach to this to make small changes incrementally and see how the knife performs?

Maybe just start with blending the shoulders of the primary into the wide bevel?


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## XooMG (Jan 17, 2017)

Nemo said:


> Is a reasonable approach to this to make small changes incrementally and see how the knife performs?


Seems the only reasonable approach, I think.

I am not a fan of just rounding shoulders though. Convexity is most meaningful when better centered. I recommend letting it very very slowly grow with slightly more pressure toward the edge.


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## Nemo (Jan 17, 2017)

Thanks for the feedback Xoo.


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## Badgertooth (Jan 17, 2017)

I'm a lay it flat and go for gold kinda guy. Helps kick up a bit of mud and get things going. Lift a little at the end of each stone to hit the apex - generally when the sound goes from a slippery whoosh to a bit more of a scrape. Helps a lot with stones like Aizu and Tsushima.


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## foody518 (Jan 17, 2017)

I'm thinking any shoulders from a V bevel right at the cutting edge should be pretty miniscule, since isn't one of the strengths of wide bevel knives to be able to achieve and sustain thin behind the edge geometries?


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## panda (Jan 17, 2017)

thin along the bevels until you hit the edge. and then add a primary cutting bevel like you would on a regular geometry knife or just leave the zero edge (not recommended unless you like to sharpen out chips often). eventually it will get fat behind the edge and you will need to raise the shinogi line higher. basically, you will have a rollercoaster performance throughout the life of the blade a lot more pronounced than on a regular bevel knife. you can experiment with easing shoulders, just one or both (including how much you blend).


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## Nemo (Jan 17, 2017)

panda said:


> thin along the bevels until you hit the edge. and then add a primary cutting bevel like you would on a regular geometry knife or just leave the zero edge (not recommended unless you like to sharpen out chips often). eventually it will get fat behind the edge and you will need to raise the shinogi line higher. basically, you will have a rollercoaster performance throughout the life of the blade a lot more pronounced than on a regular bevel knife. you can experiment with easing shoulders, just one or both (including how much you blend).



Should you thin the wide bevel a little every time you sharpen to minimise this roller caoster effect?


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## panda (Jan 17, 2017)

Yes, absolutely


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## Nemo (Jan 17, 2017)

Do you polish the wide bevel to the same extent as the edge or would you stop at, say, 1k? Im guessing more polish gives worse food release but better rust resistance?


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## malexthekid (Jan 17, 2017)

I think the food release of a wide bevel comes mainly from the "sharp" transition at the shoulder the geometry creates.

And the finishing depends more on the aesthetic look you want.. aka the jnat rabbit hole


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## Nemo (Jan 17, 2017)

No! Keep me away from the jnat rabbit hole! :scared:


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## foody518 (Jan 17, 2017)

Nemo said:


> Do you polish the wide bevel to the same extent as the edge or would you stop at, say, 1k? Im guessing more polish gives worse food release but better rust resistance?



Whichever stone I'm feeling :O
Fall down the rabbit hole!


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## Nemo (Jan 17, 2017)

foody518 said:


> Fall down the rabbit hole!



Have you seen the prices of those things? :scared:

More seriously ,though, despite having read hundreds of posts on Jnats, I still have no idea where to start. It's a complete maze to me.


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## foody518 (Jan 17, 2017)

Nemo said:


> Have you seen the prices of those things? :scared:
> 
> More seriously ,though, despite having read hundreds of posts on Jnats, I still have no idea where to start. It's a complete maze to me.



Yes...I already went down the rabbit hole, see


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## Nemo (Jan 17, 2017)

foody518 said:


> Yes...I already went down the rabbit hole, see



Yeah, I figured


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## K813zra (Jan 17, 2017)

Nemo said:


> Have you seen the prices of those things? :scared:
> 
> More seriously ,though, despite having read hundreds of posts on Jnats, I still have no idea where to start. It's a complete maze to me.



The best place to start is wherever you want really. I read and read on the subject to no end and all that did was intimidate me. Against the advice of many others I started with mid range Jnats rather than getting a finisher or rather I went with my gut and I have yet to be disappointed. I continue to order more whenever I get the chance and something that speaks to me pops up. It may sound silly but when I am looking for something it really does scream in my mind, telling me to pick it up. 

I am new at this and by no means qualified to recommend stones to other people, tell them where to start or how to pick what range of stones is right for them. What I can say is that to me sharpening is a hobby, an enjoyable one and using natural stones has made it even more enjoyable. For me it is about the use of the stone as well as collecting and trying to find which stones work better for which knives and best match my technique. 

That said, it really is a rabbit hole. I am rounding a dozen stones and will be adding about half a dozen more by spring.


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## Badgertooth (Jan 17, 2017)

K813zra said:


> The best place to start is wherever you want really. It may sound silly but when I am looking for something it really does scream in my mind, telling me to pick it up.
> 
> What I can say is that to me sharpening is a hobby, an enjoyable one and using natural stones has made it even more enjoyable. For me it is about the use of the stone as well as collecting and trying to find which stones work better for which knives and best match my technique.



A lotta truth in here. Grab something you like the sound of, learn the hell out of it. And go from there.


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## v647c (Jan 17, 2017)

Is this the aogami 2 mizuno gyuto? If so, from memory the convexity of the bevel is pretty mild. A good idea may be to practice sharpening the bevel on a finer stone so that you can get an idea of the curvature without removing too much steel. You can sharpen hamaguriba for sure, but for gyuto with quite a tall bevel I personally don't think it's necessary. A little more pressure when you are at the edge should suffice. Also since the bevel is quite large, I think a 1k finish will probably not be high enough. You will feel the scratches on many ingredients especially if cutting on an angle. At the end of the day, don't overthink it! You won't make the bevel completely flat so easily. And polishing to kasumi finish on a gyuto is really more for looks IMO, or maybe more of an OCD thing haha.


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## Nemo (Jan 17, 2017)

v647c said:


> Is this the aogami 2 mizuno gyuto? If so, from memory the convexity of the bevel is pretty mild. A good idea may be to practice sharpening the bevel on a finer stone so that you can get an idea of the curvature without removing too much steel. You can sharpen hamaguriba for sure, but for gyuto with quite a tall bevel I personally don't think it's necessary. A little more pressure when you are at the edge should suffice. Also since the bevel is quite large, I think a 1k finish will probably not be high enough. You will feel the scratches on many ingredients especially if cutting on an angle. At the end of the day, don't overthink it! You won't make the bevel completely flat so easily. And polishing to kasumi finish on a gyuto is really more for looks IMO, or maybe more of an OCD thing haha.



Yep. I get the impression that the convexity varies a bit. Mine seems to be fairly heavily convexed. Certaimly has very good food release. I sharpened the bevel to 3k last time and it was quite shiny but performed well. Sharpened again last night. The bevel only got 1k. Still looks much shinier than the kasumi finish. So far, performs well but haven't tried any oblique cuts yet and have only used it on zucchini.


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## Nemo (Jan 17, 2017)

K813zra said:


> The best place to start is wherever you want really. I read and read on the subject to no end and all that did was intimidate me. Against the advice of many others I started with mid range Jnats rather than getting a finisher or rather I went with my gut and I have yet to be disappointed. I continue to order more whenever I get the chance and something that speaks to me pops up. It may sound silly but when I am looking for something it really does scream in my mind, telling me to pick it up.
> 
> I am new at this and by no means qualified to recommend stones to other people, tell them where to start or how to pick what range of stones is right for them. What I can say is that to me sharpening is a hobby, an enjoyable one and using natural stones has made it even more enjoyable. For me it is about the use of the stone as well as collecting and trying to find which stones work better for which knives and best match my technique.
> 
> That said, it really is a rabbit hole. I am rounding a dozen stones and will be adding about half a dozen more by spring.



Yeah, I think it might just be a case of buying a reasonable stone and seeing how it performs.


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## Ruso (Jan 17, 2017)

Convex on wide bevel; Does it even make sense? 
If somebody knows a trick how to mantain or create concave wide bevel, that would be much appreciated.

I always refinish wide bevel using sandpaper. Its faster than stones and more uniform.


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## foody518 (Jan 17, 2017)

Ruso said:


> Convex on wide bevel; Does it even make sense?



Why wouldn't it make sense?


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## Ruso (Jan 17, 2017)

foody518 said:


> Why wouldn't it make sense?



If we are talking about the same, then convex wide bevel will be inherently thicker compared to flat one. Hence will wedge more and better food separation is questionable since wide bevel already provides that.


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## foody518 (Jan 17, 2017)

Ruso said:


> If we are talking about the same, then convex wide bevel will be inherently thicker compared to flat one. Hence will wedge more and better food separation is questionable since wide bevel already provides that.



My thought was - for a given angle right behind the edge, a wide bevel with convex can be a little more acute in the transition up to the shinogi. And maybe potentially help create a less abrupt transition. Like applying single bevel sharpening concepts of moving the shinogi up, then slightly different angle and pressure moving the edge up. Isn't that a slight convex?

But then, if the angle of comparison to be kept the same is the from the shinogi, then yes, the convex version should be thicker behind the edge


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## Nemo (Jan 17, 2017)

On his site, koki describes the Mizuno wide bevel as being sharpened like a single bevel, and it's certainly convexed OOTB.


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## Ruso (Jan 17, 2017)

foody518 said:


> My thought was - for a given angle right behind the edge, a wide bevel with convex can be a little more acute in the transition up to the shinogi. And maybe potentially help create a less abrupt transition. Like applying single bevel sharpening concepts of moving the shinogi up, then slightly different angle and pressure moving the edge up. Isn't that a slight convex?
> 
> But then, if the angle of comparison to be kept the same is the from the shinogi, then yes, the convex version should be thicker behind the edge



I think you are referring to slightly convexing the secondary bevel (edge) only and keeping the primary bevel (wide bevel) flat? And you achieve this by blending both bevels? Am I correct? 

My initial impression was that you suggest to convex the whole primary bevel....?


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## foody518 (Jan 17, 2017)

Ruso said:


> I think you are referring to slightly convexing the secondary bevel (edge) only and keeping the primary bevel (wide bevel) flat? And you achieve this by blending both bevels? Am I correct?
> 
> My initial impression was that you suggest to convex the whole primary bevel....?



Apologies, didn't mean to be confusing, was just thinking about something like this [video=youtube;kA0vdeDDSJI]https://www.youtube.com/watch?v=kA0vdeDDSJI[/video]
As opposed to trying for totally flat from shinogi line to edge


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## Nemo (Jan 17, 2017)

Ruso said:


> I think you are referring to slightly convexing the secondary bevel (edge) only and keeping the primary bevel (wide bevel) flat? And you achieve this by blending both bevels? Am I correct



FWIW think that the Mizuno seems more like this than a convex of the whole wide bevel.


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## XooMG (Jan 17, 2017)

How flat or convex a bevel should be depends largely on the height and thickness of the bevel. I do not strongly agree that the shinogi itself has a massive effect on food separation or release as it pertains to individual cuts. It may limit the effect of climbing pieces that are already stuck to the bevel, but it otherwise is not very effective at mitigating the sticking and lockup that happens within the first 5-15mm of the bevel.

A main benefit of knives with this geometry is that they allow less acute bevels on thinner overall blades, and the overall angle is what produces relevant separation. The separation, if done appropriately, is what mitigates ingredient sticking on the bevel itself.

If the bevel is thin enough at the edge and appropriately thick e-5 to e-10 (5-10mm away from the edge; i.e. the bevel planes are not too acute), a flat can work well. Thinner knives with higher bevels (e.g. <1mm thick @ e-8 to e-10 and shinogi at e-15 or higher) benefit from a less acute geometry from about e-5. Incidentally, one noticeable problem with some knives is that e-5 to e-10 is too thin and ~e-2 is thickish, which even with a zero grind (strong edge convex) feels more like a fat edge with parallel bevels in harder ingredients. These benefit from drawing the convex back a bit by edge-focused thinning, even if they seem reasonably thin already.

I have done a few experiments on this and do not think I'm too far off-base, but please don't take it to be authoritative or overconfident. Apologies for the shorthand...but saying "from the edge" gets tiring.


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## Nemo (Jan 17, 2017)

Thanks Xoo. Does that mean that it essentially depends on the knife and its geometry?


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## XooMG (Jan 18, 2017)

Nemo said:


> Thanks Xoo. Does that mean that it essentially depends on the knife and its geometry?


I think it might feel a bit obfuscatory or discouraging to suggest that every knife is unique, but I think it is good to work with practical principles. Try the knife and see how it handles challenges (bearing in mind sometimes ingredients are very cooperative and give a skewed perception), and adjust what needs adjusting. I have a Wakui wide-bevel that cuts very well overall with a dead-flat bevel. Originally thought I would change it, but using the knife convinced me to leave it alone until it needs more serious thinning.

Best way to know the knife is to just cut stuff with it...and see where it starts to encounter trouble, and what the nature of that trouble is. Not too hard to intuit where changes can be made.


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## Nemo (Jan 18, 2017)

Good advice Xoo.


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## Nemo (Jan 18, 2017)

v647c said:


> Is this the aogami 2 mizuno gyuto?..... since the bevel is quite large, I think a 1k finish will probably not be high enough. You will feel the scratches on many ingredients especially if cutting on an angle.



After cooking tonight, yeah, the Mizuno seems to have lost some of its food releasy goodness with the wide bevel only pllished to 1K. Think I'm gonna run it over a 3k tomorrow and see what difference it makes. Fascinating.


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## foody518 (Jan 18, 2017)

Nemo, do you have a Suehiro Rika?


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## Nemo (Jan 18, 2017)

No. Only Chosera 400, 1k, 3k. Junpaku 8k.

Poloshed wide bevel last time with 3k and result seemed better.


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## hambone.johnson (Jan 18, 2017)

I do not adhere to any specific prescription there. I sharpen intuitively with five conditions: material limits, overall geometry, intended use, available/convenient methods, and personal whim. Usually very subtle double bevel with microconvexing and slight final edge chasing.

This --- it's all subjective, but one of the advantages to pro kitchen use is you get instant feedback. Trial and error on each blade.


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## cheflivengood (Jan 18, 2017)

Also keep in mind that a good amount of food release issues can be cured by knife cutting technique.


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## Nemo (Jan 18, 2017)

cheflivengood said:


> Also keep in mind that a good amount of food release issues can be cured by knife cutting technique.



Yes. I suspect that the reason that I value food release is because I'm not a pro chef and my technique has a lot of room to improve. Know of any resources to help me improve?


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## cheflivengood (Jan 18, 2017)

Nemo said:


> Yes. I suspect that the reason that I value food release is because I'm not a pro chef and my technique has a lot of room to improve. Know of any resources to help me improve?



Not really other than expierement. If its say bell pepper laying flat on a board, the only part of my knife that touches the board is the very tip and I pull straight back. If its a thicker piece of something say butternut squash I never have the tip of the knife and the heel at the same level until it touches the board, I lead with the tip going down and up, kind of like a how you do your hand out of a car window thats moving quite fast, wave like.


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## malexthekid (Jan 18, 2017)

I think some videos would be appropriate.... maybe showing how that thinned maumasi performs


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## cheflivengood (Jan 18, 2017)

malexthekid said:


> I think some videos would be appropriate.... maybe showing how that thinned maumasi performs



I just ordered a iphone tripod so that is a possibility.


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