# How often do you thin?



## eazypeazy (Jul 24, 2017)

Sorry for the first post noob questions. Thinning seems daunting and confusing to me. I've got a typical Henckels (yeah, yeah, I'm working on it) beastly thick chef knife, and I'm wondering when it can be thinned. How often does one thin? Each time they sharpen? Do you thin the whole knife, or just add an increased secondary bevel so it's thinner behind the edge and leave the rest of the knife face alone? When does it "feel" like it's time to thin? Can you thin softer western steels or will their integrity be compromised? Sorry for all the questions. Thanks!


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## icanhaschzbrgr (Jul 24, 2017)

It's a easy question really. When you feel the knife isn't cutting like it used to  time to thin. How often that happens? Depend on the knife and usage. 
Obviously, when the knife was ground very thin behind the edge  it could go on without thinning longer compared to thicker knives. 

When you sharpen knife  you are touching just the very edge (ideally). So over time, as you grind more and more metal away from the edge  it will became thicker. If it still performs nicely  no point to thin. 

But if you aren't happy with performance, and you think it's because of the thickness behind the edge  then you need to thin it. It's a very personal thing actually. What is acceptable for me might not be acceptable for you and vice versa. 

Western knives can be thinned as well, but you need to take into account their softness. If you make them as thin as Japanese makers do  they would cut well, but for a very short period of time. Soft steel won't keep edge for long, it will roll and bend. So over the life of western knife thinning would make a difference towards better cutting, but you shouldn't try to make it as thin as Japanese knives.

I don't thin my knives when I sharpen them, because they are very thin already. But many times I've thinned knives right after purchasing, because their stock geometry was too thick for my taste.


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## K813zra (Jul 24, 2017)

It depends on the knife, for me. Something like my Ginga will get a light thinning behind the edge but on rare occasion as it is already so thing. Knives with wide bevels get thinned every time they see a full sharpening rather than a touch up. Typically I would say that for me thinning should happen any time the bevel is reset. I guess everyone is different, as was said above, though.


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## krx927 (Jul 24, 2017)

I think you can thin your Henckels a bit immediately. It comes way too thick.

I general I find that I need to thin the knife after every 3 to 4 sharpening to keep it in original shape. You can also nicely see the tickens by how big initial bevel is. Usually when you buy a (Japanese) knife the initial bevel is barely noticeable. After a few sharpenings it gets much bigger because the knife becomes thick behind the edge.

But like icanhaschzbrgr wrote, easiest way to spot something is not OK is through performance.


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## Benuser (Jul 24, 2017)

I start every sharpening -- not a touching up -- far behind the bevel, at the lowest angle I'm comfortable with.


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## Mucho Bocho (Jul 24, 2017)

Benuser said:


> I start every sharpening -- not a touching up -- far behind the bevel, at the lowest angle I'm comfortable with.



I'm with Ben (as usual)


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## Nemo (Jul 24, 2017)

Benuser said:


> I start every sharpening -- not a touching up -- far behind the bevel, at the lowest angle I'm comfortable with.



On the same stone that you begin sharpening the edge with or a more coarse stone?

E.g.: if you are sharpening with a 1000, do you thin with a 1000 or say a 400?


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## Benuser (Jul 24, 2017)

Same stone, Naniwa Pro 400 or 800.


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## Dave Martell (Jul 24, 2017)

Always start by hitting the top (shoulder) of the bevel and working your way down to the edge/burr. If you do this each time you do stone work you're thinning as you go. It won't add up to much performance gains but it'll keep your edge thin longer than sharpening it any other way.

Now there's another thinning where you purposely work at much lower angles to actually thin "behind the edge" (which is actually above the edge) to make for performance gains. This can be a little or a whole lot of work - your choice. Some folks do this every time they sharpen.


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## Badgertooth (Jul 24, 2017)

Benuser said:


> I start every sharpening -- not a touching up -- far behind the bevel, at the lowest angle I'm comfortable with.



+ 1


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## Nemo (Jul 24, 2017)

Dave Martell said:


> Always start by hitting the top (shoulder) of the bevel and working your way down to the edge/burr. If you do this each time you do stone work you're thinning as you go. It won't add up to much performance gains but it'll keep your edge thin longer than sharpening it any other way.
> 
> Now there's another thinning where you purposely work at much lower angles to actually thin "behind the edge" (which is actually above the edge) to make for performance gains. This can be a little or a whole lot of work - your choice. Some folks do this every time they sharpen.



If you do option 2, does it turn the blade into a wide(ish) bevel? Do you then follow that widish bevel as a thinning bevel for subsequent sharpenings?


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## brianh (Jul 24, 2017)

I've never thinned, only touched up and sharpened. Anyone care to share any pics? I would think a kurouchi finished blade would be easier to thin visually than say a monosteel carbon. I've seen Jon's videos but good pics would be very useful.


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## Badgertooth (Jul 24, 2017)

Benuser said:


> I start every sharpening -- not a touching up -- far behind the bevel, at the lowest angle I'm comfortable with.



Also, it's essential for natural stones to start the process of slurry generation


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## foody518 (Jul 24, 2017)

Nemo said:


> If you do option 2, does it turn the blade into a wide(ish) bevel? Do you then follow that widish bevel as a thinning bevel for subsequent sharpenings?



How it looks will depend on the thickness and geometry of the knife in question as well as how tentative or aggressive your angle(s)

That is my "thinning bevel" and the primary bevel is tiny


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## Anton (Jul 24, 2017)

Badgertooth said:


> Also, it's essential for natural stones to start the process of slurry generation



May help others, You mean prior to thinning or as a result of the "every" sharpening step


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## labor of love (Jul 24, 2017)

foody518 said:


> How it looks will depend on the thickness and geometry of the knife in question as well as how tentative or aggressive your angle(s)
> 
> That is my "thinning bevel" and the primary bevel is tiny



I was going to post a pic of a gyuto that I do basically the same thing for.


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## v647c (Jul 24, 2017)

If you feel the knife cuts well then there isn't any need to thin it. As others have mentioned, simply removing the "shoulders" of your edge should give you a noticeable performance increase. Creating a thinning bevel that's too defined will result in there being shoulders that could be felt while cutting. I think the best way is to simply blend the edge into the knife by sharpening at the lowest angle after sharpening the actual edge. I feel it's less complicated to do than creating a thinning bevel, and the knife will definitely have an easier time sinking into product.






Wide bevel or convex grind, doesn't matter


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## qjlforever (Jul 24, 2017)

too thin is not good. its lightness,you can not handle it well and do fast job.


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## Badgertooth (Jul 24, 2017)

Anton said:


> May help others, You mean prior to thinning or as a result of the "every" sharpening step



As a result of the "every" sharpening step. Just wrangling with my first cleaver now.. that it had me beat but I got the hang of it now behind the bevel.


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## malexthekid (Jul 24, 2017)

My only problem with the thin at every session is the refinishing required. On a wide bevel it makes sense. But on others not so much for me...


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## WOK-a-holic (Jul 25, 2017)

Thin once when new .
maybe again many year's later if needed . 
usually one time .


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## XooMG (Jul 25, 2017)

I just got used to uglying up my knives so I could regularly thin. I generally favor knives that provide a dedicated thinning and maintenance space. On a recent refinish, I decided to leave a usable stone path, though it might look less appealing than a full polish.


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## Sleep (Jul 25, 2017)

Recently thinned my Itinomonn because it was starting to cut poorly. It'd be the 2nd or 3rd thinning in the year or so I've owned it. And that's my main work knife.


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## krx927 (Jul 25, 2017)

malexthekid said:


> My only problem with the thin at every session is the refinishing required. On a wide bevel it makes sense. But on others not so much for me...



1+

thinning a bit every time you sharpen and not refinishing the knife means you have ugly knives all the time...


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## Benuser (Jul 25, 2017)

With carbons the patina very quickly reappears


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## labor of love (Jul 25, 2017)

If you thin a blade regularly along with sharpening sessions then we're talking about a simple 320-400
Grit stone. Something you can clean up with a mid grit stone potentially, which is the next step in the sharpening progression anyway. Then clean up behind the edge with micro pads or just let it all hang out until next time.


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## Mucho Bocho (Jul 25, 2017)

Ok in this circumstance, I'm defining thinning, as the first step in sharpening a knife. I lower the blade as close as I can without touching the blade face against the stone (3 to 5 degrees or lower), it will leave scratches about 2mm from the edge, but those will be polished out on higher grit stones. No blade face refinishing required.

THINNING can also be performed by laying the knife on the stones and grinding away each side 5 to 10mm up the blade face.

To clarify, when I sharpen I thin every time as part of proper maintenance. Sometimes a knife would benefit from a or multiple THINNING, which as mentioned, requires the blade faces to be refinished. (Carter Muteki).





krx927 said:


> 1+
> 
> thinning a bit every time you sharpen and not refinishing the knife means you have ugly knives all the time...


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## krx927 (Jul 25, 2017)

Benuser said:


> With carbons the patina very quickly reappears





labor of love said:


> If you thin a blade regularly along with sharpening sessions then we're talking about a simple 320-400
> Grit stone. Something you can clean up with a mid grit stone potentially, which is the next step in the sharpening progression anyway. Then clean up behind the edge with micro pads or just let it all hang out until next time.



You are both true but still it does not look same if you properly refinish the knife. But in the future I will start doing it like this regularly = thinning a bit when I sharpen. I really hate when I need to do big thinning.

I tried this 2 weeks ago with my Watanabe 240. It was OK and at the end I forced the patina so it does not look that bad, but still way off what it looked before.


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## foody518 (Jul 25, 2017)

Benuser said:


> With carbons the patina very quickly reappears


On my carbon monosteel knife shown in post #14, the thinned area will patina and not be very perceptibly different than the blade face above it. Of course, factors like vertical vs horizontal grind lines+ your sharpening technique will affect how blended or not this looks


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## Ruso (Jul 25, 2017)

Nemo said:


> If you do option 2, does it turn the blade into a wide(ish) bevel? Do you then follow that widish bevel as a thinning bevel for subsequent sharpenings?



Yep, you are correct in general terms.


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## labor of love (Jul 25, 2017)

krx927 said:


> You are both true but still it does not look same if you properly refinish the knife. But in the future I will start doing it like this regularly = thinning a bit when I sharpen. I really hate when I need to do big thinning.
> 
> I tried this 2 weeks ago with my Watanabe 240. It was OK and at the end I forced the patina so it does not look that bad, but still way off what it looked before.


Yeah, that's the idea of a thinning bevel for me. I'm thinning every time I sharpen until I'm happy with how the blade cuts. Between sharpening sessions I do minimal cosmetic things until the edge and shoulders are how I want them. I'm not really interested in comepletely refinishing the blade until the thinning work is complete. And by refinishing I mean several grits of auto sand paper and then lots of time with micro pads. It just doesn't make sense to deal with all that stuff over and over again every time I thin a knife.


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## Choppin (Jul 25, 2017)

How exactly does thinning play out in convex bevels? From where I stand, there are 2 possible scenarios (without taking the effort to flatten the bevel): 1) lower the angle to get to the area immediately behind the edge or 2) lower the angle even more to work on the shoulders (here my bevel is laying flat on the stones). Do you guys usually do one of these, or both?


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## loong (Jul 25, 2017)

Choppin said:


> How exactly does thinning play out in convex bevels? From where I stand, there are 2 possible scenarios (without taking the effort to flatten the bevel): 1) lower the angle to get to the area immediately behind the edge or 2) lower the angle even more to work on the shoulders (her my bevel is laying flat on the stones). Do you guys usually do one of these, or both?



I do both scenarios, start with your second scenario on medium to fine grid stones and finish with your first scenario with a few strokes on very fine stones.


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## eazypeazy (Jul 25, 2017)

Wow, great responses so far. Thanks so much for the insight. Choppin posted a good question about convex bevels - anyone have any input? Also can you a knife that has a standard bevel (not sure what the name would be for 'standard') a concave bevel, ie, my henckles?


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## K813zra (Jul 25, 2017)

Choppin said:


> How exactly does thinning play out in convex bevels? From where I stand, there are 2 possible scenarios (without taking the effort to flatten the bevel): 1) lower the angle to get to the area immediately behind the edge or 2) lower the angle even more to work on the shoulders (her my bevel is laying flat on the stones). Do you guys usually do one of these, or both?



You took out all of my fun as I was going to say flatten them...That really is what I would do though.


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## foody518 (Jul 25, 2017)

eazypeazy said:


> Wow, great responses so far. Thanks so much for the insight. Choppin posted a good question about convex bevels - anyone have any input? Also can you a knife that has a standard bevel (not sure what the name would be for 'standard') a concave bevel, ie, my henckles?



What Henckels do you have that it has a concave bevel?


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## naifu (Jul 26, 2017)

Murry Carter has a video on [video=youtube;UdEe9sEQRcE]https://www.youtube.com/watch?v=UdEe9sEQRcE[/video].

Does one sharpen the edge first, then thin? Does the order matter? It seems like working on the edge first would be the right order, because then you can determine how much to thin behind the edge.


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## krx927 (Jul 26, 2017)

No, it's juts the opposite, first thin and then do the cutting edge.


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## Choppin (Jul 26, 2017)

loong said:


> I do both scenarios, start with your second scenario on medium to fine grid stones and finish with your first scenario with a few strokes on very fine stones.



That makes sense... probably a way to thin while maintaining the convexity (to some extent)




K813zra said:


> You took out all of my fun as I was going to say flatten them...That really is what I would do though.



I guess you would have to do that at some point, certainly when you need to do more serious thinning. But probably the 2-step process outlined above would delay that need for serious thinning and maintain the convexity until then? Just thinking out loud here...

I watched that Carter video but I have never seen anyone actually sharpening kitchen knives with that sweeping motion


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## Benuser (Jul 26, 2017)

Any sharpening at lower angle than the very edge is thinning.
Removing a shoulder is thinning, but go on, until you reach the very edge and raise a burr on the opposite side. Or establish the final edge little before.
Verify the scratch pattern or use the marker trick to see how far you have come.
When thinning you use some finger pressure on the opposite side. 
When you're concerned about the blade's appearance, don't. It will take much longer, you won't get a nicely convexed bevel, but you still may remove a lot of steel and improve performance. In that case keep your flat stone free from any mud.


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## trilby (Jul 26, 2017)

Any recommendations for youtubers that cover the thining well?


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## Leo Barr (Jul 18, 2019)

eazypeazy said:


> Sorry for the first post noob questions. Thinning seems daunting and confusing to me. I've got a typical Henckels (yeah, yeah, I'm working on it) beastly thick chef knife, and I'm wondering when it can be thinned. How often does one thin? Each time they sharpen? Do you thin the whole knife, or just add an increased secondary bevel so it's thinner behind the edge and leave the rest of the knife face alone? When does it "feel" like it's time to thin? Can you thin softer western steels or will their integrity be compromised? Sorry for all the questions. Thanks!


99% of the time I thin behind the edge every time the height of the knife reduces from sharpening the edge the knife becomes thicker - if a knife is to cut deep then it needs a fine entry big shoulders wedge destroy the food & flavor .many knives are finished on big wheels so there are often hollows in the blade so these will go over consecutive thinning .
Initially the finish is not great unless you have hours to spend but over time the finish can be better than new once the hollows are gone then the thinning is easy since it is just maintaining it like the edge.
Western knives do not need such a wide thinning bevel so a thinning bevel of 2-3mm wide seems good on a Wūstof .
Overall you are trying to maintain or improve the thickness out of the box this is why I hate having to sharpen knives which have seen heavy steel use since this opens up all sorts of issues - tips -heels-hollows -scratches-thickening-it’s not uncommon to see Shuns where the hagane is almost invisible due to the thickness of the blade.


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## Benuser (Jul 18, 2019)

You may use the long side of the stone when thinning. Reduces scratches to the lower part of the face. Very simple but most useful trick I got here.


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## Benuser (Jul 18, 2019)

A few figures I tend to aim for: 0.2mm thickness behind the edge, 0.5 at 5mm up to the spine, 1mm at 10mm. For general purpose chef's, not for lasers. 
You can easily get an idea by locking the micrometer at 0.5/1mm and see where along the blade it glides through it. Start at the tip.


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## krx927 (Jul 18, 2019)

Benuser said:


> You may use the long side of the stone when thinning. Reduces scratches to the lower part of the face. Very simple but most useful trick I got here.



Good tip! You can also tape the part that you do not want to thin.

How do you make the stone stand on the side while thinning using the method you suggested?


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## Benuser (Jul 18, 2019)

krx927 said:


> Good tip! You can also tape the part that you do not want to thin.
> 
> How do you make the stone stand on the side while thinning using the method you suggested?


Sorry if I wasn't clear. This is what I mean.


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## krx927 (Jul 18, 2019)

clear now.


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## Benuser (Jul 18, 2019)

trilby said:


> Any recommendations for youtubers that cover the thining well?



Jon Broida's 
https://www.youtube.com/playlist?list=PLEBF55079F53216AB


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## ian (Jul 18, 2019)

Benuser said:


> A few figures I tend to aim for: 0.2mm thickness behind the edge, 0.5 at 5mm up to the spine, 1mm at 10mm. For general purpose chef's, not for lasers.
> You can easily get an idea by locking the micrometer at 0.5/1mm and see where along the blade it glides through it. Start at the tip.



I really appreciated it when you shared these figures in a thread of mine a while ago. Makes a real difference having a metric benchmark to aim for when you’re starting out, rather than having you rely on a “feel” that you haven’t developed enough to be completely confident in.


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## Benuser (Jul 18, 2019)

ian said:


> I really appreciated it when you shared these figures in a thread of mine a while ago. Makes a real difference having a metric benchmark to aim for when you’re starting out, rather than having you rely on a “feel” that you haven’t developed enough to be completely confident in.


Thanks!


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## panda (Jul 18, 2019)

i thin a little bit every single time i sharpen. like 5-10 minutes worth


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## inferno (Jul 18, 2019)

eazypeazy said:


> Sorry for the first post noob questions. Thinning seems daunting and confusing to me. I've got a typical Henckels (yeah, yeah, I'm working on it) beastly thick chef knife, and I'm wondering when it can be thinned. How often does one thin? Each time they sharpen? Do you thin the whole knife, or just add an increased secondary bevel so it's thinner behind the edge and leave the rest of the knife face alone? When does it "feel" like it's time to thin? Can you thin softer western steels or will their integrity be compromised? Sorry for all the questions. Thanks!



I thin all my knives when new. i basically flatten the sides when new. since these are always concave. other than that i have so many knives I kinda doubt i will ever need to thin any one of them ever again in my entire life.


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## Nemo (Jul 18, 2019)

panda said:


> i thin a little bit every single time i sharpen. like 5-10 minutes worth


I assume you only do this if going to a medium stone, not with a touch up on a fine stone?


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## panda (Jul 18, 2019)

Nemo said:


> I assume you only do this if going to a medium stone, not with a touch up on a fine stone?


yea chosera 400. i dont bother with 'touchups' any more. i just do cho400 and aizu progression when ever edge wont come back with a few swipes on mac black.


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## inferno (Jul 18, 2019)

herecy!!!! mac black...


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## Byphy (Jul 24, 2019)

How many passes on a 400 grit would suffice for proper thinning (lets say for an Ashi 180mm wa-petty)? As a noob, its difficult for me to look at the geometry of a blade and know what I’m seeing.

Any advice as to actually being able to see thinning progress would help. 

Watching Jon’s videos, he said “Go slow. You can take metal off, but can’t put metal back on”. Makes it intimidating haha. So I want to learn to thin properly without ruining my knives.

Thanks


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## panda (Jul 24, 2019)

cut something with it every 10 minutes to feel the progress


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## Kippington (Jul 25, 2019)

Byphy said:


> Go slow. You can take metal off, but can’t put metal back on


This is true, but keep in mind that thinning by hand is an inherently slow process - it's not like you're removing loads of metal with each pass on the stone.
Read 'go slow' as moving deliberately and accurately, rather than counting each pass through fear of grinding a large chunk off your knife.


Byphy said:


> How many passes on a 400 grit would suffice for proper thinning (lets say for an Ashi 180mm wa-petty)?


How long is a piece of string?


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## Carl Kotte (Jul 25, 2019)

Kippington said:


> How long is a piece of string?



17


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## refcast (Jul 25, 2019)

How to 'see' thinning with eyes and fingertips

(1) The easiest way to see thinning is to thin at the heel, where you can see the choil. See where the knife gets thinner, or the curve changes shape. Then try to repeat what you did along the rest of the blade. This is how I started out.

The ashi ginga has a very consistent convex grind, so this should be representative of how it will likely cut. Sometimes, the choil is actually very very slightly thinner than the cross section of the knife right after the choil. This is pretty common in knives I've bought, due to how they are made. Also there may be very very tiny 'overgrinds' that are slight concavities. This again, is common and can come out with thinning. And of course, the choil could not very well describe how the knife may be like towards the tip. The choil also does not describe the grind of the part above the choil, the blade face, which does play a role in food release, but next in line compared to near the edge, and the middle of the blade.

(2) I also check with my fingertips move from spine to edge. This tells me how smoothly the knife will go through the cut, because this is how smooth the grind is. A sudden jump can be good for food release, but by far for non-wide bevel knives like the Ginga, I like the smoother cut. When you do this, you can wet the blade a little if it helps, to help your fingers glide.

(3) I check the thickness at the same distance from the edge along the entire length of the blade. I repeat for each distance from the edge. This is most critical right above the edge, which is the thinness that determines how easily the knife sinks (sometimes viciously) into food. Note that distal taper also comes into play, and the edges near the tip are often thinner than near the heel. This isn't necessary, it's just a built in feature because some people like thin tips to go through dense things that thicker tips get stuck in, and people like a little thicker heels for food release and a confident feel when bashing there.

(4) The hardest is to check the blade in light to see the contouring of the knife. This is hard because the blade will have the thinning marks, which makes things difficult. Training the eye to 'see' curves takes a while. What I can say is that convex will bend an image one way and concave will bend it another way.

How many passes for a ginga on a 400? 

I guess start with 10 swipes (back and forth = 1) on each side, right behind the edge. Then resharpen as normal on a higher grit stone. Cut, and repeat for more "performance", or less resistance going through food. If the surface finish is kinda grabby, you can polish that out with a higher grit stone, sandpaper, bar keeper's friend, or metal polish (though this doesn't help much with deep scratches).

"Proper" is up to how little resistance you like, and how confident feeling you want the knife. Or if the edge bends or chips or crumbles. I do have a ginga as well, and I've found an optimum edge thinness, and more than that the edge starts to bend a bit after going through certain foods. I could try again, though, or thin higher up the blade.


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## Byphy (Jul 25, 2019)

Oh wow, thank you for such a detailed post! @refcast


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