# sharpening the tip of a knife



## noj (Aug 5, 2022)

I have a question on sharpening the tip of a knife. Both videos show lifting up
the end of the knife a bit. I am not sure why one video shows rotating the knife 
towards the spine, and the other shows rotating away from the spine. By 
"rotation towards the spine" (using Jon's terminology) means turning the wrist to
lower the spine towards the stone; decreasing the angle on the wrist axis.

I can see the overall technique isn't exactly the same, but I don't have an 
explanation for the disparity yet.

Jon's (JKI) video - rotation towards the spine:


Peter's (Knifeplanet) video - rotation away from the spine:


Any ideas? Thanks in advance!


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## Pie (Aug 5, 2022)

I can’t really put it into words, but I don’t really focus on lifting or dropping the spine when sharpening the tip.. it’s more of a smooth following of the curve to the tip. 

If you put the knife flat on its side and push down on the bevel near the tip, kinda roll the pressure back and forth - the handle will pop up and follow a curve as you roll. That’s theoretically the same curve, just at a lower angle. Raise that angle a bit to hit the edge. Note that this will be easier with a shorter knife.


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## tostadas (Aug 5, 2022)

Think of the belly of the knife sort of like a round dinner plate. Try to hold that plate at lets say a 45degree angle against your stone for simplicity. Now rotate the plate to a different part of the edge, maintaining the angle between the plate and the flat surface. Pay attention to how you need to adjust in order to keep the angle consistent. It's the exact same concept when you think about the round part of your blade.

You can also tape a handle onto the plate and play around with how your wrist shifts depending on the part of the curved plate you want to "sharpen"


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## McMan (Aug 5, 2022)

@Pie and @tostadas (cool example of paper plate!) explain it well.
Without lifting/rocking the handle a bit to sharpen the tip, the bevel at the tip would get fatter than elsewhere on the knife, which Jon points this out, or even, with successive sharpenings, would lose the arc and assume a flat profile, or worse, a bird's beak.
Both videos show lifting the handle to sharpen the tip. I think perhaps this is more an issue of language/description than technique?


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## MrHiggins (Aug 5, 2022)

I think the Sharpee trick will be your friend here. For me, if I don't lift and rotate to a less accute angle as I get toward the tip, I don't get good tip sharpening results. The Sharpee will show you exactly where your knife is hitting the stone.


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## noj (Aug 5, 2022)

If you look carefully at both videos, the rotation angles are exactly opposite. Jon uses a less acute angle at the tip, and Knifeplanet shown a more acute angle. 

Check this exact time for the more acute angle:


Check this exact time for the less acute angle "rotation towards the spine":


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## HumbleHomeCook (Aug 5, 2022)

Yep, use a marker.


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## noj (Aug 5, 2022)

MrHiggins said:


> I think the Sharpee trick will be your friend here. For me, if I don't lift and rotate to a less accute angle as I get toward the tip, I don't get good tip sharpening results. The Sharpee will show you exactly where your knife is hitting the stone.


I have used a marker, but I can't see anything useful. The bevel is narrow enough, than unless I am way way off, even a light pass scrapes the marker away evenly as far as I can see.


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## noj (Aug 5, 2022)

tostadas said:


> Think of the belly of the knife sort of like a round dinner plate. Try to hold that plate at lets say a 45degree angle against your stone for simplicity. Now rotate the plate to a different part of the edge, maintaining the angle between the plate and the flat surface. Pay attention to how you need to adjust in order to keep the angle consistent. It's the exact same concept when you think about the round part of your blade.
> 
> You can also tape a handle onto the plate and play around with how your wrist shifts depending on the part of the curved plate you want to "sharpen"


That was the first thing I tried. The addition of the raising the end of the knife complicated the geometry to the point I couldn't draw any conclusions. 

If I don't raise the end of the knife, it suggests "rotation towards the spine" is correct, since there is no other way to reach the edge. That said, I seem to get bad results (seems like over rotation per JKI video) doing so. I get much the same with no rotation. I am using shape/patterns in the metal, since I can't get the magic marker to tell me much.


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## noj (Aug 5, 2022)

Pie said:


> I can’t really put it into words, but I don’t really focus on lifting or dropping the spine when sharpening the tip.. it’s more of a smooth following of the curve to the tip.
> 
> If you put the knife flat on its side and push down on the bevel near the tip, kinda roll the pressure back and forth - the handle will pop up and follow a curve as you roll. That’s theoretically the same curve, just at a lower angle. Raise that angle a bit to hit the edge. Note that this will be easier with a shorter knife.


At the moment, I started doing this ("smooth following of the curve to the tip"). But, I would like a better understanding of what is going on. I don't want to find out (the hard way) that the smooth motion was pushing things in the wrong direction.


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## Ochazuke (Aug 5, 2022)

Different stokes for different folks.  But you could always just ask the man @JBroida himself (especially considering that he's a forum member).


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## Naftoor (Aug 5, 2022)

What I’ve been working on recently, is watching the edge as it contacts the stone. This is easier when sharpening towards yourself, but I’ve done it in both directions. I scrub for thinning and for chip removal, and use edge leading sweeps for everything after that. 

When I watch how the edge contacts the stone through the stroke, my arms seem to have an easier time matching the angle as I transition into the belly and tip sections. Definitely not the best sharpener out there, I can pretty cleanly slice through paper towels now but I still can’t really get a clean push cut so take my advice with a grain of salt. 

I saw a video, I believe from neeves that mentioned when sharpening, to lock your wrists, and as you reach the belly to use your elbows only to change the elevation. He mentioned that it helps lock in the angle. I haven’t tested that, but if I find the video I’ll share it


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## MowgFace (Aug 5, 2022)

Can you post a picture of the knife in question? Or if you are just asking for general technique, at least seeing what your current tips are looking like.

I know a properly sharpened tip and heel took me the longest to "figure out"


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## noj (Aug 5, 2022)

I'll do both;-) I was looking for a reason behind the apparent contradiction, and the general technique. At the same time, I'll see if I can take pictures, though it isn't about a single knife.


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## noj (Aug 6, 2022)

Photos will be delayed. I tried a cell phone, and an older digital camera, but neither one is able to resolve that level of detail and close-up. I'll have to look into a USB microscope.

On a very positive note, I got a phone call from Jon (at JKI).


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## noj (Aug 6, 2022)

Here is a thought experiment, and pictures. First, as perhaps an
oversimplification, imagine your control of the knife is on just two
axis: your wrist (rotation angle along the axis of your knife handle),
and your wrist height. Of course, the human body is more complicated,
but let's focus on these because they are the primary ones involved.

Here is my model of a knife. Note the bevel angle is constant.
At any point along the curve of the "blade", the position of the
knife and handle isn't in question (assuming you want a constant 
bevel angle).





Here is the position when grinding along (what would normally be) the
flatter part of the knife. Note the wrist angle and height.




Here is the position when grinding as you start getting into the curve
approaching the tip. Note the wrist angle and height. The angle is
decreased, and the height is increased. Again, by angle I mean 
rotation angle along the axis of your knife handle, err paint stick;-)
The edge angle is constant (as determined by my junky plastic plate).





Still not sure? Let's push it to a (probably unrealistic) position
where the blade bends a full 90 degrees. The angle is now zero.




I conclude that under the assumption that we maintain a constant bevel
angle, and have two means of control (rotation angle along the axis 
of your knife handle, and handle height), you must raise the handle
and rotate to a lower angle.


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## noj (Aug 7, 2022)

tostadas said:


> Think of the belly of the knife sort of like a round dinner plate. Try to hold that plate at lets say a 45degree angle against your stone for simplicity. Now rotate the plate to a different part of the edge, maintaining the angle between the plate and the flat surface. Pay attention to how you need to adjust in order to keep the angle consistent. It's the exact same concept when you think about the round part of your blade.
> 
> You can also tape a handle onto the plate and play around with how your wrist shifts depending on the part of the curved plate you want to "sharpen"


I found a plate with a bevel at the edge to do this. I think the breakthrough was (as you said) to let the plate/bevel provide the answer, rather than fiddle with the inputs and watch what the plate did. Once you realize that in order to maintain a constant angle, there is one and only one position (excluding of course a theoretical 360 degree horizontal rotation around the point of contact), you have an answer. How you do physically or explain it may be more complicated, but the geometry is now clear. Check out the results I posted. Thanks for the input.


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## sansho (Aug 8, 2022)

thanks, @noj. good posts.

i'll just add this for completeness


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## noj (Aug 8, 2022)

sansho said:


> thanks, @noj. good posts.
> 
> i'll just add this for completeness
> 
> View attachment 192253


Thanks for including this. I keep one of those printed out with my sharpening supplies, though it's pretty much imprinted in my head - not a tattoo ;-) 

I don't have a camera good enough to resolve the marker yet (still investigating). Just looking at the scratch/polishing marks, I find it hard to be sure I can tell the difference between over-rotation and lifting up too much, at least when the mistake is small.

That said, the right hand side looks spot on, but I suspect a bit of lifting up too much on the left side (tip). There's just a bit of shiny rounding/convexity of the bevel at the tip. I suspect that would be the result of lifting up too much vs over-rotation. It might take a sharpening or two to see the results. I don't feel a need to waste metal just for this.


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## M1k3 (Aug 8, 2022)

noj said:


> Thanks for including this. I keep one of those printed out with my sharpening supplies, though it's pretty much imprinted in my head - not a tattoo ;-)
> 
> I don't have a camera good enough to resolve the marker yet (still investigating). Just looking at the scratch/polishing marks, I find it hard to be sure I can tell the difference between over-rotation and lifting up too much, at least when the mistake is small.
> 
> That said, the right hand side looks spot on, but I suspect a bit of lifting up too much on the left side (tip). There's just a bit of shiny rounding/convexity of the bevel at the tip. I suspect that would be the result of lifting up too much vs over-rotation. It might take a sharpening or two to see the results. I don't feel a need to waste metal just for this.


Next time you sharpen, start on the left side. See if your results are better.


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## mpier (Aug 8, 2022)

If you really want to practice tip work get a cheap butcher knife, once you have mastered that the rest is easy.


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## noj (Aug 8, 2022)

mpier said:


> If you really want to practice tip work get a cheap butcher knife, once you have mastered that the rest is easy.


Tried that on an old Sabatier chef's knife. The metal is so soft that I had to use 25+ degrees per side to get something (almost) stable, and easily bends side to side anywhere near the tip. Thanks for the idea though.


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## mpier (Aug 8, 2022)

noj said:


> Tried that on an old Sabatier chef's knife. The metal is so soft that I had to use 25+ degrees per side to get something (almost) stable, and easily bends side to side anywhere near the tip. Thanks for the idea though.


The idea though is just to get used to that big swooping curve and not flatten it out or lay down the angle after that the rest comes easy


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## Delat (Aug 9, 2022)

The main belly of the blade I do standard back and forth motions. But when I get to the curve leading to the tip, I switch to a stropping-style motion for the last few inches leading to the tip. I used to overthink it and initially tried to stick with the traditional back and forth, but since I started just relaxing and letting my natural instincts take over, I’m able to hit the bevel quite well.

Give it a try and see if it works for you - I think we have a natural instinct for following a curve. The arm will naturally rise and the wrist will rotate (towards the spine ) as you follow the curve of the edge. On a pull stroke you start at your typical angle for the flat and pull up and away, and a push is the reverse. Starting and finishing at your normal angle helps you to index and maintain consistency.

I’ve noticed these strokes aren’t as productive (don’t remove as much metal) as straight back and forth - probably because I’m applying less pressure and/or because it’s across a larger surface area - so this part of sharpening takes a little longer for me than the belly.


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## noj (Aug 9, 2022)

Delat said:


> The main belly of the blade I do standard back and forth motions. But when I get to the curve leading to the tip, I switch to a stropping-style motion for the last few inches leading to the tip. I used to overthink it and initially tried to stick with the traditional back and forth, but since I started just relaxing and letting my natural instincts take over, I’m able to hit the bevel quite well.
> 
> Give it a try and see if it works for you - I think we have a natural instinct for following a curve. The arm will naturally rise and the wrist will rotate (towards the spine ) as you follow the curve of the edge. On a pull stroke you start at your typical angle for the flat and pull up and away, and a push is the reverse. Starting and finishing at your normal angle helps you to index and maintain consistency.
> 
> I’ve noticed these strokes aren’t as productive (don’t remove as much metal) as straight back and forth - probably because I’m applying less pressure and/or because it’s across a larger surface area - so this part of sharpening takes a little longer for me than the belly.


Actually, I've been trying this more lately. The straight back and fourth worried me because if there's much curvature, you only have a single point of contact with the stone.

Starting and finishing at my normal angle (and hence not starting at the tip) might be something to focus on. Right now, I have been using deliberate single stroke (edge following, or leading) just to get the "muscle memory" in place. Do you mostly work the last few inches with push/pull and edge on stone the whole time? I can imagine switching up a bit for burr removal.


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## Delat (Aug 9, 2022)

noj said:


> Actually, I've been trying this more lately. The straight back and fourth worried me because if there's much curvature, you only have a single point of contact with the stone.
> 
> Starting and finishing at my normal angle (and hence not starting at the tip) might be something to focus on. Right now, I have been using deliberate single stroke (edge following, or leading) just to get the "muscle memory" in place. Do you mostly work the last few inches with push/pull and edge on stone the whole time? I can imagine switching up a bit for burr removal.



Yup I distorted the curve doing it the traditional back and forth way when I was first learning, so that was a big impetus for me to change.

I keep the edge on the stone and just go back and forth. Then for deburring I do all edge leading, heel to tip.


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## noj (Aug 9, 2022)

Delat said:


> Yup I distorted the curve doing it the traditional back and forth way when I was first learning, so that was a big impetus for me to change.
> 
> I keep the edge on the stone and just go back and forth. Then for deburring I do all edge leading, heel to tip.


This seems to be working for me. I'll need some more practice to get the feel for right vs left hand sides, but it's looking much better.

I also think I know more about what I was doing wrong. I misdiagnosed lifting up too much as over-rotation. The bad part of that is when you rotate less (or not at all), you have to life even higher in order to follow the curve;-) I won't do that again!


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## tostadas (Aug 9, 2022)

Delat said:


> The main belly of the blade I do standard back and forth motions. But when I get to the curve leading to the tip, I switch to a stropping-style motion for the last few inches leading to the tip. I used to overthink it and initially tried to stick with the traditional back and forth, but since I started just relaxing and letting my natural instincts take over, I’m able to hit the bevel quite well.
> 
> Give it a try and see if it works for you - I think we have a natural instinct for following a curve. The arm will naturally rise and the wrist will rotate (towards the spine ) as you follow the curve of the edge. On a pull stroke you start at your typical angle for the flat and pull up and away, and a push is the reverse. Starting and finishing at your normal angle helps you to index and maintain consistency.
> 
> I’ve noticed these strokes aren’t as productive (don’t remove as much metal) as straight back and forth - probably because I’m applying less pressure and/or because it’s across a larger surface area - so this part of sharpening takes a little longer for me than the belly.


Great tip this is what I do too for the belly. It reduces chances of random flat spots on the curve from going back and forth in the same location too much.


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## Desert Rat (Aug 11, 2022)

I like to use old hunting knifes to practice on. They are good and thick and have curved blades. Can be had for next to nothing at yard sales, and most haven't seen a stone in a decade or two. I don't put them on stones that are really fast or that makes any sense. Nope, drag it on out for some hours or over a couple of sessions on some medium grit thing.
One or two of them a year and everything just kind of goes on auto pilot with muscle memory, elbow raises with the curve of the blade.

It's probably sick and wrong but that's what I do.


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## deltaplex (Aug 11, 2022)

I respect this even if I think it's insane.


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## MowgFace (Aug 11, 2022)

All great tips above.

I could also recommend picking up a Masahiro Carbon Gyuto from Amazon for ~50 bucks and use that as your knife work guinea pig.

Wanna try rounding your choil? Masahiro! Thinning? Masahiro! Re-tip? Masahiro! Western to WA conversion? Masahiro!

A lot of my early sharpening was on crappy cheap steel, and while it provided some reps and experience, wasnt 100% translatable to quality steel. While i think the Masahiro is softer, in the 58-59 range I think its darn close to what you could expect from harder Japanese knives.

I dont have any experience with the Fujitora Molybdenum line, sometimes called Fuji Narihara (Made by Tojiro Parent Co) but $34 for a 240 gyuto to sacrifice to science ain't too bad.


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## noj (Aug 11, 2022)

MowgFace said:


> All great tips above.
> 
> I could also recommend picking up a Masahiro Carbon Gyuto from Amazon for ~50 bucks and use that as your knife work guinea pig.
> 
> ...


I'll consider your suggestions, thanks. My current "practice" knife is an old Sabatier chef's knife. I bought this brand new when I was about 18. Post your estimates of my age elsewhere;-) The steel is very soft. I can get a burr by looking at it, and bends pretty easy side-to side.


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## HumbleHomeCook (Aug 11, 2022)

It may just be the light and/or this may be what kicked off your inquiry, but in that picture, the belly looks like you've indeed been too flat.


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## noj (Aug 11, 2022)

HumbleHomeCook said:


> It may just be the light and/or this may be what kicked off your inquiry, but in that picture, the belly looks like you've indeed been too flat.


It's a bad photo. I tried to capture the edge, but all I got was light glare (and adjacent lit-up pixels). Actually, I originally had the handle too high, and almost no rotation. After adjusting my technique, it looked pretty good (checked using a magic marker). With the marker removed, I haven't ground away all the evidence. I'll do that either over time, or if I have nothing better to do;-)


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## Benuser (Aug 11, 2022)

There's a lot of variety in tips amongst vintage Sabs, from Sheffield-like spear points to much more obtuse ones, with a late upswing, which seems the most common. From the point of view on the photo I find it hard to see. It looks like it's in the first category.


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## Desert Rat (Aug 11, 2022)

I know lots of people deburr with edge leading strokes, I do.

I'm not criticizing this guy in the video or anyone that takes edge leading strokes like this.
But for me the tips or point of my knifes improved when I learned to stop on the stone rather than flick the tip off of the stone.


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## Benuser (Aug 11, 2022)

Desert Rat said:


> I know lots of people deburr with edge leading strokes, I do.
> 
> I'm not criticizing this guy in the video or anyone that takes edge leading strokes like this.
> But for me the tips or point of my knifes improved when I learned to stop on the stone rather than flick the tip off of the stone.



Quite sure the tip will end far too high. And the heel section is being neglected.


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## noj (Aug 11, 2022)

Benuser said:


> There's a lot of variety in tips amongst vintage Sabs, from Sheffield-like spear points to much more obtuse ones, with a late upswing, which seems the most common. From the point of view on the photo I find it hard to see. It looks like it's in the first category.


It's also due to years of use and abuse;-) The tip was well rounded over from the years I didn't pay much attention to sharpening skills. Anyhow, I recently removed about 1/2 inch off the tip, re-ground the profile and then primary bevel (both near the tip) so it was evenly thin behind the edge, and decided it was a great time to learn how to do the tips better. I think I made the knife more pointy than it was as new.


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## noj (Aug 11, 2022)

Benuser said:


> Quite sure the tip will end far too high. And the heel section is being neglected.


From my picture, or the video?

I can tell you my photo is awful. Between the glare distortions, multiple bright lights (and shadows in reflections between), I don't even recognize what that's a picture of;-)


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## sansho (Aug 12, 2022)

what i've been doing lately is rotating the whole knife in-plane and keeping the tangent of the bevel's curve at the same position. slower, but i feel like i've been getting more consistent results.


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## jwthaparc (Aug 12, 2022)

The way I always explain this is as follows. 

Take the knife and set it on its edge like you would when you cut something. Now rock the knife, and going from heel to tip. Now take the knife, and angle it like you would when sharpening, and do the same rocking motion. 

That's what you should be doing when sharpening the tip. Raising, or lowering the spine shouldn't really be happening ideally. Unless you are purposely changing the angle you are sharpening at going from heel to spine.

I usually describe what I just said in person so I can give a visual example of rocking the knife. I hope what I mean is coming through.


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## Delat (Aug 12, 2022)

noj said:


> From my picture, or the video?
> 
> I can tell you my photo is awful. Between the glare distortions, multiple bright lights (and shadows in reflections between), I don't even recognize what that's a picture of;-)



The video - if you watch carefully you’ll notice the heel spends almost no time on the stone vs the rest of the edge. With both blade faces he starts the heel on the right side of the stone and immediately pulls it off to the same right side.


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## Benuser (Aug 12, 2022)

noj said:


> From my picture, or the video?
> 
> I can tell you my photo is awful. Between the glare distortions, multiple bright lights (and shadows in reflections between), I don't even recognize what that's a picture of;-)


The video.


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## Benuser (Aug 12, 2022)

noj said:


> It's also due to years of use and abuse;-) The tip was well rounded over from the years I didn't pay much attention to sharpening skills. Anyhow, I recently removed about 1/2 inch off the tip, re-ground the profile and then primary bevel (both near the tip) so it was evenly thin behind the edge, and decided it was a great time to learn how to do the tips better. I think I made the knife more pointy than it was as new.


The removed 0.5" explains a lot. Quite a drastic measure: not only because of the length loss, but as well because of the distal taper: the flimsy tip of a Sab is a characteristic feature. An overly rounded tip may not be that appealing, but still is perfectly functional.


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## natto (Aug 12, 2022)

sansho said:


> what i've been doing lately is *rotating the whole knife in-plane *and keeping the tangent of the bevel's curve at the same position. slower, but i feel like i've been getting more consistent results.


I learned sharpening that way, and never changed. The picture was easy enough to understand to me. Like @noj showed in this post:




noj said:


> Here is a thought experiment, and pictures. First, as perhaps an
> oversimplification, imagine your control of the knife is on just two
> axis: your wrist (rotation angle along the axis of your knife handle),
> and your wrist height. Of course, the human body is more complicated,
> ...



Your thread got me thinking through this lifting and rotating.

With curved tips, like on a rocking knife, rotating in a plane needs a wide sweep of the handle. Rotating and lifting should need less movement of the handle. And this wide sweep does not improve my consistency. Keeping the angle needs attention with unusual movements.

Rocking and lifting is the other way round. Without an idea, how much to rotate and lift, my attention is on the feel. I got to check it out.

Great thread, and thank you @noj.


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## noj (Aug 12, 2022)

natto said:


> I learned sharpening that way, and never changed. The picture was easy enough to understand to me. Like @noj showed in this post:
> 
> 
> 
> ...


You're welcome;-)

A first step (for the way I think about things) was to understand the physics and geometry. The next step (for the way I think about things) is technique and results. That incudes both the (less than theoretical) horizontal rotation around the point of contact, moving point of contact, human ergonomics, and individual preferences. I think I have a good start on a method; I'll have to see what I can do with it.
---------------- self-quote ---------------
"Once you realize that in order to maintain a constant angle, there is one and only one position (excluding of course a theoretical 360 degree horizontal rotation around the point of contact), you have an answer. How you do [it] physically, or explain it may be more complicated, but the geometry is now clear."


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## noj (Aug 12, 2022)

Benuser said:


> The removed 0.5" explains a lot. Quite a drastic measure: not only because of the length loss, but as well because of the distal taper: the flimsy tip of a Sab is a characteristic feature. An overly rounded tip may not be that appealing, but still is perfectly functional.


Drastic, I know, but one of the fun things about getting some new knives can be getting permission to go and fix your old one(s). I have already done a lot of work on that old Sabatier, but that's a story for another day.


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## noj (Sep 14, 2022)

I tried the two basic methods described here. Specifically, lifting/rotating vs sweeping (for lack of better name). I seem to get good results with both. My confidence improved a lot when I could get fast feedback on an inexpensive knife. I used by old Sab. It only too a couple strokes, and I could watch the tip go from too-much-rotation to spot-on (after I reduced rotation, and raised the handle to compensate). The hard part is getting the intuition or muscle memory about the balance between the two (lifting/rotating). I'll have to play around more with the sweeping method; it's just a little harder to know what aspect(s) to correct if it doesn't come out right. Anyhow, I'll keep playing with my poor old Sab when I have time.


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## Benuser (Sep 14, 2022)

noj said:


> Tried that on an old Sabatier chef's knife. The metal is so soft that I had to use 25+ degrees per side to get something (almost) stable, and easily bends side to side anywhere near the tip. Thanks for the idea though.


If it is a carbon steel one I guess it has to do with steel fatigued by excessive steeling or overheating by sharpening on a dry grinding wheel which was very common in the old days. Have one that only took an edge after removing something like 10mm of width. If you aren't familiar with the feeling on the stones you will notice it can't be deburred. A carbon Sab should easily take a 25 or 30° _inclusive_ edge. Not advisable, but perfectly possible.


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## noj (Sep 14, 2022)

It's a carbon steel one. I got it brand new around 1980. It has never been sharpened on anything but a stone, or heated in anything but hot water from a faucet when rinsing it. The steel is very very soft. A 30 degree inclusive will go dull, and edge visibly missing spots after cutting one onion (just a random example). I wasn't rock-chopping, and I use either a soft wood board or Hasegawa FSR. I deburr with leading edge strokes are a slightly higher angle, and I have checked using cork and wood (not every time I sharpen of course) that I got rid of it. None of my other knives do this, so I doubt it's technique.

Just double checked, so a bit of a correction. My "angle guide" I use for it is 21 degrees, so that's 42 inclusive. The "guide" is just a home made piece of wood for reference. I don't have the muscle memory for angles like that, and the feedback from the metal is mostly nonexistent.


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## Benuser (Sep 14, 2022)

noj said:


> It's a carbon steel one. I got it brand new around 1980. It has never been sharpened on anything but a stone, or heated in anything but hot water from a faucet when rinsing it. The steel is very very soft. A 30 degree inclusive will go dull, and edge visibly missing spots after cutting one onion (just a random example). I wasn't rock-chopping, and I use either a soft wood board or Hasegawa FSR. I deburr with leading edge strokes are a slightly higher angle, and I have checked using cork and wood (not every time I sharpen of course) that I got rid of it. None of my other knives do this, so I doubt it's technique.
> 
> Just double checked, so a bit of a correction. My "angle guide" I use for it is 21 degrees, so that's 42 inclusive. The "guide" is just a home made piece of wood for reference. I don't have the muscle memory for angles like that, and the feedback from the metal is mostly nonexistent.


I know the modern ones are even softer than the vintages, but this is extreme. Which brand?


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## noj (Sep 14, 2022)

On the handle, almost worn away, it looks like four stars and an elephant, and below that "Sabatier". Anything marked on the blade is gone. I don't think this is one of those fake Sabatier's (my parents had one, unfortunately).

The thing is very hard to sharpen, or at least you have to use very good technique. One little wobble, and the whole edge goes missing.


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## Benuser (Sep 14, 2022)

The Elephant and the 4 stars are trade marks bought and used by Thiers-Issard, one of the few remaining firms. TI and K-Sabatier were in those years the best ones.
Something went very, very wrong with the Heat Treatment. Or it is simply a counterfeit.


Sabatier Kitchen Knives at The Best Things


Where did you buy it?


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## noj (Sep 14, 2022)

I don't recall details about purchase. I was working a summer job in a restaurant, and got one of what they had, and I liked using (or thought I did).


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## r0bz (Oct 10, 2022)

Benuser said:


> Quite sure the tip will end far too high. And the heel section is being neglected.


what is wrong with what he is doing in the vidoe ?
i want to learn from this


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## jwthaparc (Oct 10, 2022)

I spent some time just watching what the tip of the knife is doing. For that heavily curved chef knife blade profile. It looks fine.

It did look like at least going in on direction he could have definitely grinded the heel a bit more, but because of the technique he uses, it doesn't seem that he spent drastically less time on the heel than the rest of the blade.

I will add that I'm not recommending his technique, I'm just saying it looks fine for what it is. Btw he passed away last year from complications with covid.


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## r0bz (Oct 11, 2022)

noj said:


> Here is a thought experiment, and pictures. First, as perhaps an
> oversimplification, imagine your control of the knife is on just two
> axis: your wrist (rotation angle along the axis of your knife handle),
> and your wrist height. Of course, the human body is more complicated,
> ...


i was confused about this also 
i can just lift my elbow up and then the tip is touching the stone and ican sharpen it what got me confused is why do i need to lower the spine to the stone .....
do you know why does it happen geometrically ?


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## noj (Oct 11, 2022)

r0bz said:


> i was confused about this also
> i can just lift my elbow up and then the tip is touching the stone and ican sharpen it what got me confused is why do i need to lower the spine to the stone .....
> do you know why does it happen geometrically ?


I'll assume you don't want a lot of math as an answer. Take a close look at the second and third photos. What I did was assume that I am trying to achieve a constant angle in the curve, which I guarantee by using a beveled plate in contact with the board. As I moved from picture 2 to picture 3, I merely changed the point of contact further along the circle (or with a real knife, along the belly towards the tip). As you can see, the handle has to be raised while changing the wrist angle.

You can get the tip in contact with the stone is many ways, but they will not get the right bevel angle. You can simply lift the handle; you can simply reduce the angle; the only right (for constant angle) answer lies somewhere in between. Exactly where in between is the hard part, and it's nonlinear. Trial and error, I guess.

All that said, you may find it easier/better to use "smooth following of the curve to the tip" as mentioned earlier, and then blend the belly of the knife with the flat section. I like this method especially with touchups because I am either not scrubbing, or making enough passes scrubbing to follow the curve as smoothly. I used and old knife I don't mind experimenting on. Jon's magic marker trick can help. I can pretty much tell from the reflection off the bevel too. But this paragraph is more technique than an answer to your question.


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## r0bz (Oct 11, 2022)

noj said:


> 'll assume you don't want a lot of math as an answer


go for it


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## HumbleHomeCook (Oct 11, 2022)

My take on Jon's video is he is demo'ing laying back toward the spine on single or wide bevel knives. That's because he's trying to maintain the profile of the bevel up to the shinogi line.

In Peter's video he has a standard double bevel with just a narrow edge bevel. He doesn't have to roll that knife toward the spine because he isn't trying to raise a shinogi or alter the overall profile. He's simply sharpening the edge bevel so he can just lift and swipe.

You can't discount the knife types for each technique.

I could be wrong but that's what I see.


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## noj (Oct 11, 2022)

r0bz said:


> go for it


Look at my thought experiment. In picture 2, the wrist angle is wa = x > 0 (maybe 60 degrees with my plate) and the lift angle the handle above horizontal is la = 0. At the far extreme of a 90 degree belly is picture 4. The wrist angle is 0, and the lift angle of the handle above horizontal is la = x. In between (a more normal knife shape) involves both variables. I am feeling uninspired to come up with the model of a 5-axis milling machine. Sorry if that's not precise;-)


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## noj (Oct 11, 2022)

HumbleHomeCook said:


> My take on Jon's video is he is demo'ing laying back toward the spine on single or wide bevel knives. That's because he's trying to maintain the profile of the bevel up to the shinogi line.
> 
> In Peter's video he has a standard double bevel with just a narrow edge bevel. He doesn't have to roll that knife toward the spine because he isn't trying to raise a shinogi or alter the overall profile. He's simply sharpening the edge bevel so he can just lift and swipe.
> 
> ...


I actually spoke to Jon about this, and he is talking about the narrow edge bevel. He was even reading this thread;-) I stopped trying to figure out what Peter was saying, though not meant as a criticism.


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## r0bz (Oct 11, 2022)

noj said:


> Look at my thought experiment. In picture 2, the wrist angle is wa = x > 0 (maybe 60 degrees with my plate) and the lift angle the handle above horizontal is la = 0. At the far extreme of a 90 degree belly is picture 4. The wrist angle is 0, and the lift angle of the handle above horizontal is la = x. In between (a more normal knife shape) involves both variables. I am feeling uninspired to come up with the model of a 5-axis milling machine. Sorry if that's not precise;-)


interesting did not understand tho


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## MowgFace (Oct 11, 2022)

HumbleHomeCook said:


> My take on Jon's video is he is demo'ing laying back toward the spine on single or wide bevel knives. That's because he's trying to maintain the profile of the bevel up to the shinogi line.
> 
> In Peter's video he has a standard double bevel with just a narrow edge bevel. He doesn't have to roll that knife toward the spine because he isn't trying to raise a shinogi or alter the overall profile. He's simply sharpening the edge bevel so he can just lift and swipe.
> 
> ...



I use Jon's method on all of my knives. 

As the tip curves up, rotating the blade towards the spine reaches the area the same way as lifting your wrists. Take one of your knives to a stone without scrubbing and try to lay the bevel flat on the stone as you get to the tip.

Using a wide bevel knife just gives you a better visual than with a full convex knife. Technique is the same. Takes some getting used to, but even take out your folder and try to lay its bevel flat. When you get to the tip, your elbow moves closer to your hip, and the blade rotates toward the spine.


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## HumbleHomeCook (Oct 11, 2022)

MowgFace said:


> I use Jon's method on all of my knives.
> 
> As the tip curves up, rotating the blade towards the spine reaches the area the same way as lifting your wrists. Take one of your knives to a stone without scrubbing and try to lay the bevel flat on the stone as you get to the tip.
> 
> Using a wide bevel knife just gives you a better visual than with a full convex knife. Technique is the same. Takes some getting used to, but even take out your folder and try to lay its bevel flat. When you get to the tip, your elbow moves closer to your hip, and the blade rotates toward the spine.



Gonna have to try it!


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## MowgFace (Oct 11, 2022)

If you want to use a wide bevel as a visual learning experience, take it and press the wide bevel flat against your table/desk. Continue to keep the wide bevel flat against a surface and move up towards the tip.

As you get towards the sweep and especially right at the tip, you will notice the handle of your knife change orientation. This is what you need to replicate when tip sharpening.

*This is similar to the plate excersize*


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## noj (Oct 11, 2022)

r0bz said:


> interesting did not understand tho


My experiment, or the text? Picture 2 is on the flat or heel. Picture 4 is at the tip if it curved a full 90 degrees. An actual knife is probably a lot less than 90 degrees - somewhere in between. On the flat, the handle isn't lifted, and the wrist angle is whatever your bevel angle is. On the 90 degree tip, your wrist angle must be 0, and the handle angle is at whatever your bevel angle is. An actual knife is somewhere in between - specifically, the handle is elevated and the wrist angle is less than the bevel angle.


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## superworrier (Oct 11, 2022)

My takeaway is for this type of thing, it's better to just think less mechanically and just think about following the curve of the knife. If you try and calculate the right amount to turn/lift it's gonna be a mess. Luckily, your brain and body are pretty good at this type of thing if you just try and do it naturally/visualize it. I'm pretty sure anybody (without any knife experience) would be able to understand swiping the knife along the edge and maintaining a more or less consistent angle.


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## noj (Oct 11, 2022)

MowgFace said:


> If you want to use a wide bevel as a visual learning experience, take it and press the wide bevel flat against your table/desk. Continue to keep the wide bevel flat against a surface and move up towards the tip.
> 
> As you get towards the sweep and especially right at the tip, you will notice the handle of your knife change orientation. This is what you need to replicate when tip sharpening.
> 
> *This is similar to the plate excersize*


Interesting, I thought that was a related, but maybe (just haven't thought about it until now) slightly different phenomena. Wide/single bevel are usually ground such that the shinogi is a constant height. Even with no belly curvature, the distal taper means you cannot achieve that using a constant angle. There was a nice video of this, specifically for single bevels that I saw somewhere on the forum.


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## superworrier (Oct 11, 2022)

Also my understanding is that this is not actually sufficient: if you naturally do this you will make the tip bevel too wide/flatten out the tip profile because as the edge curves more, the pressure is more concentrated and you actually sort of deform the tip, which is why that sort of rocking technique exists. The other remedy I heard is to just use less pressure near the tip.


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## superworrier (Oct 11, 2022)

noj said:


> Interesting, I thought that was a related, but maybe (just haven't thought about it until now) slightly different phenomena. Wide/single bevel are usually ground such that the shinogi is a constant height. Even with no belly curvature, the distal taper means you cannot achieve that using a constant angle. There was a nice video of this, specifically for single bevels that I saw somewhere on the forum.


Yes. This was a good video. Does anybody have the link to the thread? I remember he said there was a part 2 coming


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## MowgFace (Oct 11, 2022)

noj said:


> Interesting, I thought that was a related, but maybe (just haven't thought about it until now) slightly different phenomena. Wide/single bevel are usually ground such that the shinogi is a constant height. Even with no belly curvature, the distal taper means you cannot achieve that using a constant angle. There was a nice video of this, specifically for single bevels that I saw somewhere on the forum.


I think that coming to terms that a "Constant angle" does not exist. Which is more or less why we do not buy in to sharpening systems.

"Keeping a steady angle" is a relative term.


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## noj (Oct 11, 2022)

MowgFace said:


> I think that coming to terms that a "Constant angle" does not exist. Which is more or less why we do not buy in to sharpening systems.
> 
> "Keeping a steady angle" is a relative term.


In the video, he meant putting the whole shinogi on a single plane is not possible if the blade has distal taper and constant shinogi height. That's what I meant by "constant angle", which might not have been the best term.


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## noj (Oct 11, 2022)

superworrier said:


> Also my understanding is that this is not actually sufficient: if you naturally do this you will make the tip bevel too wide/flatten out the tip profile because as the edge curves more, the pressure is more concentrated and you actually sort of deform the tip, which is why that sort of rocking technique exists. The other remedy I heard is to just use less pressure near the tip.


I find the rocking technique or "smooth following of the curve to the tip" my preference. It seems to get all the angles right almost naturally. Plus, looking at the bevel, or magic marker says so.


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## noj (Oct 11, 2022)

superworrier said:


> Yes. This was a good video. Does anybody have the link to the thread? I remember he said there was a part 2 coming



This thread! ;-)

www.kitchenknifeforums.com/threads/video-for-those-that-are-interested-in-sharpening-single-bevels.60538/#post-926394


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## jwthaparc (Oct 11, 2022)

r0bz said:


> i was confused about this also
> i can just lift my elbow up and then the tip is touching the stone and ican sharpen it what got me confused is why do i need to lower the spine to the stone .....
> do you know why does it happen geometrically ?


You don't need to. Some people are do sometimes change the angle going towards the tip to make the edge bevel a more acute angle. Though normally you really don't want to change the edge angle.


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## superworrier (Oct 11, 2022)

jwthaparc said:


> You don't need to. Some people are do sometimes change the angle going towards the tip to make the edge bevel a more acute angle. Though normally you really don't want to change the edge angle.


No, this is to keep the edge angle the same. However, I think you don't need to consciously do it, it will happen naturally. In fact, it is very natural to rotate the spine/handle. You would probably only not do it if you're trying very hard not to/too mechanical


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## superworrier (Oct 11, 2022)

noj said:


> I find the rocking technique or "smooth following of the curve to the tip" my preference. It seems to get all the angles right almost naturally. Plus, looking at the bevel, or magic marker says so.


Yes, it's super natural and intuitive. Overthinking is what causes people to be confused. Once you lift, you naturally rotate as well. The only thing I don't like about the rocking is I find it hard to do on the back side of the knife


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## noj (Oct 11, 2022)

noj said:


> My experiment, or the text? Picture 2 is on the flat or heel. Picture 4 is at the tip if it curved a full 90 degrees. An actual knife is probably a lot less than 90 degrees - somewhere in between. On the flat, the handle isn't lifted, and the wrist angle is whatever your bevel angle is. On the 90 degree tip, your wrist angle must be 0, and the handle angle is at whatever your bevel angle is. An actual knife is somewhere in between - specifically, the handle is elevated and the wrist angle is less than the bevel angle.


Hope this helped conceptually. As someone already said, overthinking (or detailed math) probably won't help with freehand sharpening. I mean, would you be any further along if I said this? ;-)


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## HumbleHomeCook (Oct 11, 2022)

Gosh damnit @JBroida! I don't know if I want to curse you or celebrate you. 

This whole thing distracted my thoughts all day. I just couldn't visualize it and trying to simulate it with my Spyderco Endela on my desk at work just wasn't doing it. I know that John knows what he's talking about so I knew the issue was with me and @MowgFace added to my need to know.

So like every boy with an exciting new curiosity, I rushed home, did my chores, and gave it a shot. After four plus decades of doing the tip lift, it felt awkward but I managed it and damnit if it doesn't work.

And once I did it, it just seemed to make perfect sense and like all my previous consternations, even just hours before, were silly. I'm still not sure my brain grasps the geometry yet but it surely does work.

I don't know if I'll adopt it full stop but I will damn sure keep trying it.

Never stop learning. Never stop exploring. Never stop discovering! This is why I love sharpening so much.


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## noj (Oct 13, 2022)

superworrier said:


> Yes, it's super natural and intuitive. Overthinking is what causes people to be confused. Once you lift, you naturally rotate as well. The only thing I don't like about the rocking is I find it hard to do on the back side of the knife


I just read this, notice the same, and after pondering for a bit, I think I know what can cause this. Keep in mind I tend to use my right hand to hold the handle regardless of sharpening on the left or right side of the knife. When using a sweeping motion on the right side, I have a strong tendency to move the handle to the side as I approach the tip. This creates a natural smooth lift and rotation - at least for me. On the left hand side, I have a strong tendency to move the handle more vertical as I approach the tip, and therein lies an issue. The lift is intuitive, but the rotation isn't - actually, it feels awkward. One method to combat this is to hold the knife handle with my left hand for the left tip. Just thought I'd share the observation.


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## superworrier (Oct 13, 2022)

noj said:


> I just read this, notice the same, and after pondering for a bit, I think I know what can cause this. Keep in mind I tend to use my right hand to hold the handle regardless of sharpening on the left or right side of the knife. When using a sweeping motion on the right side, I have a strong tendency to move the handle to the side as I approach the tip. This creates a natural smooth lift and rotation - at least for me. On the left hand side, I have a strong tendency to move the handle more vertical as I approach the tip, and therein lies an issue. The lift is intuitive, but the rotation isn't - actually, it feels awkward. One method to combat this is to hold the knife handle with my left hand for the left tip. Just thought I'd share the observation.


That is a good point. It definitely feels less intuitive on the other side. I do find switching hands to be surprisingly natural, just because sharpening the other way is just weird.


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## mpier (Oct 14, 2022)

On my off hand motion I tend to rotate my stone to a 45 degree angle, adjust my stance and approach it from the back side of the stone. In this way you can keep all the same motions and the tip feels more natural to sharpen. I’ve also been switching hands which seams to have good results it just feels so awkward at the tip.


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## Ethan (Dec 18, 2022)

For what it’s worth, I had brought in a knife into JKI for choil and spine rounding/polishing (also just wanted an excuse to visit the store and crew there).

In addition to the knife I brought which was purchased elsewhere, I brought my regularly used Ginga (purchased from him) for him to refinish and sharpen (I figured I might as well bring it and it ended up being a big learning opportunity so I could see what Jon does).

I’ve taken a picture of what the tip looks like because I have had the same issues with you regarding tip sharpening and found what you said about not being able to gain a lot of information from the sharpie at the tip very compelling and relatable.

Here are two images of the tip of my Ginga after Jon’s work. I didn’t realize that tips could look like that when sharpened correctly and had associated this with the beginning of a bird beak forming out of my own ignorance and lack of knowledge.

Apologies if the photos are bad quality, lmk if you want me to send more.

As an aside, when Jon first handed me the knife (this was the first time I had had a knife of mine sharpened by someone else). I was immediately blown away at how even the bevels were. I wasn’t surprised in the slightest but it hit different seeing it in person.

I don’t remember what the tip looked like when it was new but I’m fairly confident that it didn’t look like that. 

I think it fundamentally changed my preconceived notion of what the bevel at the tip of a knife should look like when sharpening.


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## jwthaparc (Dec 19, 2022)

Thats usually what a tip looks like when either the thickness behind the edge increases at the tip and the angle at the bevel stays the same . Or if someone changes their angle as they get to the tip (lowering the spine of the knife).

It could be either one if those.


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## EricEricEric (Dec 19, 2022)

Just the tip…


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## r0bz (Jan 1, 2023)

noj said:


> Here is a thought experiment, and pictures. First, as perhaps an
> oversimplification, imagine your control of the knife is on just two
> axis: your wrist (rotation angle along the axis of your knife handle),
> and your wrist height. Of course, the human body is more complicated,
> ...


it seems from your experiment that it shows the opposite, that you need to rotate toward the blade in order to raise the angle between the spine and the stone because as you lift up it decreases the angle between the knife and the stone....
please tell me why am I wrong


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## noj (Jan 1, 2023)

r0bz said:


> it seems from your experiment that it shows the opposite, that you need to rotate toward the blade in order to raise the angle between the spine and the stone because as you lift up it decreases the angle between the knife and the stone....
> please tell me why am I wrong


As with many things in physics and engineering, measurements are dependent upon the observer. In the case in question, it's a little complex because of all the degrees of freedom. Imagine observing (and measuring) the angle* looking straight down the center of the handle, angle* = 0 parallel to the stone, and increasing in the counterclockwise direction (for right handed users). With the handle about parallel with the stone, the angle* is about what the edge bevel angle is. At least with the plate experiment, and you get into the curve, the rotation occurs clockwise (for right handed users). This is rotation is toward the spine (as I would describe it), and decreases the angle* as my observer sees it.

I may not be understanding your argument precisely. Keep in mind that in my experiment, I was letting the constant bevel angle dictate what the answer is, rather than any intuition.


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