Question about angle for amateur home sharpener

[Danejah]

Ive been a very amateur/inspiring knife sharpener for many years, but due to my available time and number of knives I keep (when one dulls, I grab another) I am prevented from sharpening consistently. I believe consistency is what allows someone to get good at something. Ill go maybe a month or more before I get back to the stones and I feel like every time I need to in many ways recover the muscle memory and relearn many of the strategies. My primary education has been from JKI videos, a few Bernal cutlery videos and recently the Milan videos (when ive got the time).

For the sake of keeping this short, my question relates to angles when sharpening. I know angles in general is a topic most people don’t really try adhere to anything to rigid and it can differentiate from knife to knife but in a Bernal video I see it talked about placing 2 quarters on the stone to find your angle, Milan talking about roughly 15 degrees and in a JKI video Jon mentions how you can use your level on your phone if you really want to figure it out. To me 2 quarters seems like a really low angle(~5 degrees) when I use my phone to find 15 degrees. Enough of a difference to make me question and in a way loose confidence in what I’m doing. I am always able to form a bur and my knives end up reasonably sharp, but rarely as sharp as I feel I can really get them. I know there is more to it but from an intro standpoint, this feels like step one and I find myself questioning it. Curious to hear what folks opinion is on this and if there is a better thread(I'm sure this has been covered somewhere) please point me in that direction. Thanks!

 

[SwampDonkey]

I use my pinky as an angle guide under the spine to spot-check. When I compared to some angle guides it was roughly 12°. I always happen to have a pinky finger on me so it became my standard and now that all my knives are sharpened like that I can feel the edge/follow it on the stone without really checking. Certain stones really help you feel what's going on which can make a big difference before the muscle memory is locked in. That's why I'm such a Chosera fanboy.

I switch hands when sharpening so the blade edge is always facing away from me, so the method works. Not sure it's as useful if you flip direction but keep same hand.

 

[HumbleHomeCook]

Good questions.

Let's break it down a little bit. Sharpness isn't really about the edge angle. Cutting performance is influenced by it but pure sharpness at the edge not so much. Sharpness is about how fine the very apex of the edge is.

If you're getting a burr, you're apexing the edge. Now, you can do that at say 45 degrees but of course that won't make for a very nice cutting experience but if you're down around 15 and getting burrs, your challenges aren't in your angle. You may be damaging your apex during your progression or in stropping or not deburring well or something like that.

My advice is to pick a knife to experiment with. Doesn't mean risk messing up, but just having a dedicated knife to help eliminate variables and build your knowledge. Next, grab a higher grit stone if you have one. This isn't for sharpening, just for visuals. Use a marker to paint just the edge bevel (I like red). Then do a couple passes on your high grit stone and observe. The marker won't lie. Repeat a couple times and on both sides. This will give you an idea of what you feel is the right angle vs. what you're seeing on the knife and how consistent you are. Keep in mind, you're likely to see variation down the edge from past grinding but what you're looking for is if it stays consistent. You're testing you here, not the knife. This exercise is just knowledge gaining.

Then pick a stone, just one stone. If your knife is dull and needs to be worked up, pick a lower grit, something in the 400-1k range is good. Don't move up until you're gaining confidence on this stone. This may take multiple sessions. We need to be sharp on the lower grit, that sets our apex. After that, the goal is to not screw up the work you've done and to refine the edge. Pick a medium to test cut, I like receipt paper cuz it's readily available. Test the whole edge, look at the cut, listen to it, feel it. On a lower grit it will be a little rough but should still cut clean and you'll know the difference.

Don't force things. Take your time and be honest with yourself. If you get tired or flustered, stop and come back another time. It'll come.

 

[Danejah]

Thanks you guys, this is super helpful. I’ve got some practicing to do but it’s always nice to hear from other folks and get their opinions on what works. I like the marker exercise, I feel like building consistency is key.

 

[Delat]

You could try a set of these angle guides
https://www.amazon.com/gp/product/B01N4QMO7U/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&th=1
Like OP, I don't sharpen often enough to build muscle memory so I actually attach one of these to my knife while sharpening. It's nice for knowing exactly what my angle is, e.g. I recently decided to switch from 15dps to 12dps. It definitely slows you down vs true freehand though.
https://www.amazon.com/gp/product/B07ZWW3BW5/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&th=1

 

[1315]

Im in your situation too! A couple things. Google "15 degrees" and print the angle. Then, get hard plastic stock (old credit card, or fake one that comes in the mail) and transfer the 15 degree to the plastic. Easy way to gauge.
Secondly, once i find the angle, get a comfortable, then firm grip on the handle.
This makes the strokes more repeatable in the robotic motion until you get the feel. I found my grip was too light and the blade was not staying at a consistent angle, as evidenced by checking via the magic marker method on the edge (hint).

 

[Rangen]

In your position, I would put aside concerns about absolute angle, and just focus on improving your skills against an existing bevel. Get a beater knife, or a knife you are willing to abrade more than usual, and work with that. If it's carbon steel, all the better; the burrs don't hold on so persistently as with stainless. Do not use cheap stainless, Shun, or Global for this; it's asking for frustration, as those are extra-challenging to sharpen.

Your focus should be on sharpening the knife angle as it is, learning to feel where the edge is, and when you are sharpening right on the bevel. This can take a long time to build up to. By all means use a sharpie, repeatedly, to align your intuition with reality. Try raising and lowering the angle and move gently over the stone, to see how it feels when your angle is too high or too low.

Watch Jon's JKI sharpening videos and pay close attention to hand position. I don't sharpen exactly like that -- I have the edge facing me on both sides, which I prefer, and my hand position is a little different. I had to put my thumb right behind the bevel, to get my positioning locked in, but it was a wonderful starting point, and forced me to think about hand position. Getting your hand position right, for you, is a key skill. You want it to be very natural, almost automatic, for the knife to be on the bevel.

After that it's just practice, building the muscle memory and refining the best hand position and motions for your body geometry. You'll eventually be able to easily stay on the bevel even with knives that have very narrow bevels. Sharpening practice tends to be self-perpetuating, because as you get better, your standards for what sharp means will rise, which means you will be less able to tolerate anything less than a good edge on all your knives, and will likely want to sharpen more often.

 

[SwampDonkey]

Sharpening practice tends to be self-perpetuating, because as you get better, your standards for what sharp means will rise, which means you will be less able to tolerate anything less than a good edge on all your knives, and will likely want to sharpen more often.

Especially once you try naturals for the first time and get that caveman serotonin release from rubbing good metal on good rock. I genuinely look forward to using my coticules any time I'm sharpening.

 

[milangravier]

Hey,
I have just made a french language live on my instagram about those questions,
Here it is :
It is in french but you can ask Youtube to create an English subtitle (it's working ok actually).

About angles, don't be too focus about them, a kitchen knife is grinded very thin (3/6° maybe) and from experience users felt that 15° edge will allow this edge to hold it's shape without chipping or bending. This is a common experience but it is not talking about what knife, what steel was made the knife and some knife would need more than 15° to really hold their edges, and some knives will be able to hold their edges with less than 15°.
Other parameter : what will be the use of the knife ? Workhorse? Slicer on fresh fish ? Vegetables ? As I would advise to slightly adjust the angle of your edge depending the task you want the knife to do.
Other parameter : Putting a very even 10° edge on a knife is a bit harder to made than a even 15 or 20°, so I would sugest to start with a little more angle when you learn sharpening.
Then whatever the angle of the edge you finally decide to put on your knife, try to stick to it and try to be consistent. In the video, I talk about hand position but it is also important to check with a bright light your knife to check if you kept your angle or finally grinded two surfaces (two angles) instead of one.

 

[Benuser]

Hey,
I have just made a french language live on my instagram about those questions,
Here it is :

Ça fait plaisir, merci !

 

[daveb]

Someone smart told me early on: "A consistent angle is much more important than any absolute angle."

I'm just repeating it.

 

[Jovidah]

Or just wobble all over the place and say you were going for convex...

 

[Danejah]

Hey,
I have just made a french language live on my instagram about those questions,
Here it is :
It is in french but you can ask Youtube to create an English subtitle (it's working ok actually).

About angles, don't be too focus about them, a kitchen knife is grinded very thin (3/6° maybe) and from experience users felt that 15° edge will allow this edge to hold it's shape without chipping or bending. This is a common experience but it is not talking about what knife, what steel was made the knife and some knife would need more than 15° to really hold their edges, and some knives will be able to hold their edges with less than 15°.
Other parameter : what will be the use of the knife ? Workhorse? Slicer on fresh fish ? Vegetables ? As I would advise to slightly adjust the angle of your edge depending the task you want the knife to do.
Other parameter : Putting a very even 10° edge on a knife is a bit harder to made than a even 15 or 20°, so I would sugest to start with a little more angle when you learn sharpening.
Then whatever the angle of the edge you finally decide to put on your knife, try to stick to it and try to be consistent. In the video, I talk about hand position but it is also important to check with a bright light your knife to check if you kept your angle or finally grinded two surfaces (two angles) instead of one.

Thank you @milangravier, I appreciate the feed back and will watch the new video you posted. I really enjoy your videos there is so much interesting and useful information.

 

[Ruso]

The guides that measure the distance from the spine to the stone, like stack of coins, will not give you a consistent angle for each knife. It depends on how tall/wide the blade is (petty vs gyuto vs cleaver).
I like the approximation of half of 90 degree is 45 and then half of that distance is ~ 22 so a half of 22 is 11 so, sharpen around that angle.

 

[1315]

Right! I still like my angled plastic card for reference, as i found my perception of the angle was different when i actually had the blade on the stone, mainly from my grip overriding my eyes. Once i let the Plastic angle guide help determine my grip , it makes it easier to maintain an equal or lesser angle, and then visualize Ruso's tips.

Ive noted some pro videos on YouTube, where it appears their angles are different when they shift from right side to left side sharpening. Gotta be from visual perception and grip. (Based on height of spine above the stone surface).

For me, to establish angle: eyes and grip lie, but the plastic reference is constant and a good place to start.

 

[blokey]

Zero egde everything

 

[stringer]

Zero egde everything

I'm always riding that line as close as I can. Going back and forth between too thin and not thin enough. At least until I get to really know what a knife can handle. If I have a new knife with no damage after a few heavy chopping sessions. Then I know it can handle being a little thinner. And if it starts to accumulate damage too quick, then I temper it back with a micro bevel. You can go through some knife height until you get the hang of it. But then once you get a knife dialed in. You only really gotta do touch-ups.

 

[Nemo]

You can use trigonometry to give a decent approximation of your sharpening angle. Using the sine function, if you lay the knife flat on the stone then raise the spine by:

1) Half the height of the blade, you have a 30° angle
2) A third the height of the blade, you have an appropriately 20° angle
3) A quarter the height of the blade, you have an appropriately 15° angle
4) A fifth the height of the blade, you have an appropriately 12° angle
5) A sixth the height of the blade, you have an appropriately 10° angle

Having said that, as previously explained, the exact angle is not that important. I'd probably start closer to 15° for softer steels like Aus8 or for highly alloyed steels like SG2 and closer to 10° for harder simple steels.

 

[Nemo]

I should add that keeping your knife thin behind the edge is so much more important than the actual sharpening angle. If you thin to an almost (or actual) zero edge, it's super quick and easy to put any edge you want on your knife.

 

[daveb]

You can use trigonometry to give a decent approximation of your sharpening angle. Using the sine function,....

Can you do trig on a cell phone?

(Nemo - you're showing your age )

 

[Rangen]

Can you do trig on a cell phone?

Sure, if you have an iPhone. Open up the calculator app, turn the phone on its side, and you have a scientific calculator.

 

[Nemo]

Can you do trig on a cell phone?

(Nemo - you're showing your age )

Sure can.

Although I did it on my tablet

 

[M1k3]

Can you do trig on a cell phone?

(Nemo - you're showing your age )

 

[Jovidah]

I can only second what others said: thickness behind the edge is the main factor in performance. It's really not worth obsessing over the angles...
If your knife is a clunky wedger, there isn't really an angle that's going to save it. If it's properly thin behind the edge, it really doesn't matter a whole lot (for cutting performance) whether you go at 10, 15 or 20 degrees.

 

[Ruso]

I can only second what others said: thickness behind the edge is the main factor in performance. It's really not worth obsessing over the angles...
If your knife is a clunky wedger, there isn't really an angle that's going to save it. If it's properly thin behind the edge, it really doesn't matter a whole lot (for cutting performance) whether you go at 10, 15 or 20 degrees.

But but but HHT :’(

 

[cotedupy]

I should add that keeping your knife thin behind the edge is so much more important than the actual sharpening angle. If you thin to an almost (or actual) zero edge, it's super quick and easy to put any edge you want on your knife.

^That is all ye know on earth and all ye need to know.^

---

A knife that is thinner bte but with a higher sharpening angle will perform way, way better than the same knife will if it is thicker bte but with a lower sharpening angle. And as a special bonus - it will also have better edge retention.

(Applies to pretty much all decent double bevel kitchen knives, with the exception of cleavers n bone stuff.)

 

[deltaplex]

Right, the real magic happens when you start pushing how acute an edge bevel can this steel take and still hold up to boardwork.

 

[The Forest Ninja]

I made 2 knives with 4mm thick steel this Summer. At 1st, it took me a long time to learn how to use my
little belt sander and hand grind bevels afterwards. I started with a #220 Nawiwa pink stone to do major
work and made the mistake of going to higher grit stones before I could cut anything. I watched video
after video of sharpening and couldn't grasp the concept.

This was until I pulled out a Japanese Santoku I got on EBAY and compared the blades. My 2 knives that
I made were too thick near the edge and the Santoku sliced paper like a razor basically cause it was so
thin. So I went back to the #220 Nawiwa and laid my blade almost flat on the stone and ground until
the bevel crept basically 1/2 way up the blade. Finally it started cutting and I've progressed to other
much finer stones over time.

I looked at those angle guides, but didn't want to risk scratching the blades with them and
knew that only freehand practice will give me the freedom to do it without a crutch.

In the end, it's all about practice and putting the time into it.

Cheers