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angle consistency

Sun Dec 02, 2012 10:30 am

Hi all. First of all, great forum: I've been poking around for a couple week and feel like I've absorbed a lot of info. Paying more careful attention to burr formation/removal, as you guys emphasize, has really improved my results in the last couple sharp (I originally learned from Carter's videos, so all I'd ever really done is draw the edge through wood randomly throughout sharpening).

So my question (one of many I'll be posting in the next few days). I've been sharpening for a couple years now and get decent results off some 1000/6000 combo I got from Korin (and lately I've been starting with an extra course DMT to set bevels more easily on some knives). I started out using stacks of quarters to find angles. But unlike just about everybody else, I never stopped: every time I set the knife on the stone, I grab my stack of quarters lift the knife up to that height, lock my wrist, move the quarters, and start sharpening. I literally do that every time I switch sides of the knife; as you can imagine, that makes final stropping very annoying and so I was probably never doing enough of that in the finishing stages (and I never really experimented with stropping on leather for the same reason). I need to get out of this habit.

In my three most recent sharpening sessions (on a Carter funayaki, a Shun paring knive, and a Carter neck knife), I left the quarters alone. Instead, I'd lift the knife to what I reckoned was the right angle and gently push the edge forward gradually steepening until it started to bite into the stone, then I'd back off a hair and sharpen. Did that every time I switched sides. This is easier and faster than quarters. Got very clean bevels (for me), and the trick worked well on my razor strop which took all my edges to a level of sharpness I've never experienced before (and I didn't destroy the strop in the process!).

Still, this feels a bit like another crutch like the quarters (albeit more speedy/conveninent) and it won't work so well when I want to change bevel angles, rather than working with what I already have established (like when my friends bring me their blunt Cuisinart and Ikea knives). Is there some other way to get good at setting the knife on the stone at the same angle every time? Once I've got my wrist locked at an angle and start sharpening, I can maintain it, it's just I feel a bit lost when trying to find the angle to set my wrist at. Does my question make sense? Any suggestions?

Re: angle consistency

Sun Dec 02, 2012 11:47 am

I use pieces of cork cut with different angles, from 4 to 20 degree. I've them next to the stone to verify the inclination. To know to which sharpening angle that corresponds you should take into account the thickness of the spine.

Re: angle consistency

Sun Dec 02, 2012 8:46 pm

Welcome to 'the' forum!

It's a very good question.

So if you use quarters, remember that that is the angle measured at the spine, so a wider knife like a cleaver will be at a more acute angle than a narrow knife like a slicer or sujihiki. The quarters stack is further away from the edge.

Now when you use the technique of seeing where the edge digs in this works well BUT it inherently means that each time you do it, you are going to get a point of 'grab' that is less and less acute, giving you a more convex edge and an ever less acute angle with subsequent sharpenings.

The cure is to actually measure the angles. So you can lay the stone flat on the counter on a stone holder and measure the angle of the knife by putting the angle measuring cube on the blade. Be consistent here as Ben implies because the knife itself is not a flat surface but curved.

Another approach is to angle the stone to the desired angle measuring this angle with the angle cube. Then sharpen with the knife horizontal. This will give you a very high degree of angular consistency. Why? Because holding a knife horizontal is easier to do because of muscle memory than trying to remember say 14.5 degrees and the stroke is simpler too - just keep the knife in a horizontal plane and rotate it as you approach the tip so that the point of contact is perpendicular to the stone. Yea that's a mouthful.

Here's a video that helps explain this. I'm using a belt grinder but you do it the same way on a stone tilting the stone like I tilt the platen in the video.


Re: angle consistency

Sun Dec 02, 2012 9:32 pm

ken123 said:
"Another approach is to angle the stone to the desired angle measuring this angle with the angle cube. Then sharpen with the knife horizontal."

Something I never would have thought of that sounds like another great approach. I love the information you can find here!

Re: angle consistency

Mon Dec 03, 2012 5:48 am

I'm going to assume you don't have an angle cube yet nor do you have a vice that you can set the stone in and set it to a desired angle.

Don't sweat the angle too much, it sounds like you are alreadly good at maintaining an angle once you have it and that is quite important.

So your friends drop off their Cusinart's and IKEA and other such knives to do. You know by now that these can be sharpened from 19-21 degrees. You're free handing and the beauty of that is that you can adjust a little from the start to match the angle on each knife. Use the sharpie trick on that cusinart, and raise or lower the spine until you are hitting the spot, the mark is gone and you go from there. Creating the burr on both sides of the blade along the entire length of the blade means that you've hit hit the edge and basically removed the dull parts (after removing the burr). So whether you did this at 19.5 deg or 22 deg is not as important as forming and removing the burr on that first stone. The knife is sharp and now you can refine the edge with your 6k stone. You're friends are going to be startled by the edge, the Angle Police won't come looking for you. Not suggesting here that the angle consistency is not important, all I am saying is that it isn't critical to start with a "measured" angle, removing the sharpie means you're on target, just keep going at that angle.

The next knife may be a little different, could be a 10 inch no name chef knife (i.e. brand name worn off), so you may need to raise the spine a little more, the sharpie again will guide you and then be consistent. You have that down pat from what it sounds like.

Re: angle consistency

Mon Dec 03, 2012 9:15 pm

Thanks for the replies! I like the cork idea, sounds more convenient than quarters -- might make up a few to have as references for when I'm resetting bevels.

That video was very neat, Ken. Very helpful way to think about sharpening the belly of a knife. And thanks for the warning about convexing my edges -- that makes perfect sense, but it never would have occurred to me. I'll probably get an angle cube soon enough, but I don't want to fiddle with it every time I flip sides.

I guess what I'll start doing is let the edge bite into the stone when I'm remembering angles at the beginning of a session (or grab a cork!) and then just try to keep hitting that angle for the rest of the session, judging that I'm doing it well enough if I'm raising burrs. I've begun to strop my knives on leather every couple of days to maintain their edges, so hopefully that bit of extra practice will help my hands to start remembering the angles.

I do get my knives sharp -- shaving well and push-cutting paper at 1k -- it's just that my bevels aren't as crisp and even as some of you maniacs get! Practice, practice...

Re: angle consistency

Tue Dec 04, 2012 9:20 am

One of the most enjoyable parts of the experience was learning what body mechanics worked best for me, from the typical thumbs on the spine of the blade with edge leading strokes (per Mark's videos on CKTG) to the edge facing towards the individual with edge trailing strokes (per Murray Carter method), using the dominant hand only, then learning to be ambidextrous. Through experimenting with different styles I was able to adopt my own method which has been very rewarding. Since then, I have noticed EVERYTHING improve, including angle consistency without having to use coins, angle cube, etc. So learning which style was most comfortable and ergonomic for myself has upped my game more than anything else, plus it adds some uniqueness and artisan flair to your edges, something you created and not a device or machine. - Josh

Re: angle consistency

Wed Dec 05, 2012 5:35 am

That is great point Josh and it is exactly what happened to me. I've spent hours learning from the videos by Ken or Jason and then hours trying to duplicate techniques. This is a while ago now and while I was getting very sharp knives, the bevels were not perfectly the same on both sides of the knife. So I was unable to do with my left hand what I could with my right, too stoopid I suppose, the knife was sharp but that isn't good enough. Fine for my own knives but not for some others.
The turning point for me was a chance encounter with a very nice Japanese sharpener and then a fantastic series of videos that I found, I changed my technique a little, and it all clicked, the problem disappeared.
I often think of how cool it would be to have a sharpening session in person with the learned ones that teach us so much here on this forum.

Re: angle consistency

Wed Dec 05, 2012 8:14 am

Sailor wrote:... a fantastic series of videos that I found, ...

Just curious, what were the videos that helped you? Thanks :)

Re: angle consistency

Wed Dec 05, 2012 9:30 am

Edges with an artisanal flair! That sounds so cool I want to hit the stones right now and work on a new technique I've been trying and finding effective: continuous sweeps along the blade instead of my usual back and forth in sections. Too bad I tweaked my finger training for rock climbing last night and need to let it rest.

Yes, a sharpening session with the folks on here would be so valuable. The internet is neat in that it makes available what might otherwise be a very obscure bit of human knowledge; the downside is that it's very difficult to learn complicated motor skills without a "coach" in person to help.
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