How to sharpen uneven bevels

[jfindon]

I will be honest, I am scared to sharpen my Olamic 247 because it's my most expensive and favorite knife. Couple with the fact that the bevel seems uneven from factory as seen here:

How do I go about this to keep the bevel decent? Do I set the angle for the widest bevel, where the light is reflecting most in the picture, and have it set the new bevel toward the heel of the blade? The other side seems not to be as bad. My fear is that I'm going to have on side with a super high bevel and the other with a different bevel. How do you correct this?

 

[Sergeua]

I would start out with higher angles even more than the widest part and see how it goes. Like go more obtuse and work that heel in with the rest of the blade. Can always take away more metal later by going steeper.
Remember to post pictures after and wait a bit so people give you more pointers

 

[RadialBladeworks]

I would personally do a reprofile, but just go slow and switch sides often and constantly check your edge. Generally-speaking you only reprofile a blade once so take the time and set a nice one. But yeah, I don’t really think you should worry much about keeping the original profile

 

[Wowbagger]

As a rule you probably won't be able to recreate the look of the bevels from the factory . . . I find . . . because they sharpen the knives with methods other than our guided sharpeners and so on almost every knife I wind up making both bevels sharpen able on my Edge Pro (which usually means taking off some significant material often near the point and usually rebevelling one or both sides ) and cussing them the whole time.

For instance I just sharpened a knife and one side the edge bevel was quite minimal, like a quarter of a millimeter and on the other side to sharpen at the same angle the bevel was about a whole millimeter wide. and that was making it a bit wider so everything could be run on the guided sharpener and have the stone actually down on the edge making it sharp.

Probably the main grind of the blade was not centered on the spine or like that. To actually keep the bevels looking just as they are from the factory I would probably leave the knife clamped as we see it and hold the stone like a file, mark the edge with sharpy and take just light passes, just enough to touch up the edge but not get up too far on the bevel. This is kind of crazy to learn; personally I only do this with my Shapton Ultra Fine triangle rod and just form the very lightest bur and take it off and by how the edge looks I can see that I am running right on the edge. Usually I hold the knife in one hand and the rod in the other under a bright light. For more major metal removal I wouldn't want to do it this way and so would just give up the factory bevels and shape the knife to my liking.

What to do if you chip it is another story. At that point just sharpen out the chipped area and probably reprofile it so it all works with what ever method you like.

Maybe if you don't feel bloody minded enough to do this on your best knife yet you might want to send it out to be sharpened until you get more time sharpening all your other edge tools.

 

[Chris "Anagarika"]

Why do you want to sharpen it? To use?
If that’s the reason, no worrying abiut keeping a nice even look, if factory angle of the primary grind is not even, not centered, etc. in this case, I’d just try making the edge straight & centered against spine.

If the purpose is to make it sharp and enjoy the look, I’d suggest sending it to some experts here (Josh, Jason or Martin). They can discuss & execute what will likely be better grind & look. The way I see, the heel is way obtuse and if it’s my knife to use, it’s going to be extra wide at the heel, because I’d like to keep the same angle throughout.

 

[jfindon]

I don't really care about keeping the factory bevel, I just don't want it to be wider on one side than the other. I don't want a mixture of obtuse and acute bevels anywhere, and that seems to have happened before when I sharpened a very cheap knife with horrid bevels. I can take a picture of that later, but I used the same angle on both sides and one got a much different bevel than the other.

So far of the good knives I've sharpened I've had very good results and they are very sharp for my standards. I don't think they had such an uneven grind like this one though.

 

[Sergeua]

Reprofile it, but don't do it with low angles right of the bat. If one side is wider, you go with lower angle just on that side to even it out or send it back to Olamic if that is confirmed to be the problem.

 

[RadialBladeworks]

I don't really care about keeping the factory bevel, I just don't want it to be wider on one side than the other. I don't want a mixture of obtuse and acute bevels anywhere, and that seems to have happened before when I sharpened a very cheap knife with horrid bevels.

The quality of the grind should be considerably higher on your Olamic. I know exactly what you’re talking about: I bought a cheapo kitchen knife from Walmart because I like sharpening so I figured I didn’t really need to worry about the thing going dull fast, but when I set the bevel, it was ridiculously inconsistent. It literally had wobbles in it. At a consistent 15 degrees across the entire bevel, the actual bevel width varied from almost nothing all the way up to several millimeters. The same thing occurred with one of my Ganzo knives except the bevel slowly tapered from fat to very skinny toward the tip. It bothered the hell out of me before I realized it wasn’t me, but rather it was the way they ground the knife. Again, cheap factory procedure. Generally speaking my more expensive knives have had better grinds and therefore gave me no issues.

Tl;dr I suspect the quality grind that Olamic puts on their primary bevels will not result in wavering edge bevels

Edit: Another example of this is the grind on my Real Steel H-something. It’s a 3.75” hollow ground blade. They didn’t curve the blade when grinding it, they just pushed the grind through horizontally, so the resulting bevel when set to a consistent angle throughout is thicker on the flat portion and visibly thinner once it hits the belly sweep and then fattens back up as it reaches the point. There is nothing practical that I can do to even the bevel out visually. But this is a result of $50 knife production as opposed to $450 knife production.

 

[David Martin]

Yes, but having to pay another 400$ for a craftsman to have the ability to pull off a straight bevel is ridiculous. Also, kitchen knives will flex
when sharpening and introduce a wider bevel. Whereas his short thicker steel blade will not. He can hit the angle and make it look better.
Don't be afraid of doing it. Think about it, study it and raise up your level of work. This will help you develop a step higher competence. DM

 

[Roikyou]

I have a Chris Reeve with the same heel. I went ahead and sharpened it. It's kind of sharp at the heal but I kind of lost a little at the heal. I've sharpened it twice since I've had it, each time the heal has improved. I'm just running with it instead of taking a lot of material off to re-profile.

 

[maximus83]

Yes, but having to pay another 400$ for a craftsman to have the ability to pull off a straight bevel is ridiculous. Also, kitchen knives will flex
when sharpening and introduce a wider bevel. Whereas his short thicker steel blade will not. He can hit the angle and make it look better.
Don't be afraid of doing it. Think about it, study it and raise up your level of work. This will help you develop a step higher competence. DM

What David said. Don't be afraid to tackle the sharpening--including fixing uneven bevels--on even a really nice knife. If you were talking about working the primary grind I'd probably urge you to go to a pro sharpener. But to just rework the secondary grind and the edge bevels, you can learn to handle that.

Couple suggestions I'd add:

* If not an advanced freehand sharpener (as I am not ), keep doing what you did here. Before you go start grinding stuff, share a pic and ask the forum pros for input on sharpening strategy. If you start sharpening and run into something that doesn't make sense, don't just keep blindly grinding and hope it'll all work out. Stop, take a pic, and again back to the forum for input. I recently had a thread on how to tackle some super uneven bevels. Got good advice that really helped. I practiced on a similar knife and was able to get the bevels--not perfect, but VERY close and good enough for working knife.
* Before you start grinding your nice blade, find a cheapo one with a similar blade shape if you can, and practice on that to help you visualize what you'll do on your nice one. For me, doing it this way really saved a lot of headache. $5 to $10 invested in a cheap piece of crap knife (I've been able to find a lot of cheap folders at BladeHq or even at yard sales, local pawn shops, etc.) can help you learn sharpening and reduce the chances of horking your nice blade.

 

[jfindon]

Well, it's been all the time and I still haven't done anything with this knife. It's still sitting in my KME right now, but I want to try it tonight.

One thing I don't understand is how my inital worry happens? Meaning how one side of the blade will have a higher secondary bevel than the other, if I find one side works at say 18 degrees and flip it over and make sure the stone is at 18 degree again, how would it do anything then make the other side identical? I swear that's what I did on a cheaper knife and wound up with a much higher secondary bevel.


Basically, this is what I'm afraid of happening. I did this awhile ago and don't really remember how I guess, but what would cause this? Not checking the angle on each side with an angle cube and only relying on what the KME told me, then having it affect the second angle more because the primary angle was different on both sides?

 

[Aquaholicc]

Well, it's been all the time and I still haven't done anything with this knife. It's still sitting in my KME right now, but I want to try it tonight.

One thing I don't understand is how my inital worry happens? Meaning how one side of the blade will have a higher secondary bevel than the other, if I find one side works at say 18 degrees and flip it over and make sure the stone is at 18 degree again, how would it do anything then make the other side identical? I swear that's what I did on a cheaper knife and wound up with a much higher secondary bevel.


Basically, this is what I'm afraid of happening. I did this awhile ago and don't really remember how I guess, but what would cause this? Not checking the angle on each side with an angle cube and only relying on what the KME told me, then having it affect the second angle more because the primary angle was different on both sides?

On my Wicked Edge this is most commonly caused by not finding the “sweet spot” when clamping said knife into the sharpener. Step one is to make sure your removing a even amount of sharpie across the whole bevel.

If you make a pass and notice that there is sharpie left towards the edge of the bevel and not the “heel” of the bevel when looking at the top of the blade then you need to reposition the blade the sir further back/closer to you. With that being said I’ve NEVER used a KME system so I’m not sure if this is the solution for that system but I just thought I’d share my experiences/thoughts on the subject!

Here is a Rat I did not long ago, had to reprofile the whole bevel on both sides as you can imagine at this price point how quickly/inconsistently the edge is put on this knife.

 

[HeavyHanded]

Well, it's been all the time and I still haven't done anything with this knife. It's still sitting in my KME right now, but I want to try it tonight.

One thing I don't understand is how my inital worry happens? Meaning how one side of the blade will have a higher secondary bevel than the other, if I find one side works at say 18 degrees and flip it over and make sure the stone is at 18 degree again, how would it do anything then make the other side identical? I swear that's what I did on a cheaper knife and wound up with a much higher secondary bevel.


Basically, this is what I'm afraid of happening. I did this awhile ago and don't really remember how I guess, but what would cause this? Not checking the angle on each side with an angle cube and only relying on what the KME told me, then having it affect the second angle more because the primary angle was different on both sides?

The actual angles are probably correct but the apex isn't centered on the edge (verify with visual inspection). You can gradually fix this without wasting a bunch of the useful life of the blade steel by working your touch-ups/resharpenings mostly on the thinner bevel side and just removing the burr on the wider side. Eventually the apex will be pushed to the center and the bevels will be even.

 

[maximus83]

Dang that is the best concise answer I have read to this "what do I do with uneven bevels" question. If we had a Sharpening FAQ, this one should be in it, as the question comes up often.

The actual angles are probably correct but the apex isn't centered on the edge (verify with visual inspection). You can gradually fix this without wasting a bunch of the useful life of the blade steel by working your touch-ups/resharpenings mostly on the thinner bevel side and just removing the burr on the wider side. Eventually the apex will be pushed to the center and the bevels will be even.

 

[jfindon]

Hey it's me again. This time I am actually out here starting this knife. Looks like the obtuse part by the heel is damn near 26 degrees according to my angle cube. I'll probably post updates as I go.

 

[HeavyHanded]

Hey it's me again. This time I am actually out here starting this knife. Looks like the obtuse part by the heel is damn near 26 degrees according to my angle cube. I'll probably post updates as I go.

A word of caution - when working on lowering or fixing the grind at the heel you can start cutting a lot of metal from the plunge line. This is especially true when using a guided system.

 

[jfindon]

A word of caution - when working on lowering or fixing the grind at the heel you can start cutting a lot of metal from the plunge line. This is especially true when using a guided system.

I do usually notice a ton of "biting" in that area, assume it's because of the square stone edge really hitting that spot?

Anyway, I had some small successes with my knife. I didn't accomplish the main goal of getting it sharp (ha) but I didn't screw it up, I didn't damage it, and I fixed the small chip that was in it. I'll post a picture a little later, had some issues with the tip it looks like. Not rounded or anything, but you can see the scratch pattern is totally different or I didn't even touch it or something.

 

[kreisler]

just my quick 2 cents

The uneven bevel exfac is a natural testimony of most sharpening machines being rotary in some way, meaning that the principal grinding movement comes with a radius or curvature. This is correct because most of our medium sized knives have a convex shape with no recurves. Factories have big grinding wheels, big radius. When we use our clamp-based jigs, the grinding movement involves a radius too. When you sharpen a totally straight edge on the jig, you'll notice that the jig produces an uneven bevel. In turn, it means that the jig will only produce a 100.0% even bevel, if the knife edge follows the circular movement exactly. Etc etc (...)

To cut the story short, your jig will imprint its inherent bevel evenness on your blade, no matter what. If you're able to align the blade shape with the circular rod movement, then the bevel will look pretty even. The longer the rod, the bigger the radius, the more even the bevel will turn out along the entire length of the knife edge. Jig with short rods are, for that reason, not really suitable for sharpening long straight blades. While it is still possible (One could partition the blade into sections), it is a pita. Having said that, it is actually quite challenging to sharpen a long straight blade with any budget method (freehand or jig) because there is always some circular movement involved (body, arms, wrists, rods, ..).

One you've set the bevel with your jig, you should not use a different brand jig in future for resharpening the knife. Each jig model imprints its own inherent bevel geometry due to the length of the rod radius. The bevels produced by different jig models don't coincide 100.0%, not even 90.0%.

Kinda difficult to explain in words. Never mind. Good luck.

 

[Chris "Anagarika"]

just my quick 2 cents

The uneven bevel exfac is a natural testimony of most sharpening machines being rotary in some way, meaning that the principal grinding movement comes with a radius or curvature. This is correct because most of our medium sized knives have a convex shape with no recurves. Factories have big grinding wheels, big radius. When we use our clamp-based jigs, the grinding movement involves a radius too. When you sharpen a totally straight edge on the jig, you'll notice that the jig produces an uneven bevel. In turn, it means that the jig will only produce a 100.0% even bevel, if the knife edge follows the circular movement exactly. Etc etc (...)

To cut the story short, your jig will imprint its inherent bevel evenness on your blade, no matter what. If you're able to align the blade shape with the circular rod movement, then the bevel will look pretty even. The longer the rod, the bigger the radius, the more even the bevel will turn out along the entire length of the knife edge. Jig with short rods are, for that reason, not really suitable for sharpening long straight blades. While it is still possible (One could partition the blade into sections), it is a pita. Having said that, it is actually quite challenging to sharpen a long straight blade with any budget method (freehand or jig) because there is always some circular movement involved (body, arms, wrists, rods, ..).

One you've set the bevel with your jig, you should not use a different brand jig in future for resharpening the knife. Each jig model imprints its own inherent bevel geometry due to the length of the rod radius. The bevels produced by different jig models don't coincide 100.0%, not even 90.0%.

Kinda difficult to explain in words. Never mind. Good luck.

I think what you’re trying to say is similar to this old thread: https://www.bladeforums.com/threads/geometry-and-kinematics-of-guided-rod-sharpeners.1131476/