Uneven Bevels on Left Side of Blade

[cazhpfan]

Hi KKF!

I'm right-handed and am having persistent problems sharpening the "left" side of blades (when viewed with the tip of the knife pointed away from the observer).

Here's an imgur album showing the issue: http://imgur.com/a/VHE1f

The first image shows the bevels on the "right" side of the blade (they're nice and even). The remaining three images show the problem (left) side.

I assume that I'm probably wobbling on the stones. I also suspect that "swinging" the blade from being perpendicular to the stone (when sharpening the heel) to a more natural 45* angle when sharpening the belly/tip is contributing to the problem.

Any and all suggestions for combating this issue are very appreciated.

Happy Holidays to you all!!!

Stones in my collection:

Bester 700 and 1,200
Cheap Suehiro combo stone (1000/6000). I only use the 6,000 side on this stone.

 

[ThEoRy]

Looks like possible overgrinds on the blade face. Maybe it's not entirely your fault. Who's the maker?

 

[cazhpfan]

Thank you for your response, Rick.

The maker is Takeda and the knife is a 210mm gyuto (that's not ground very well, actually).

But something is telling me that this is a technique issue on my side...

Maybe I need to flatten the blade road before I get an even finish?

Perhaps a different way of holding the blade during sharpening? Starting at the tip (instead of the heel) and working my backwards?

 

[clsm1955]

I had a similar experience. I recently acquired a razor sized Nakayama suita and was using it, with a progression of three naguras, to finish a couple of knives. They both ended up with a wavy bevel on one side. I don't know whether my problem was due to technique (probably the main factor, since it was on one side of these symmetrical knives), the smaller size of the stone, or the hardness of the stone. I went back and reworked them on a progression of more forgiving synthetics and got a good result.
I don't know if this helps other than to suggest trying a different sharpening set up.
Good luck!

 

[cheflivengood]

lighten your pressure and really focus on putting pressure only on the edge trailing stroke. also getting a perfect kasumi with synthetics in the high grit level is hard, maybe invest in a natral aoto or some soft finisher. Also finger stones are really easy and fun to learn to use.

 

[cazhpfan]

@clsm1955 I suspect this is something technique related. While my synthetic setup isn't ideally suited for kasumi finishes, I do get decent results on the side of the blade matching my dominant hand (see image below).

Are there any specific techniques that you use for sharpening the side of the blade that's opposite of your dominant hand?

@cheflivengood Do you use less pressure all throughout the entire sharpening session or just for those last strokes geared towards finessing the finish?

Good Side:

"Bad" Side:

 

[cheflivengood]

yes anytime i'm going for even finish the pressure is really light, using as much mug as posible

 

[The Edge]

Do you sharpen in sections, or do you work the entire bevel in each stroke? Uneven pressure is likely to be the cause in either case.

 

[cazhpfan]

Do you use this approach only your finishing stone or on all stones in your progression?

yes anytime i'm going for even finish the pressure is really light, using as much mug as posible

 

[cazhpfan]

I sharpen almost exactly as Jon demonstrates in this video. The right side of the blade is definitely easier to sharpen in one fluid motion...

[video=youtube;I-POg4dG784]https://www.youtube.com/watch?v=I-POg4dG784[/video]

Do you sharpen in sections, or do you work the entire bevel in each stroke? Uneven pressure is likely to be the cause in either case.

 

[The Edge]

I think you kind of stated what your problem is: "The right side of the blade is definitely easier to sharpen in one fluid motion..."

Since the left side is probably a bit more choppy and not fluid, the pressure isn't even distributed, and you are getting some low and high spots along the blade road. I would do as cheflivengood says, and try to lighten the pressure. Worry more about getting a fluid stroke on that side than getting things done quickly. If you get a bit tired, don't be afraid to take a break, so that you can have all your concentration at hand when you are sharpening. It's going to take some practice to get it right, but if you go slow, and worry about the details, speed will come with time, and you'll be able to add some pressure when you're starting out to speed up the process.

Hope that helps, and I love Jon's videos. He knows his stuff!

 

[cazhpfan]

Thank you for all the suggestions! I'll keep plugging away at it.

I agree with you regarding Jon's videos. His videos, and those created by Rick Theory (https://www.youtube.com/user/PCCkitchen), as well as Dave Martell (youtube.com/watch?v=MezIEKGk9T0), have been immensely helpful in learning how to sharpen.

I think you kind of stated what your problem is: "The right side of the blade is definitely easier to sharpen in one fluid motion..."

Since the left side is probably a bit more choppy and not fluid, the pressure isn't even distributed, and you are getting some low and high spots along the blade road. I would do as cheflivengood says, and try to lighten the pressure. Worry more about getting a fluid stroke on that side than getting things done quickly. If you get a bit tired, don't be afraid to take a break, so that you can have all your concentration at hand when you are sharpening. It's going to take some practice to get it right, but if you go slow, and worry about the details, speed will come with time, and you'll be able to add some pressure when you're starting out to speed up the process.

Hope that helps, and I love Jon's videos. He knows his stuff!

 

[The Edge]

I was thinking more about this last night, and figured out how to explain why I think it is uneven pressure. Most people think of wobble only from spine to edge, but you can also get wobble from tip to heel. When you have wobble from tip to heel, you are still keeping the angle correctly, but you start only using the edge of the stone to sharpen. I was thinking, looking at the pictures, that it looked like you were getting more pressure on the edge of the stone, not all the time, but maybe as you were moving to a new couple inches to sharpen. This would eat a bit more in to one part of the bevel a bit more than the rest of the blade road (even for just a couple strokes) before you steady out, and start to sharpen smoothly again. This creates a semi wavy pattern and uneven bevel, which to me seems like you have to some degree. Hope that gives a bit more insight in to what the problem could be, and I have no doubt with all the great videos you've been watching, that you'll get there in no time at all. Good luck!

 

[NotThinEnough]

uneven pressure and misaligned scratch patterns. be careful how you sharpen the left side of takedas as you need to match the direction of the original scratch patterns.

 

[Yamabushi]

Have you considered ambidextrous sharpening? I change hands in order to keep the blade always toward me and spine away. The symmetry of the method is what works so well for me. It may be worth giving a try?

 

[Matus]

I talked to Jon about this issue (I have the same problem and nearly all my knives can prove that). The reason is - I am always holding knife (handle) with my right hand and thus sharpening the left side is harder - it is much easier to slip what result in uneven bevel and finish. Jon told me - that even with this skill and experience he needs to be more careful with the left side and if he is doing some critical work (like sharpening left handed single bevel knives) that he will switch hands for the best result.

You have 2 options - get a lot more careful when sharpening the left side, or switch hands. I prefer the first one as that allows me to keep my right hand relatively clean and so I do not need to use any special precautions to keep the handle clean (stone mud tends to stick to some softer woods)

 

[cazhpfan]

Yes, I have considered ambidextrous sharpening many times in the past. The only thing holding me back is (a) the muscle memory of two years sharpening with one hand and (b) concern over staining handles with swarf/stone mud.

Did you start sharpening with a single hand and then transition to an ambidextrous style?

Are there any videos of people sharpening ambidextrously on youtube, etc?

Have you considered ambidextrous sharpening? I change hands in order to keep the blade always toward me and spine away. The symmetry of the method is
what works so well for me. It may be worth giving a try?

 

[cazhpfan]

It's reassuring to hear that I'm not the only one. It's sometimes a bit disappointing to see folks posting pictures of perfectly finished bevels on the forum and then comparing their results with those that one is getting.

By getting more careful with the left side, what adjustments do you find yourself doing? Do you slow down? Do you place special emphasis on smoothness of the strokes or sharpening angle?

I talked to Jon about this issue (I have the same problem and nearly all my knives can prove that). The reason is - I am always holding knife (handle) with my right hand and thus sharpening the left side is harder - it is much easier to slip what result in uneven bevel and finish. Jon told me - that even with this skill and experience he needs to be more careful with the left side and if he is doing some critical work (like sharpening left handed single bevel knives) that he will switch hands for the best result.

You have 2 options - get a lot more careful when sharpening the left side, or switch hands. I prefer the first one as that allows me to keep my right hand relatively clean and so I do not need to use any special precautions to keep the handle clean (stone mud tends to stick to some softer woods)

 

[cazhpfan]

You're correct. I make a conscious effort to use the entire surface area of the stone to minimize the amount of flattening I need to do (and thus how much stone I end up wasting).

And, yes, your replies do give me great insight; thank you for the help!

I was thinking more about this last night, and figured out how to explain why I think it is uneven pressure. Most people think of wobble only from spine to edge, but you can also get wobble from tip to heel. When you have wobble from tip to heel, you are still keeping the angle correctly, but you start only using the edge of the stone to sharpen. I was thinking, looking at the pictures, that it looked like you were getting more pressure on the edge of the stone, not all the time, but maybe as you were moving to a new couple inches to sharpen. This would eat a bit more in to one part of the bevel a bit more than the rest of the blade road (even for just a couple strokes) before you steady out, and start to sharpen smoothly again. This creates a semi wavy pattern and uneven bevel, which to me seems like you have to some degree. Hope that gives a bit more insight in to what the problem could be, and I have no doubt with all the great videos you've been watching, that you'll get there in no time at all. Good luck!

 

[Matus]

It's reassuring to hear that I'm not the only one. It's sometimes a bit disappointing to see folks posting pictures of perfectly finished bevels on the forum and then comparing their results with those that one is getting.

By getting more careful with the left side, what adjustments do you find yourself doing? Do you slow down? Do you place special emphasis on smoothness of the strokes or sharpening angle?

Yeah, there are more of us like that

Yes, I get slower and try to keep my left thumb on the spine on the blade to try to avoid slipping and scratching the blade. It does help with keeping the blade un/less scratched, but the edge bevel still shows some unevenness. What I found that having the stone in slightly inclined position (downwards away from me) helps in keeping the sharpening angle during the stroke.

 

[Yamabushi]

Yes, I have considered ambidextrous sharpening many times in the past. The only thing holding me back is (a) the muscle memory of two years sharpening with one hand and (b) concern over staining handles with swarf/stone mud.

Did you start sharpening with a single hand and then transition to an ambidextrous style?

Are there any videos of people sharpening ambidextrously on youtube, etc?

I've never looked specifically for any videos, but it is simply a matter of mirroring what you normally do when you sharpen the right side of the blade with the blade facing you. I initial started the "normal" way, but didn't like the lack of control and lack of symmetry I had when sharpening the left side of the blade. While I understand your "muscle memory/not wanting to start over comment", keep in mind you wouldn't really be starting from zero again. You have developed knowledge and a tactile sense that will be largely transferable when you switch to the left hand. Why not give it a try for couple of sharpenings and see if it makes sense to you?

 

[cazhpfan]

I will most definitely give it a try the next time I sharpen.

To be frank, the only thing holding me back from sharpening ambidextrously was the perception that it isn't the "Japanese way." After all, it's hard to deny that the Japanese masters have (at least until very recently) held a significant lead in all things knife making/knife sharpening.

I guess I need to give up preconceived notions and try different things...

I've never looked specifically for any videos, but it is simply a matter of mirroring what you normally do when you sharpen the right side of the blade with the blade facing you. I initial started the "normal" way, but didn't like the lack of control and lack of symmetry I had when sharpening the left side of the blade. While I understand your "muscle memory/not wanting to start over comment", keep in mind you wouldn't really be starting from zero again. You have developed knowledge and a tactile sense that will be largely transferable when you switch to the left hand. Why not give it a try for couple of sharpenings and see if it makes sense to you?

 

[cazhpfan]

I have attempted ambidextrous sharpening and can't get the hang of it; therefore, I'm back to sharpening with one hand.

The following adjustments have helped me achieve a slightly improved finish:

1) keep the knife at a 45* angle to the stone for the greatest length of blade as possible (the ferule will eventually get in the way and necessitate a 90* approach near the heel).

2) paying very close attention to the curvature of the blade. My Takeda does not have a particularly flat profile and sharpening requires constant adjustment to make sure that each portion of the edge hits the stone.

3) stones with good feedback help somewhat (though nothing will ever replace technique).

4) applying even finger pressure over the edge surface area in contact with the stone. I apply pressure via three fingers directly behind the edge and do my best to prevent tilt in either direction.

5) long, smooth strokes that are slightly slower than when sharpening the right side.

6) the right amount of pressure: not too much and not too little. There exists an inverted U-shaped curve between pressure applied and bevel consistency. Too little and the knife wobbles/slips. Too much and one get's cosmetic "divots" along the blade road.

I hope this helps those struggling with the same issue!

Images below...

 

[chinacats]

You can spin the stone to work on a corner...ferrule off the stone and you can maintain the 45 degrees and help to evenly use your stone at the same time

 

[cazhpfan]

I had never thought of that...

Thank you for sharing!

You can spin the stone to work on a corner...ferrule off the stone and you can maintain the 45 degrees and help to evenly use your stone at the same time

 

[The Edge]

That's looking much better! Glad you were able to make some adjustments to your sharpening routine, and see improvements. I'm a bit different than most people when sharpening, and my stone sits at a 45 degree angle to me when I sharpen. It aids me in not having the ferule get in the way when I'm sharpening the left side, and also makes things easier when sharpening the right, since the stone is lined up with my left hand (left hand is the one adding pressure, and just feels more natural to me).

 

[cazhpfan]

Thank you!

I've been thinking about the angleing of the stone:

Assuming that one sharpens with the right hand, the stone should be rotated 45* counter-clockwise, right?

Or is it just the opposite with a 45* clockwise rotation?

That's looking much better! Glad you were able to make some adjustments to your sharpening routine, and see improvements. I'm a bit different than most people when sharpening, and my stone sits at a 45 degree angle to me when I sharpen. It aids me in not having the ferule get in the way when I'm sharpening the left side, and also makes things easier when sharpening the right, since the stone is lined up with my left hand (left hand is the one adding pressure, and just feels more natural to me).

 

[The Edge]

Thank you!

I've been thinking about the angleing of the stone:

Assuming that one sharpens with the right hand, the stone should be rotated 45* counter-clockwise, right?

Or is it just the opposite with a 45* clockwise rotation?

I rotate the stone 45 degrees clockwise (and sharpen with my right hand), but in my opinion you should use whatever works best for you. We all have our own movements that feel comfortable to us.

 

[YG420]

That's looking much better! Glad you were able to make some adjustments to your sharpening routine, and see improvements. I'm a bit different than most people when sharpening, and my stone sits at a 45 degree angle to me when I sharpen. It aids me in not having the ferule get in the way when I'm sharpening the left side, and also makes things easier when sharpening the right, since the stone is lined up with my left hand (left hand is the one adding pressure, and just feels more natural to me).

same!

 

[cazhpfan]

I will give it a try and post back with some photographs.

Thank you for all the suggestions!

I rotate the stone 45 degrees clockwise (and sharpen with my right hand), but in my opinion you should use whatever works best for you. We all have our own movements that feel comfortable to us.