Knife feels duller after sharpening on higher grit stone

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I have Shapton Pro 320, 2000 and 5000. The first time I used the 5000, I sharpened a western stainless beater 320 -> 2000 -> 5000. The knife felted duller after a pass on the 5000 than when it came off the 2000 stone, which I thought is weird. I used the exact same technique, same angle and I deburr on each stone before moving on to the next. I chalked that up to the steel being soft, and couldn't hold a refined edge.

Today I tried it again, this time with my SG2 Makoto Sakura, 61HRC, still 320-> 2000 ->5000. Same thing. Off the 320 stone, reasonably sharp, cuts paper no problems. Cuts paper towel but not very well. Off the 2000 stone, cut paper really well, cuts paper towel better then 320, great. Then off the 5000 stone, still cuts paper, but struggles to make that initial cut into the paper, once it "catches" tho, cuts really well. Struggles to cut paper towel.

What am I doing wrong? Am I somehow rounding the edge on the 5000? or is it due to the more refined edge has less tooth and won't bite into paper/paper towel as easily?
 
On higher grit stones it is extremely easy to round over your apex because material removal is slow. In my experience, it takes a lot of practice before you can get a better edge off of 5k than you can 2k. I would try just doing deburring strokes on the 5k, to begin with, see if that doesn't do the trick. Good luck!
 
Troopah_Knives said:
On higher grit stones it is extremely easy to round over your apex because material removal is slow. In my experience, it takes a lot of practice before you can get a better edge off of 5k than you can 2k. I would try just doing deburring strokes on the 5k, to begin with, see if that doesn't do the trick. Good luck!
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Start here.
 
NotAddictedYet said:
I have Shapton Pro 320, 2000 and 5000. The first time I used the 5000, I sharpened a western stainless beater 320 -> 2000 -> 5000. The knife felted duller after a pass on the 5000 than when it came off the 2000 stone, which I thought is weird. I used the exact same technique, same angle and I deburr on each stone before moving on to the next. I chalked that up to the steel being soft, and couldn't hold a refined edge.
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I would avoid using the exact same technique with your fine stones as with your coarse stones. Each stone after the coarsest stone that you will use in your sharpening progression should be used only to polish the edge bevel with very light pressure. It's possible that what you are describing is the removal of microscopic "teeth" with overenthusiastic polishing on your fine stone.

It's also possible that you are either rounding the edge or raising a new burr on your 5k. Could you describe your deburring technique?

FWIW, IME, the ability to hold a polish is more related to grain (and possibly carbide) structure than hardness per se. Having said that, there is certainly no point going above 1k for Western Stainless.
 
The more I sharpen, the more I disagree with the idea of oversharpening. Rounding and deburring are much more often the culprits when your edge lacks initial bite. A 5k stone should leave bite, especially a shapton, they’re pretty aggressive.

I do think you can overpolish with a strop. You can definitely remove your teeth with a strop.

You’re also looking at two knives that bring their own special sharpening challenge. Soft western stainless is hard to get a really keen edge on. An SG2 knife can be hard to deburr, which would lead to the Makoto feeling sharp but choking on paper towel. Try to refine and deburr longer than you feel you should, first on the 2k then on the 5k. Try to remove the burr completely at each stone. You might get some great performance out of it. Leave the beater at 1-2k.
 
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Troopah_Knives said:
I would try just doing deburring strokes on the 5k, to begin with, see if that doesn't do the trick. Good luck!
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Thanks, will stick to deburring strokes on 5k for now.

Nemo said:
I would avoid using the exact same technique with your fine stones as with your coarse stones. Each stone after the coarsest stone that you will use in your sharpening progression should be used only to polish the edge bevel with very light pressure. It's possible that what you are describing is the removal of microscopic "teeth" with overenthusiastic polishing on your fine stone.

It's also possible that you are either rounding the edge or raising a new burr on your 5k. Could you describe your deburring technique?
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How do you do this "polish the edge bevel with light pressure"? Just sharpen and deburr at the same angle but with less pressure?

My current technique is sharpen while applying firm pressure on the edge trailing stroke. Raise a burr on both sides, then deburr on the same stone before moving on to the next. My deburring technique is from this kippington video. Two almost vertical stroke across stone with feather light to nil pressure, then alternate light edge leading strokes until I don't feel a burr anymore.
 
For me what I do as I go up to the higher grits, beyond 5000 even, I make sure I’m even lighter sometimes as light as a feather depending on how high the grit is and I also keep increasing the angle slightly. With incredibly hard steel it’s more difficult to take the burr off so you actually have to sharpen the burr off very gently and lightly.

This will also be dependent upon the geometry as well. For me it always seemed like it was so much easier to make a knife sharper the more convex the bevel. The flatter the bevel it seemed it was a lot more difficult to get sharp and keep, that may have to do with the fact that it was easier to squash the fine edge

You have to remember as you get the edge finer and finer it becomes thinner and thinner and actually leaves it in a state where it’s easier for it to break and then you can end up with the edge that’s flat. It’s kind of hard to understand because it’s on such a microscopic level it doesn’t seem like it would make such a difference but it does

I can’t tell you how many times I sharpened my ZDP – 189 knife, that I started out with, all the way up to 12,000 grit yet it couldn’t cut anything ver well and it made no sense to me at the time.

What changed things around for me, I can’t remember the name of the company, they sharpen all of their knives on natural stones and he explained it’s easy to break off the end and squash it when it’s so fine and the steel is so hard

That also pairs up with the idea that you need to make sure you’re using proper cutting technique, not pressing so hard into the board when you’re cutting, and also using a board that’s made with the end grain up. These concepts will increase the lifespan of the edge of the knife for the same reasons that we were talking about with the sharpening as the edge is so fine it’s not so strong.

That’s why you’ll see a lot of people that won’t sharpen to a very high grit on their knives, they usually stop between 1k-3k

My Mazaki was incredibly hard steel, but the bevel was so convex that it gave the edge a lot of strength. That knife was always consistently the sharpest knife in my arsenal and it always stayed the sharpest the longest


NotAddictedYet said:
Whats the adjustment necessary for high carbon steels? I assume "high carbon" means white and blue
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There is a fundamental problem. If you start on the first stone, the edge is blunt, damaged, the bevels don't meet. You may apply some pressure to remove a bit of steel. At the end, with the bevels meeting, the edge should be scary sharp. But very thin as well. Think a tenth of that of tin foil. From there on, you should considerably reduce your pressure, for deburring on the first stone, and for anything you're going to do with the next stone. Otherwise you will simply crush the new edge.
By the way, I wouldn't go on with the next stone if there was a lot of work done with the first one and heavy pressure being applied. Better look again at it next day, and repeat very lightly edge leading stropping and deburring on the first stone. With minimal pressure, as the edge is already there. For the next stones, a few light strokes are all you need to refine the scratch pattern created by the previous stone. A new burr, or the remnant of the previous one, will appear almost instantly, as the bevels already meet. Abrade the burr with a very light touch. You want to have as little contact with the edge as possible. You go to the finer stone if the burr only flips without getting smaller anymore. That small burr you can't get rid of is the only reason to go to the finer stone.
Three-quarters of your time will be spent on your first stone. With the next ones, the finer you get, the lesser there's to do. A few edge leading strokes, and above all, deburring.
 
NotAddictedYet said:
How do you do this "polish the edge bevel with light pressure"? Just sharpen and deburr at the same angle but with less pressure?

My current technique is sharpen while applying firm pressure on the edge trailing stroke. Raise a burr on both sides, then deburr on the same stone before moving on to the next. My deburring technique is from this kippington video. Two almost vertical stroke across stone with feather light to nil pressure, then alternate light edge leading strokes until I don't feel a burr anymore.
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Have a look at Pete Nowlan's (@Sailor) Knifeplanet.net sharpening series. One of the videos (?the second one) is on pressure levels during sharpening. Essentially, very light pressure is where you use only the weight of the knife (no downward pressure) while sharpening, so the edge leading and edge trailing strokes have the same amount of (very light) pressure.

If you are using the KDM, I don't know how this would work using it between each stone. When @Kippington was kind enough to walk me through it, he recommended that it was only necessary at the end of a sharpening progression. I guess if you used it at the end of each stone, you would have to exactly match the angle of the micro-bevel that you created with the previous stone. Failure to do this could round your edge and could possibly account for your knife being duller off a fine stone.

as @Benuser mentioned, the alternative to the KDM is to gradually reduce the burr with lighter and lighter pressure on your coarsest stone. Then use some type of deburring technique (I typically use feather-light edge leading strokes followed by a longitudinal stroke along the edge, often with a gentle drag through cork or felt). Then only very light pressure on any subsequent stones.

FWIW, I will often use the KDM for stainless steels (as a microbevel works well with them) and the more traditional approach for carbon steels.
 
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I started with a trio very much like yours - SP1K instead of SP2K.

SP5K is difficult to master. I killed a few good edges just like you along the way. I basically hated going to it. One of the thing that helped me was raising a bit of slurry (makes it feel creamier) and indeed use a very light touch. Another was to use it to fully sharpen a dull edge. Makes you spend much more time with it - which is really key to it all.

Lots of good advice given above so I'll just say to keep at it.
 
And/or your cheap beater is thick behind the edge? I would venture to guess it would perform better all together on your paper towel test with some thinning. Putting aside the "paper towel test" how does it perform on food coming off each different stone? I know this is not as fun to answer but...
 
I think everyone has hit the points pretty good hear the only other thing I would mention, if it hasn’t already is minimize your time on the higher grits stones. It really shouldn’t take more than a couple of light passes to accomplish what you are looking for, and as mentioned don’t hesitate in changing your approach, I think most of us use many different approaches for our knives, steels, grinding and polishing.
 
ModRQC said:
I started with a trio very much like yours - SP1K instead of SP2K.

SP5K is difficult to master. I killed a few good edges just like you along the way. I basically hated going to it. One of the thing that helped me was raising a bit of slurry (makes it feel creamier) and indeed use a very light touch. Another was to use it to fully sharpen a dull edge. Makes you spend much more time with it - which is really key to it all.

Lots of good advice given above so I'll just say to keep at it.
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"Makes you spend much more time with it - which is really key to it all."

Yep, there is nothing like practice. Just using a slower fine stone is a great way to build muscle memory. But there is very little instant gratification in it and lots of set backs for a beginner, it's the hard road and I think most would just quit in frustration.

I keep an eye out for old hunting knifes on the cheap. I will put them on a soft ark, just for practice, stone time.
 
So far I like all the responses I have been sharpening knives personally commercially for over 35 years. It is all about the fundamentals. That's not to say I have all the answers I don't. Discipline discipline discipline. There are many really good sources about knife sharpening. I would recommend referencing The Pasted Strop. Great info all theory applies to what ever you are sharpening. Just some of the terms Apex, Shoulder Bevel. convex bevel, Rollback, Keen edge, Foiling, convexity, Progression, Micro tearing, Micro Burnishing, I Guess I have said this before you might reference many sources. And then you will apply you interpretation to function. Some might disagree and it has been said, 99% of your sharpening will be done on the 1000 grit stones or plates. They are the workhorses. Once you get beyond the 1000 2000 3000 grit You are now going beyond micro tearing to basically burnishing the edge. You are increasing the possibility of foiling rollback convexing, even if you are seasoned sharpener. Thanks for the opportunity to add to the collective. There is a lot of good advice here. Sometimes the answers is much more complex than the question
.
 
Finger pressure has to be much lighter when sharpening on higher grit whetstone, can’t apply same pressure as coarse whetstone or medium. You can destroy the edge very easily if pressure & angle control is wrong.
 
NotAddictedYet said:
I have Shapton Pro 320, 2000 and 5000. The first time I used the 5000, I sharpened a western stainless beater 320 -> 2000 -> 5000. The knife felted duller after a pass on the 5000 than when it came off the 2000 stone, which I thought is weird. I used the exact same technique, same angle and I deburr on each stone before moving on to the next. I chalked that up to the steel being soft, and couldn't hold a refined edge.

Today I tried it again, this time with my SG2 Makoto Sakura, 61HRC, still 320-> 2000 ->5000. Same thing. Off the 320 stone, reasonably sharp, cuts paper no problems. Cuts paper towel but not very well. Off the 2000 stone, cut paper really well, cuts paper towel better then 320, great. Then off the 5000 stone, still cuts paper, but struggles to make that initial cut into the paper, once it "catches" tho, cuts really well. Struggles to cut paper towel.

What am I doing wrong? Am I somehow rounding the edge on the 5000? or is it due to the more refined edge has less tooth and won't bite into paper/paper towel as easily?
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Sometimes “over sharpening” can create a wire edge.

You might want to try stropping when you are finished with your sharpening regimen.
 
Very grateful to everyone sharing their insight and knowledge. It's great to have an idea of where to go next to sharpen;) my skills. I am still trying to process all the information and trying things out, reply might seem slow but I'm definitely here and learning.

Yesterday I tried doing some stropping on the 5000 stone with very light pressure as many has suggested. I am seeing an immediate improvement in how the knife performs in paper test. It's now almost on par with the 2000 grit edge with the paper test, though it still under performs in the paper towel test, and won't cut tissue. Still, the stropping took like 20 secs and worked liked charm, very pleased about that. Thanks KKF!
 
HumbleHomeCook said:
And just to toss it out there, there is absolutely nothing wrong with a 2k edge for the kitchen.
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Yeah there is... I have like 6 stones over that grit range that wouldn't get used wouldn't I pray for fairytales to exist. :p

But yeah absolutely. I mean you can get more of a silent killer going above, or suiting one steel best behavior, but somewhere 2K-3K is where most of the magic happens on good steels in the kitchen. Often you just don't see it because going like 1K-4K or even a wider, similar step up.

Edit: SP2K - Ouka are really good stones showcasing that range. Possibly why since I have both, it's a segment of stones I really lack further experience with. I don't think NP3K counts there. Mostly "2500" grits is the point - SP2K being slightly finer than it should, and Ouka coarser than it should, has made me devise 2.5K being that real sweet spot that might not get you refinements you're after, but otherwise always make for long lasting excellent kitchen edges.
 
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captaincaed said:
Congratulations! That’s great! Is your edge holding up well after board contact? After you draw the knife edge across the board a couple times will it cut paper towel cleanly?
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Thanks! The edge is holding up after multiple dinner prep sessions, so far so good. It does cut paper towel, but not so well, I wonder if I need to go back to 2000 and try again.
 
NotAddictedYet said:
Thanks! The edge is holding up after multiple dinner prep sessions, so far so good. It does cut paper towel, but not so well, I wonder if I need to go back to 2000 and try again.
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It's great to hear that you're making such good progress!

For me, that paper towel test is really just a post-sharpening check. It will loose the ability to do that cleanly after a few dinners, but should still perform on food for quite a while longer. The test for me is really to ensure the burr is well and truly gone at first, making sure the edge has the potential for a longer service life between sharpenings.

The long-term test for me is "cutting food" after making a few dinners. If you're struggling with cherry tomatoes... that's that task that always bites me in the ass. But a well set-up edge should freshen up quite a few times on a ceramic rod / coarse Arkansas if you put the initial work into really deburring well. Honest to god, for a relatively simple steel (iron and chromium carbides, none of the fancy vanadium crap), one swipe per side on a ceramic/Arkansas/Washita gets me back into cutting tomatoes for the rest of dinner.

I just reread that, and it sounds a little intense, but mostly I'm just excited you're making progress 😅
 
tostadas said:
I had similar experience with the 5k. @branwell experimented with removing the outer "layer" of the 5k stone and talked about it in a recent thread
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Just tried this tonight. Used my atoma to work up quite a bit of mud and did a quick a touch up. Very much liked the edge afterwards. Cut through paper effortlessly and cut paper towel fine and worked through dinner prep beautiful. Think I'm approaching OOTB sharpness if not exceeding it a little bit already. Very happy that the 5k edge is finally legit sharper than the 2k :)

Surface of the 5k stone still feels very fine but has a tiny bit more "grit" after removing the top layer. Now I really need try this on the 320 and 2k.
 
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