Knife edge won't last after sharpening

Shop Knives and stones on ebay
Find deals on amazon
Kitchen Knife Forums

Help Support Kitchen Knife Forums:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
One question the OP still didn’t answer is how fast the edge fails. Burrs/wire edges are often the problem of less experienced sharpeners, but is that what is going on here or not?

Since the OP only recently started sharpening as I recall, I’d be tempted to say they must all have failed (his edges) quite fast, but who knows how and how long the knives are actually used or abused?
 
Last edited:
In addition to the advice about edge trailing strokes, try running the knife through hard felt if you have it, if not a wine cork several times.
 
it could also be that the steel simply dont last any longer than what you are getting.

straight off the stone sharpness last for like 5 minutes usually. just so you know. then it reverts to like 70-80% of that. powder SS can hold that 70% forever. carbon not so much. it just gets worse and worse in a linear fashion.

no one can really answer this question. you simply have to find out for yourself to be honest. and adjust accordingly.
 
It would help to know if it fails instantly or not, another problem entirely that is easily remedied... but all this... it's just wind right now.
 
probably the OP will find out whats really going on by simply looking at the edge closely. yeah it might sound stupid but seriously if you simply look at the edge you will see why its not sharp anymore, how it dulled. and you will also see how well you have sharpened it. use a loupe, scope or magnifying glass if you have to. i dont have to, i'm at -10 diopter from the start so i can focus on **** 4-5cm in front of my eyes. when i was young i could read text at 2cm (and only 2cm) beyond 2cm it would all get unsharp and hazy the further you went. i guess i was made for close up precision work
 
Do you know how hard the blade is? Some blades are quite soft such as Rc 52 or Rc54. While they can be made very sharp, the soft steel doesn't hold the edge very well and soon loses it and need frequent sharpening. Some European knives can be quite soft by design so they are easy to touch up on a steel.
 
Depends on the angle he sharps his knife at, the steel hardness and very important what cutting board he uses. In Japan it is common to use a microbevel for edge retention, if the knife is very thin at the edge. Just check out some videos on how to put on a microbevel.
Also try to use end grain cutting boards or rubber( Hasegawa). Even if the steel is on the soft side, it should hold up ok with a microbevel and a good cutting board.
 
danemonji said:
Depends on the angle he sharps his knife at, the steel hardness and very important what cutting board he uses. In Japan it is common to use a microbevel for edge retention, if the knife is very thin at the edge. Just check out some videos on how to put on a microbevel.
Also try to use end grain cutting boards or rubber( Hasegawa). Even if the steel is on the soft side, it should hold up ok with a microbevel and a good cutting board.
Click to expand...
We need more information.
 
  • Like
Reactions: ian
inferno said:
it could also be that the steel simply dont last any longer than what you are getting.

straight off the stone sharpness last for like 5 minutes usually. just so you know. then it reverts to like 70-80% of that. powder SS can hold that 70% forever. carbon not so much. it just gets worse and worse in a linear fashion.

no one can really answer this question. you simply have to find out for yourself to be honest. and adjust accordingly.
Click to expand...
Sounds like my problem. Knife is super razor sharp right after a 2k stone and maybe a strop (mostly not) after a 3 uses, i already lose that feeling. maybe i'm just spoiled by the fresh off the stone sharpness.

Both of my main gyutos are AS, one from Anryu, one from Yoshihiro. So the steel should be quite long lasting. Maybe my next knife i should look into a powedered SS. What maker and steel would be best for that?
 
coffeelover191919 said:
Sounds like my problem. Knife is super razor sharp right after a 2k stone and maybe a strop (mostly not) after a 3 uses, i already lose that feeling. maybe i'm just spoiled by the fresh off the stone sharpness.

Both of my main gyutos are AS, one from Anryu, one from Yoshihiro. So the steel should be quite long lasting. Maybe my next knife i should look into a powedered SS. What maker and steel would be best for that?
Click to expand...

Do you do the light test to make sure there's light reflecting on the edge of the knife?
 
coffeelover191919 said:
Sounds like my problem. Knife is super razor sharp right after a 2k stone and maybe a strop (mostly not) after a 3 uses, i already lose that feeling. maybe i'm just spoiled by the fresh off the stone sharpness.

Both of my main gyutos are AS, one from Anryu, one from Yoshihiro. So the steel should be quite long lasting. Maybe my next knife i should look into a powedered SS. What maker and steel would be best for that?
Click to expand...

No trouble with AS my friend, powdered steel ain’t nothing so good to compare except edge retention, and if your AS edge doesn’t hold it is not a matter of retention.

How do you cut, and on what type of surface, just so we have a whole ballpark of your use?

Edit: you’re not the OP so let that go. And BTW when you wash your AS knives dry the very edge dragging through the towel’s hem. Microscopic drops of water still clinging on the very edge eats away the fresh edge in storage time.
 
Last edited:
TSF415 said:
Do you do the light test to make sure there's light reflecting on the edge of the knife?
Click to expand...
no, what's that?
ModRQC said:
No trouble with AS my friend, powdered steel ain’t nothing so good to compare except edge retention, and if your AS edge doesn’t hold it is not a matter of retention.

How do you cut, and on what type of surface, just so we have a whole ballpark of your use?

Edit: you’re not the OP so let that go. And BTW when you wash your AS knives dry the very edge dragging through the towel’s hem. Microscopic drops of water still clinging on the very edge eats away the fresh edge in storage time.
Click to expand...
Wait, I am op.

I slice and dice on a Hasegawa sold core cutting board from MTC Kitchen. Occasionally (10%) on an acacia wood cutting board from crate and barrel.

I dry my towels pretty good using an ikea towel and it never stays wet for more than 5 mins max 10.
 
Sorry mixing threads you’re the OP. :p

What cutting technique is your default?

And I really meant: dragging the whole length of the edge through the hem of the towel. Drying on surface - and yes not cutting your hand or the whole towel - doesn’t always dry the very edge exactly because you are wary not to. When both sides are dried thoughout, go to the hem on a corner and gently glide the whole edge as if cutting it. It will penetrate but won’t go through with very light pressure. The very edge will be dry.

And I think what @TSF415 meant is do you check the edge against a direct strong light to verify that there are NO light reflecting on it? Light reflecting means a burr remnant or a spot where the edge wasn’t correctly apexed.
 
ModRQC said:
Sorry mixing threads you’re the OP. :p

What cutting technique is your default?

And I really meant: dragging the whole length of the edge through the hem of the towel. Drying on surface - and yes not cutting your hand or the whole towel - doesn’t always dry the very edge exactly because you are wary not to. When both sides are dried thoughout, go to the hem on a corner and gently glide the whole edge as if cutting it. It will penetrate but won’t go through with very light pressure. The very edge will be dry.
Click to expand...
Correct me if i'm wrong, but after washing. run the edge of the knife 90 degrees against an edge of a towel to dry very lightly, as if i was trying to slice through it? Wouldn't this dull the edge of my knife?


ModRQC said:
And I think what @TSF415 meant is do you check the edge against a direct strong light to verify that there are NO light reflecting on it? Light reflecting means a burr remnant or a spot where the edge wasn’t correctly apexed.
Click to expand...
Will hold up the edge of the knife to some strong light next time to see what it looks like, but not quite sure what to look for.
 
coffeelover191919 said:
Correct me if i'm wrong, but after washing. run the edge of the knife 90 degrees against an edge of a towel to dry very lightly, as if i was trying to slice through it? Wouldn't this dull the edge of my knife?
Click to expand...

My usual way to make sure the knife is dry is to just wipe it on the side of a paper towel roll after drying it with a towel. If you're really worried about microscopic droplets on the edge, you can make sure you're hitting the edge when you do this, essentially stropping (edge trailing stroke) on the paper towel roll. I'm not convinced that microscopic droplets on the edge are a problem though, even with white steel knives, much less AS. I mean, they're going to evaporate like instantaneously.

coffeelover191919 said:
Will hold up the edge of the knife to some strong light next time to see what it looks like, but not quite sure what to look for.
Click to expand...

Just looks for inconsistencies. The edge should look uniform all the way up and down. If there are little spots when you hold it to the light, that's bad.
 
Last edited:
coffeelover191919 said:
Correct me if i'm wrong, but after washing. run the edge of the knife 90 degrees against an edge of a towel to dry very lightly, as if i was trying to slice through it? Wouldn't this dull the edge of my knife?



Will hold up the edge of the knife to some strong light next time to see what it looks like, but not quite sure what to look for.
Click to expand...

No it won't dull it. Ian's way with the paper towel roll is a nice alternative - but since you can't avoid a towel when drying, the hem does just fine of it. Granted, as per Ian, AS is far from being the most corrosive carbon steel, but I just wanted to verify that you still applied some basic care to the edge, especially if cutting a lot of acidic stuff.

As for the light I'll admit it doesn't come naturally the first couple of times. Look under direct light, directly at it. No light should reflect from the apex. You might think at first it's reflections coming from the bevel or something, but if the blade is held perpendicular to your face, spine down, under direct light, the only reflections that can happen are ill apex or burr remnant. Trust that it is what you see, and make it a part of every stone in any progression in the deburring process.

Of course, blade has to be clean and dry, with no specs of dust or towel/paper sharpie (they might look like an inconsistency and lead you astray). I made a habit to lightly blow at the edge to remove any dust or residual towel sharpie before looking.
 
Maybe i'm just chasing that unicorn, fresh off the stone sharpness. It feels amazing and i'm super happy with the way the edge feels after a 2k stone. Smooth slicing paper, passes tomato test, good enough for all foods.

After about 5 uses, i'd say the knife is still sharp by a laymen's standard, just doesn't have that off the stone feeling. Normal?
 
coffeelover191919 said:
no, what's that?

Wait, I am op.

I slice and dice on a Hasegawa sold core cutting board from MTC Kitchen. Occasionally (10%) on an acacia wood cutting board from crate and barrel.

I dry my towels pretty good using an ikea towel and it never stays wet for more than 5 mins max 10.
Click to expand...

Check out Peter Nowlan's @Sailor videos. He stresses the light test all the time. As I get better at sharpening this has really helped me.
 
When I first purchased my Konosuke HD2 from Tosho Knife Arts I asked Olivia about sharpening and Ivan was there at the time and when I mentioned just using the strop Ivan thought that was a great idea and wondered how long the edge would last that way. With light use of the knife I didn't take it to a 1K stone for a few years and never at a lower grit. I think people rush to their sharpening stones way too soon.
 
TSF415 said:
Check out Peter Nowlan's @Sailor videos. He stresses the light test all the time. As I get better at sharpening this has really helped me.
Click to expand...
I fisrst learned the light test when learning to sharpen saw chains. Works on knives as well. If you can see light reflect off the very edge, it means that it's not a clean edge at that point. Either not apexed, has a residual burr or has a chip.
 
You must log in or register to reply here.

Latest posts

Back
Top