# What is going on with this edge?



## turbochef422 (Nov 23, 2014)

My new knife a konosuke white #1 k-tip gyuto came is and looked great. I've had like 6 or 7 konosuke knives before and really enjoy all of them. So I used it with the ootb edge and it was ok. No. Chipping good to go 




So I go to put my edge on it and a few swipes on a king 800 pretty light and there is metal all over the stone



I go about my sharpening debur and it all came off in like one piece almost and it's sharp as hell. Today I cut 2 apples. No seeds no core just sliced apples and the whole edge from one side to the other looks like this



It's just crumbling what's going on with this thing?


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## chinacats (Nov 23, 2014)

Crappy heat treat?

If you were new to sharpening I would think you just left a burr and it came off clean on the stone, but I think you would recognize that, so back to heat treat causing a weak edge? Sometimes you just have to get past the first sharpening, maybe it just takes two rounds on this one to get to fresh steel? If go back at it, second times the charm.


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## chefcomesback (Nov 23, 2014)

I have witnessed fragile out of the box edges in some knives , after a sharpening session from coarse to fine grit If they continue , then I may start questioning other factors


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## mark76 (Nov 23, 2014)

Yes, it could be the heat treat, although I regard Konsuke very high in that respect. It could also be that the original edge was not very good. If you then just touch up the edge, the new edge could be very fragile. What I'd do is completely remove the original edge by blunting the knife straight on your coarsest stone (metal removal) and then put a new edge on it. If the chipping then still happens: back to the shop/manufacturer.


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## Sabaki (Nov 23, 2014)

could be overheated steel during forging resulting in big grain size, hopefully it's only along the edge and a few sharpenig sessions takes care of it?

Or maybe it was thin as possible at the edge when you got it and when you went over that 800 grit stone it could'nt hold that edge anymore and broke off?

hard to say, as said, try some sharpening sessions if it takes care of it otherwize return it!


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## turbochef422 (Nov 23, 2014)

I'm gonna sharpen it again today


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## CoqaVin (Nov 23, 2014)

Ill take it off your hands? LOL nice Fuji I have a HD 270 Kiri


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## labor of love (Nov 23, 2014)

Sharpen it again and use it some more....theres a good chance this problem goes away.


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## EdipisReks (Nov 23, 2014)

Steel can get overheated during the final grind, that would be my guess.


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## zitangy (Nov 23, 2014)

I wld attempt it this way...

a) Just using the weight of a knife, at 90 degrees cut it into a fine honing rod say 10 times. This will force the weakened fine edge to curl easily .

b) Now to sharpen...only with cutting strokes into the stone.. edge leading strokes so as to break the curl after which you will have a rounded Apex adn work slowly to get a pointy Apex. . Spine leading strokes ( as in stropping) will only uncurl adn you don't know when the curl is gone as it will only uncurl and let yu have a fine edge but with weakened metal.

# At times, after creating the curl on a rod.. I wld break it on a rod .. by honing it with cutting strokes only and then refine it with alternatiing stokes ( lighter pressure to chase for the Apex and then proceed to get it stoned with normal touch up maintenance sharpening. 

# There are times that I do the "light cutting" on the 1000 grit stone too during the sharpening process.. But doing it on a rod is more intuitive for me .. easier and faster.

The edge of a New Knife stabilize after a couple of light sharpening after the weakened metal is removed. Being a New Knife,, not much metal removal is required...

Hv fun and good luck...D


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## zitangy (Nov 23, 2014)

I wld attempt it this way...

a) Just using the weight of a knife, at 90 degrees cut it into a fine honing rod say 10 times. This will force the weakened fine edge to curl easily .

b) Now to sharpen...only with cutting strokes into the stone.. edge leading strokes so as to break the curl after which you will have a rounded Apex adn work slowly to get a pointy Apex. . Spine leading strokes ( as in stropping) will only uncurl adn you don't know when the curl is gone as it will only uncurl and let yu have a fine edge but with weakened metal.

# At times, after creating the curl on a rod.. I wld break it on a rod .. by honing it with cutting strokes only and then refine it with alternatiing stokes ( lighter pressure to chase for the Apex and then proceed to get it stoned with normal touch up maintenance sharpening. 

# There are times that I do the "light cutting" on the 1000 grit stone too during the sharpening process.. But doing it on a rod is more intuitive for me .. easier and faster.

The edge of a New Knife stabilize after a couple of light sharpening after the weakened metal is removed. Being a New Knife,, not much metal removal is required...

Hv fun and good luck...D


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## Benuser (Nov 23, 2014)

I guess the weak factory edge is all about factory deburring with hasty buffering. Make sure to remove a bit of steel.


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## Chuckles (Nov 23, 2014)

> Steel can get overheated during the final grind, that would be my guess.



That's what I was thinking too.


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## chinacats (Nov 24, 2014)

Is this series hand sharpened (on stones) by the maker? Do other large producers do this? I realize this is a higher end Konosuke.


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## labor of love (Nov 25, 2014)

Any updates? How is the edge holding up after sharpening?


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## turbochef422 (Nov 25, 2014)

I sharpened it for a while taking off some steel every time I finished one side it looked like this




There are curls of steel all over the blade and stone. I finally got past it I think after 3 sharpening sessions. However after deburring with cork and hard felt the knife was sharp for maybe 1 to 1 1/2 onions. So I sharpened up my vintage sab that stayed sharp the whole shift+. I'll give it another go and see after thanksgiving I guess.


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## CoqaVin (Nov 25, 2014)

get a new one?


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## labor of love (Nov 25, 2014)

yeah...time to get in touch with the vendor unless someone has a better idea.


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## CoqaVin (Nov 25, 2014)

yea sounds like a good idea to me, maybe the HT didn't go right or something, im not sure


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## Geo87 (Nov 25, 2014)

You started with a coarse stone right? The weak factory edge should be gone after 3 sharpening sessions. 
I would be contacting the vendor


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## masibu (Nov 26, 2014)

Sounds pretty lame, I would expect a lot more from a knife like this. If I see this happen I usually think to myself I havent deburred properly or something but it seems like you know what you're doing. Outside of sending it back I would try raising a burr on a higher grit stone just to see what happens. In saying that it seems like you're going to have no knife left to sharpen at this rate if it just keeps crumbling


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## chefcomesback (Nov 26, 2014)

I hope the vendor is knowledgable and you don't get the : you have used/ sharpened the knife , can't take it back answer


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## turbochef422 (Nov 27, 2014)

Actually konosuke wanted the pics I took and said they'll take care of it one way or another. I guess he hoping to get some info from the pics so I don't have to send it back. I do know he wants to test the steel but we re not at that point yet. There definitely is no burr left it's coming off in one big piece with every stone. So I'm just loosing steel every time I flip the knife on every stone.


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## chinacats (Nov 27, 2014)

^^ Good on Konosuke! 

Cheers


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## CoqaVin (Nov 27, 2014)

turbochef422 said:


> Actually konosuke wanted the pics I took and said they'll take care of it one way or another. I guess he hoping to get some info from the pics so I don't have to send it back. I do know he wants to test the steel but we re not at that point yet. There definitely is no burr left it's coming off in one big piece with every stone. So I'm just loosing steel every time I flip the knife on every stone.



that's kind of crazy that the steel is just basically crumbling every time it hits the stones, probably a faulty heat treat


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## psfred (Nov 27, 2014)

It is possible to get a granular structure in steel by improper heat treat that results in a very hard but crumbly edge, which is what you have. Improperly tempering can do that too, I think, especially if it's not hot enough. 

And it's always possible the wrong steel got used to make the knife, so the heat treat was all wrong. I'd think that very unlikely, but strange things happen occasionally.

Peter


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