Grind issue for the experts.

[danemonji]

Hello guys,

I have a Munetoshi butcher which has a grinding problem. Can any expert tell me how I can fix this for the long term? So far I've tried to grind it away as i kept sharpening and thinning the knife but it' not going away.
I am attaching a photo.

 

[RDalman]

It's difficult to tell on a pic just but that doesn't look like a grind issue really to me, just normal lightly hollow ground bevels from grinding on wheel. You rarely get fully flat finished bevels. Are you not able to get a even burr?

 

[M1k3]

Munetoshi is known for having some or a lot of concavity.

 

[danemonji]

Yes it is a hollow in the side of the grind. The bad part is that it almost hits the edge and it's really deep. I think it goes beyond the central axis of the edge. Can this be fixed or should i buy another one with a better grind?

 

[valgard]

Yes it is a hollow in the side of the grind. The bad part is that it almost hits the edge and it's really deep. I think it goes beyond the central axis of the edge. Can this be fixed or should i buy another one with a better grind?
View attachment 69207

[emoji51]

 

[HRC_64]

I think it goes beyond the central axis of the edge. Can this be fixed or should i buy another one with a better grind?...

If a defect goes thru the centre-line, the knife is "true overgined" and cannot realistically be repaired

Apologies to be the bearer of bad news, perhaps others can look at this and see if this isn't the case. Repair is always possible if you are OK with making a suji/petty or shorter knife.

 

[labor of love]

Return it.

 

[J.C]

Is that your first sharpening session?

my munetoshi slicer also came with some low spots issue. But it started to slowly fade away every time i put it on the stone.
This is the current state, notice the lows spots near the kanji area, it used to be the size of a pinky finger

 

[valgard]

Is that your first sharpening session?

my munetoshi slicer also came with some low spots issue. But it started to slowly fade away every time i put it on the stone.
This is the current state, notice the lows spots near the kanji area, it used to be the size of a pinky finger

What he has isn't a simple low spot, it's an overgrind, and as a result his profile will be fked as he sharpens that knife, at least for a while until he goes beyond that issue, which might take several mm. This is also more critical in a knife that will be used on the board.

 

[Robert Lavacca]

I would try and return it. I just recently picked one up and the heel of the blade was a little wonky. Almost like a tiny part of the edge on the heel is higher than the rest of the heel. Sure it will be fine after sharpening it but that looks like it could be a problem. Love that little thing though I would try and get a new one

 

[bahamaroot]

Looks like a major overgrind and it's already reaching the edge. Of course it is hard to tell just how deep it is from a picture.

 

[danemonji]

Thanks for the input. Looks like i need to buy another one. This time i will ask for one without a hollow grind

 

[zizirex]

That looks worse than TF over grind

 

[danemonji]

Well it's not an expensive knife and I beat the hell out of it.
I was just hoping I could take that blemish out by grind or some sort of bevel adjustment in time. But i guess I should just buy a better version to keep. No problem

 

[RDalman]

IF it goes past central axis then sure it is "overgrind", but it is still fixable over time as long as the edge steel is thick enough, as this is a fairly short bevel knife. If it sharpens well as is now, don't worry about it just start every sharpening on that spot, be mindful of profile alteration while raising a burr there first, and proceed from that. I don't think you would be able to get one without hollow grind if that's how they're made.

 

[TB_London]

It’s a butchery knife, just use it. If it develops the mildest recurve from that hollow it doesn’t really matter- go and look at some knives in a butchers - they’ll have all kinds of funky profiles from steeling.
It’s a fully functional knife. You won’t be getting a nice pretty kasumi polish until you’ve used and sharpened it for a few years, but hey ho, you’ll have a number of years of usage.
Functionally is it not working to butcher with?

With a gyuto that needs to make board contact an overground can lead to accordioning cuts. But not the case here. Use it, sharpen it, enjoy it.

If you want to spend money on another knife then get something different, a honesuki, a hankotsu, an atamatori, etc

 

[RobinW]

If it is so deep that it passes the center axis, how can the lamination line be almost straight through the concavity?

I would have assumed in that case it would make a pretty drastic curve upwards?

what am I missing?

 

[bruce8088]

return it like that dude with the tf and ask for the seller to cover shipping and dont bother with another one cause they are all like that.