Rockstead Knowledge Thread

Twindog

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Do not sharpen it with a Sharpmaker! They are made to sharpen knives with a flat ground secondary bevel. Even attempting to put a micro-bevel on a zero-ground convex blade is trickier than it sounds. Rockstead recommends a specific stropping regimen on their website. Stropping is the way to go for someone who is not an expert as sharpening.

I take your point, but stropping out a chip will take a while, and if you use a coarse grit sandpaper to speed things up, you'll have a scratchy line along the edge shoulder. For sure, a Sharpmaker will change the convex edge to a V edge, but that's not a bad thing -- just different. The Rockstead recommended way to sharpen is to freehand strop on a soft backing. Because it's freehand, everyone will put a different convex edge on the blade.

Some years ago, Chris Reeve said he worked 6 months to develop a convex edge for a Sebenza. His recommended way to keep it sharp: the Sharpmaker.
 

CPP

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Some years ago, Chris Reeve said he worked 6 months to develop a convex edge for a Sebenza. His recommended way to keep it sharp: the Sharpmaker.
I was thinking that was the basis for the Sharpmaker recommendation. However, CRKs have hollow ground primary bevels and only the secondary bevel is convex, that's far from a zero ground convex blade. Even using the Sharpmaker to put a micro-bevel on a Rockstead would not be easy if even possible as the angle required to sharpen the edge of convex grind is beyond the 40˚ offered on the Sharpmaker.
 

Twindog

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I was thinking that was the basis for the Sharpmaker recommendation. However, CRKs have hollow ground primary bevels and only the secondary bevel is convex, that's far from a zero ground convex blade. Even using the Sharpmaker to put a micro-bevel on a Rockstead would not be easy if even possible as the angle required to sharpen the edge of convex grind is beyond the 40˚ offered on the Sharpmaker.

I just checked my Shin. The steepest angle on the laser protractor reads 18 degrees on one side and 16 degrees on the other. So a 40 degree inclusive micro-bevel would work. The steeper angles that you are talking about would be right at the apex, which doesn't read on my protractor because it's blocked by the edge higher up.

But it's the apex that needs to be removed.

If you want to maintain the zero ground convex blade, not just the edge, you'd have to regrind the whole blade.

Rockstead's advice is to send it back for resharpening or more serious blade work. The owner is restricted to maintaining sharpness as long as possible by stropping. But when resharpening is needed, they want you to send it back. For someone who's not super experienced at complex sharpening work, the choice to remove the chip is to send the knife back to Rockstead, regrind just the convex edge or convert to a V edge.
 

Berengir

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Does anyone know what it will cost to restore the knife by rockstead?

Shipping will cost me about € 90 to Japan and back. If that happens often, it light just not be the right knife for me. Maybe I should consider selling it, as I have not registered it yet.
 
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Oh dear. As the knife is so new, perhaps Rockstead would give you a free repair if the Zukuri fellow explained the story? I'm sure Rockstead and Zukuri would prefer not to lose a customer, especially one who actually uses his knife.
 

Berengir

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Oh dear. As the knife is so new, perhaps Rockstead would give you a free repair if the Zukuri fellow explained the story? I'm sure Rockstead and Zukuri would prefer not to lose a customer, especially one who actually uses his knife.
Not according to Zukuri. That does not fall under warranty.

And this might sound stupid, but even if it did, and the knife is returned to me as new... I'm not sure I'll dare use it again. It chipped cutting cardboard... not battoning or chopping wood.
 

Twindog

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Not according to Zukuri. That does not fall under warranty.

And this might sound stupid, but even if it did, and the knife is returned to me as new... I'm not sure I'll dare use it again. It chipped cutting cardboard... not battoning or chopping wood.

It looks as though it could be covered by the warranty, provided they decide the damage wasn't caused by abuse. It would be their call. You might try contacting Rockstead directly just to check off that box.

You could also try contacting JasonB on the forum here. He has professional sharpening experience with Japanese knives. Or Josh at Razor Edge Knives, also on the forum. He's excellent. Or maybe companies with high-end sharpening services, like ChefKnivesToGo, which does high-end sharpening for the knives it sells. It may do yours, or maybe it could steer you to another service.

The other problem is that you picked ZDP 189, which is run at a super hard 67 Rc. Their tougher steel would have been a better choice. But you'd probably want to fix the chip before selling so you do not lose too much on the transaction.

WARRANTY INFORMATION
◆Rockstead warrants the sharpness of the blade. If your knife doesn't cut well, please send it to our company.


◆Rockstead warranty doesn't cover damage caused by abuse, misuse, loss, improper handling, alterations, accident, neglect, disassembly, or improper sharpening.
 

Berengir

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It looks as though it could be covered by the warranty, provided they decide the damage wasn't caused by abuse. It would be their call. You might try contacting Rockstead directly just to check off that box.

You could also try contacting JasonB on the forum here. He has professional sharpening experience with Japanese knives. Or Josh at Razor Edge Knives, also on the forum. He's excellent. Or maybe companies with high-end sharpening services, like ChefKnivesToGo, which does high-end sharpening for the knives it sells. It may do yours, or maybe it could steer you to another service.

The other problem is that you picked ZDP 189, which is run at a super hard 67 Rc. Their tougher steel would have been a better choice. But you'd probably want to fix the chip before selling so you do not lose too much on the transaction.

WARRANTY INFORMATION
◆Rockstead warrants the sharpness of the blade. If your knife doesn't cut well, please send it to our company.


◆Rockstead warranty doesn't cover damage caused by abuse, misuse, loss, improper handling, alterations, accident, neglect, disassembly, or improper sharpening.
According to the seller, this is "improper handling".
Not quite sure what he meant:

"Such breakouts do not occur during cutting, but during tilting. This can happen from time to time. You have to work very precisely with the ZDP.
That is the big difference. This steel requires a more precise, attentive handling and precise guiding of the knife than other steels. But then you will enjoy it even longer."

And indeed, I should have gone with the other steel. I let my eyes pick instead of my brain
 

Twindog

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According to the seller, this is "improper handling".
Not quite sure what he meant:

"Such breakouts do not occur during cutting, but during tilting. This can happen from time to time. You have to work very precisely with the ZDP.
That is the big difference. This steel requires a more precise, attentive handling and precise guiding of the knife than other steels. But then you will enjoy it even longer."

And indeed, I should have gone with the other steel. I let my eyes pick instead of my brain

It's difficult for me to believe that cutting cardboard will chip the steel without "precise, attentive handling and precise guiding." If that's true, Rockstead should provide a warning to all potential buyers.

My go-to cardboard-cutting knife is a custom made by Bluntcut out of Rex 121. It's very thin and as hard or harder than Rockstead's ZDP 189. It has never chipped, and I don't worry about being extra careful cutting cardboard.

If Rockstead agrees with this seller's advice, I'd never buy a Rockstead in that steel. Who would? Collectors, I suppose.
 
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"Such breakouts do not occur during cutting, but during tilting. This can happen from time to time. You have to work very precisely with the ZDP.
That is the big difference. This steel requires a more precise, attentive handling and precise guiding of the knife than other steels.

BS !! If that is the case they should incorporated this in the knives they sell !!!

ZbB2PkL.jpg


You pay $$$$ and you get that answer ????
 

Berengir

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BS !! If that is the case they should incorporated this in the knives they sell !!!


You pay $$$$ and you get that answer ????

Excellent suggestion. Good thing I always carry my Pocket Level!

20190828_092217_zpszfhhhvyo.jpg

This will make cutting much easier ;)
 

Berengir

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Small update:

Decided to bite the bullet and try sharpening it myself. If it went wrong, I could send it back to Japan.

Took my trusty drywall hand sander, put some 2.000 grit sandpaper and oil on it, and started sharpening.

Took me about 20 minutes of gentle sharpening to get the chip to disappear.
Stropped it on a leather strop with 0.5 micron diamond spray, stropped it on the denim strop.
End result: razorsharp knife, push-cuts through magazine paper, no more chip but slight scratching near the edge.
As I'm no where near a freehand sharpening expert, I was expecting that.
It's a working knife for me, so the slight scratches (purely visual) don't bother me at all. (Don't kill me).

Back into my pocket it goes. I don't have to worry, if it chips again, I can fix it, and when it dulls, I can sharpen it. :thumbsup:
 

woodysone

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Small update:

Decided to bite the bullet and try sharpening it myself. If it went wrong, I could send it back to Japan.

Took my trusty drywall hand sander, put some 2.000 grit sandpaper and oil on it, and started sharpening.

Took me about 20 minutes of gentle sharpening to get the chip to disappear.
Stropped it on a leather strop with 0.5 micron diamond spray, stropped it on the denim strop.
End result: razorsharp knife, push-cuts through magazine paper, no more chip but slight scratching near the edge.
As I'm no where near a freehand sharpening expert, I was expecting that.
It's a working knife for me, so the slight scratches (purely visual) don't bother me at all. (Don't kill me).

Back into my pocket it goes. I don't have to worry, if it chips again, I can fix it, and when it dulls, I can sharpen it. :thumbsup:
Good on you for biting the bullet and sharping it. My Chi isn’t sharp any longer and didn’t want to try getting the convex edge back, you may have pushed my into giving it a try:eek:;)
 

Berengir

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Good on you for biting the bullet and sharping it. My Chi isn’t sharp any longer and didn’t want to try getting the convex edge back, you may have pushed my into giving it a try:eek:;)

I've always found convex edges easier to sharpen than straight edges.
I'm not sure about the Chi, does it have a convex edge as well, seeiing as it's a tanto shape?
 
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I ordered a Sai Tanto today! It was the only one at Heinnie Haynes. They've sold 3 others. I told myself the sensible choice would be a YXR7 Tei...but the heart ruled the head, and I chose a ZDP.
 
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