Rockstead shin zdp-189 67rc sharpening?

J

jayjaytuner

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Jun 27, 2008
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So I just ordered a rockstead shin zdp....sapose to have a Rockwell of 67....

can anyone recommend a ideal way of sharpening it without having to ship it to japan to be resharpened when the time comes.

Thanks for the help!
 
Well I dont have a rockstead or anything with 67hrc but I would just touch the edge up pretty often so it never has a chance to dull and give you a hard time to bring back the edge.
 
Strop it regularly, that should be all you need as long as you don't chip it.
 
im hoping that stropping will keep me setup for a while, just curious how one would go about it after stropping no longer takes it to where it needs to be
 
Try diamond stones. DMT is the best at those. They go up to 8000 grit, which should be good enough for most purposes. Or, a spyderco sharpmaker.
 
From what I've read on sharpening a hard steel like you mentioned, the diamond stones are the best route to go. I have the Lansky diamond stones, but it doesn't matter what brand you choose. The secret is to lightly use the diamond stone. Bearing down too hard will cause the steel to chip. You have to have patience and time to achieve a sharp edge. I've got several knives with ZDP and when it's time to put them on a stone, I know to take my time and it's gonna take a while. I really don't know what the HRC is on the ones I have.
 
Even at 67 HRC, any reputable aluminum oxide, silicon carbide or diamond hone will handle it (Norton's India, Crystolon or DMT respectively, for example). They're all substantially harder than even this steel. Natural (Arkansas) stones wouldn't be hard enough, in all likelihood. I'd looked at the mfr's web page a week or so ago, after seeing somebody else posting about these knives. The mfr actually suggests using wet/dry sandpaper (usually silicon carbide, sometimes aluminum oxide) on hard backing to sharpen/grind edges on these blades (see linked page below). That should work well also; personally, it's my favorite method. Their steels are heavy in chromium carbides, but not vanadium carbides, which are very hard; diamond might be better in that case.

I'd recommend not going too coarse in grit though, as that may exacerbate chipping issues at this high hardness. Keep grit finer, and pressure light.

http://rockstead.jp/maintenance/


David
 
I highly recommend Japanese waterstones. Many methods will work but none will compare to good waterstones on ZDP.
 
My Spyderco Delica in ZDP-189 is my only experience with the metal. It's definitely harder to sharpen than an average steel, but honestly it's not the monster that it's made out to be. Just takes a little longer. I've had success with DMT C and EF, as well as waterstones in 1k and 5k on that blade, and both worked fine. I've not spent very much time with this blade and I've been very careful. With the price of a Rockstead, I think I'd have to psych myself up to sharpen it and do a good job, while still being careful.

It's just a blade and I know how to sharpen common blade shapes. The price just messes with me mentally.

Brian.
 
Spyderco only runs ZDP to 63, it is much different at 67.
 
With the caveat that I've never seen on in person, from what I can tell from their advertising materials, pictures, and posts here, it looks like they do a convex grind all the way to the edge. Stropping will be your friend.

If you end up needing to thin out to correct the geometry at a later date, you will need to convert it to a flat grind on either the bevel or microbevel, or you can make a steeper convex microbevel, or you will need to grind the entire convex bevel face in order to match what the geometry was originally.

I'd be interested to see someone that owns a Rockstead chime in about the grind to see if I'm correct.
 
I thought they were sharpened on a EP?
 
Obsessed with Edges said:
The mfr actually suggests using wet/dry sandpaper (usually silicon carbide, sometimes aluminum oxide) on hard backing to sharpen/grind edges on these blades (see linked page below). That should work well also; personally, it's my favorite method.

http://rockstead.jp/maintenance/

David
Click to expand...

David, thanks for that link. That is a nifty looking "wedge roller" they use with the sandpaper.

And right above, how about that plug for my beloved denim strop (with metal polish no less)! I don't know about getting "Pikal" here in the U.S., but Mother's Mag works nicely. I would've thought that with that hardness they would've recommended stropping with diamond paste, or CBN spray, or...?

Andrew
 
AFAustin said:
David, thanks for that link. That is a nifty looking "wedge roller" they use with the sandpaper.

And right above, how about that plug for my beloved denim strop (with metal polish no less)! I don't know about getting "Pikal" here in the U.S., but Mother's Mag works nicely. I would've thought that with that hardness they would've recommended stropping with diamond paste, or CBN spray, or...?

Andrew
Click to expand...

Even at 67 HRC, the aluminum oxide in Pikal and similar polishes (Flitz/Simichrome, maybe Mother's Mag too) would still be plenty hard enough to handle it. The steel used in these knives is heavy in chromium carbides, but not the harder vanadium carbides, in which case diamond or CBN would've been better for high-polished edges. I've used aluminum oxide compound and Simichrome to strop D2 and ZDP-189 (both chromium carbide-heavy), and they do fine on those.

Kinda nice to see that the mfr's recommended maintenance relies on simple & inexpensive materials, like sandpaper and denim and 'cheap' polish (by their own description, which made me snicker a bit :) ). And their grind is apparently convex also; so the recommended method is a natural for it. Looks like they spent some hefty engineering $$$ on the fixture for the sandpaper, though. I'm pretty envious of that tool.



David
 
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hey guys, got some questions about sharpening rocksteads with zdp189 and yxr7 steel. when chipping have occured, can you regrind with spyderco sharpmaker? cant remember the grit on the white stone. which grit do you guys recommend for regrinding and sharpening these steels?
 
AFAustin said:
David, thanks for that link. That is a nifty looking "wedge roller" they use with the sandpaper.

And right above, how about that plug for my beloved denim strop (with metal polish no less)! I don't know about getting "Pikal" here in the U.S., but Mother's Mag works nicely. I would've thought that with that hardness they would've recommended stropping with diamond paste, or CBN

Andrew
Click to expand...


Pikal is Available at Ted Pella
 
beschcode said:
hey guys, got some questions about sharpening rocksteads with zdp189 and yxr7 steel. when chipping have occured, can you regrind with spyderco sharpmaker? cant remember the grit on the white stone. which grit do you guys recommend for regrinding and sharpening these steels?
Click to expand...

If the steel is chipping, I wouldn't recommend using a ceramic sharpener to try to fix it. It won't be aggressive enough (in grit size) to do heavy repairs like that, and the hardness of the ceramic may actually contribute to more chipping, if not expertly careful in using it.

The sandpaper method recommended on the Rockstead site is likely as effective as anything could be; in fact, perfect for the convex grind on them. Coarser grits of SiC or AlOx wet/dry sandpaper can do the edge repairs, and finer grits and/or stropping on denim with metal polish should work well for finishing up. As suggested by Jason B. earlier in the thread, waterstones might also be used, but that's a whole other level of expertise needed, to use them to best effect.

At the price point of those knives, you might also think about sending the knife back to Rockstead, and let them re-grind the edge for you. That'd probably be the safest option, and should also come with warranty coverage. If there's a QC issue contributing to the chipping, they should also take responsibility for that.


David
 
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Congrats on a very cool knife, I'm jealous.
If I understand their website correctly, the angle varies along the edge, from 30 degrees inclusive near the handle, to 24 at the tip. Pretty cool concept, added toughness where it's needed, and better cutting performance near the tip where there's less edge wear.
Together with the convex edge, it hardly makes for easy maintenance with sharpmakers, edge pros, DMT:s and the like, though. I'd strop it until it needs regrinding, then send it to Japan. Using the sharpmaker on it would be like putting re-treads on a Porsche, IMHO ;)
 
Obsessed with Edges said:
If the steel is chipping, I wouldn't recommend using a ceramic sharpener to try to fix it. It won't be aggressive enough (in grit size) to do heavy repairs like that, and the hardness of the ceramic may actually contribute to more chipping, if not expertly careful in using it.

The sandpaper method recommended on the Rockstead site is likely as effective as anything could be; in fact, perfect for the convex grind on them. Coarser grits of SiC or AlOx wet/dry sandpaper can do the edge repairs, and finer grits and/or stropping on denim with metal polish should work well for finishing up. As suggested by Jason B. earlier in the thread, waterstones might also be used, but that's a whole other level of expertise needed, to use them to best effect.

At the price point of those knives, you might also think about sending the knife back to Rockstead, and let them re-grind the edge for you. That'd probably be the safest option, and should also come with warranty coverage. If there's a QC issue contributing to the chipping, they should also take responsibility for that.


David
Click to expand...
Do you think 2000 grit wet sandpaper is enough or do I need higher?
 
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