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ZDP hard to sharpen?!?!

Colog

Colog

Joined
Dec 2, 2005
Messages
1,341
I sharpened 3 knives today. A Buck 295, with a 420 HC blade, a spyderco with an ATS-55 blade and a Kershaw leek TI/ZDP.

I sharpened them each with an Edge pro apex on the green mark (18 degrees). The Buck took about 10 minutes to go through all the stones, developed a large bur very quick, super easy to sharpen. The spyderco was about the same, developed a noticeable bur very quickly. Both are now razor sharp.

Then I switched to the zdp leek. It took me about an hour to work through the stones. Never developed a large bur. I could feel it, but nowhere near the bur on the other 2 blades. So whats that? About 6X as long? Is that normal for ZDP? The zdp blade is extremely sharp. Seems sharper than the other 2 blades. Just seemed like a lot of work. Is this typical of zdp? Or did I just mess up somewhere along the way?
 
ZDP is generally VERY hard (I don't think that any other cutlery steel is as hard as ZDP normally is), and thus it'll be tougher to sharpen.

So, you're doing fine.
 
Peter_E_Ryt said:
ZDP is generally VERY hard (I don't think that any other cutlery steel is as hard as ZDP normally is), and thus it'll be tougher to sharpen.

So, you're doing fine.
Click to expand...

Ok, thanks for the reply. I knew ZDP was some kind of super steel, but I didn't think it would be so hard.
 
even S30V takes a lot of work. I only noticed it when I sharpened AUS8 at the same time. the AUS8 steel was easy peasy.
 
spyken said:
the AUS8 steel was easy peasy.
Click to expand...

Lol,.try 420 HC. The Buck I did had a pretty big chip in the blade. I worked it for a minute with the course stone, looked at the blade and said WTF happened to that chip. It was gone.
 
Colog said:
Lol,.try 420 HC. The Buck I did had a pretty big chip in the blade. I worked it for a minute with the course stone, looked at the blade and said WTF happened to that chip. It was gone.
Click to expand...

Same thing happens when you take some nice printer paper to 420 HC. Work for a minute slicing the paper, look at the blade and it's WTF happened to that edge that was razor sharp just a minute ago.

Steel sharpening is a give and take sort of thing. I spend a long time on my ZDP edge, but it spends a looooong time cutting.
 
Wait till you guys have to reprofile or do some major work on S90V. ZDP seems easy in comparison to me. Joe
 
you say you sharpened them all at the same angle but did they all have 18 degree bevels to start with? If not the ones that were not at 18 degrees got reprofiled and any edge that was already at that angle would have been much easier to sharpen regardless of the steel since only a very small amount would need to be removed. If the ZDP was on its first sharpen and the other knives had been sharpened at this angle before that would be a major reason for the time difference. ZDP is usually brought to a higher hardness and may have lower grindability but that much difference in time makes me wonder if its the steel or the angles.
 
BigJimSlade said:
you say you sharpened them all at the same angle but did they all have 18 degree bevels to start with? If not the ones that were not at 18 degrees got reprofiled and any edge that was already at that angle would have been much easier to sharpen regardless of the steel since only a very small amount would need to be removed. If the ZDP was on its first sharpen and the other knives had been sharpened at this angle before that would be a major reason for the time difference. ZDP is usually brought to a higher hardness and may have lower grindability but that much difference in time makes me wonder if its the steel or the angles.
Click to expand...

I would agree that the Leek was probably over 18 per side and most of the time spent was reprofiling. If you have a thin backbevel and use microbevels ZDP actually sharpens up quickly.

Mike
 
Colog said:
I sharpened 3 knives today. A Buck 295, with a 420 HC blade, a spyderco with an ATS-55 blade and a Kershaw leek TI/ZDP.

I sharpened them each with an Edge pro apex on the green mark (18 degrees). The Buck took about 10 minutes to go through all the stones, developed a large bur very quick, super easy to sharpen. The spyderco was about the same, developed a noticeable bur very quickly. Both are now razor sharp.

Then I switched to the zdp leek. It took me about an hour to work through the stones. Never developed a large bur. I could feel it, but nowhere near the bur on the other 2 blades. So whats that? About 6X as long? Is that normal for ZDP? The zdp blade is extremely sharp. Seems sharper than the other 2 blades. Just seemed like a lot of work. Is this typical of zdp? Or did I just mess up somewhere along the way?
Click to expand...

This only mean that ZDP is way better then 420 and ATS55 in sharpening. Big bur is sign of soft steel the better steel - smaller bur you have. And smaller bur - better to sharpen, because abrasive most likely take steel away instead of bend it and form wire edge. This is true for all premium steel with proper HT.

You need burr as indication that you sharpenning effort hit the very edge and does not matter how big it is - the smaller the better. You may have much finer edge in result.

IMHO.

Anyway on my experience ZDP-189 is excellent for sharpen, however I always use diamond sharpening, even before ZDP hit the market.

Thanks, Vassili.
 
Most of the time ZDP is used in a "warikomi" sandwich with a thin ZDP core and some softer steel on the exterior. I is almost necessary to have blades made in warikomi style with a steel as hard and brittle as ZDP. Because the the thinness of the core, my own ZDP knives sharpen up pretty easily. I can see how it would be a struggle to grind it if it were full blade thickness.
 
Hi Colog,

I find that ZDP takes longer to profile, solid or laminate. Not nearly as difficult to "keep sharp".

sal
 
What nozh and Sal said. Large burrs are not an indication of good sharpening progress. I rebeveled my Cyclone to 12 deg per side and it too a good while on the stones. Now that it is 12 deg. per side. A few swipes on the Sharpmaker at 15 deg is all it needs. That is why I really like ZDP. It burrs very little.
 
We already have thread about it - all this talks about good steel being hard to sharpen is kind of anti-PR I think. I can imagine this only if steel came harder then abrasive - this happen to me only once when I have problem sharpening CPM S90V with less then 3 micron abrasive. This steel has a lot of Vanadium Carbides - 9% around 3 micron sizes which are harder then Ceramic and so when I try Spyderco Ceramic Fine rod it did not make any changes, but at this size only - medium rods work.

Other problem I have with sharpening is cheap Higonokamy knife with Shirogamy bit overhardened - Ceramic was to hard and make brittle steel chips. Soft water stone fix it instantely.

But I never have problem sharpening premium steel or have it being noticible harder. Of course I use best sharpening tools - diamonds. But my sharpening test side by side with Buck 110 knives I have with different steels 420HC, BG42, CPM S30V and CPM154 (new PM variant of old 154CM) - show that it is more easy to sharpen BG42 then 420HC.

I think this "hard to sharpen" is just silly argument started by some manufacturers which do not able to use best steel to cover their use of not so premium steels. I think for them it will be fair to say that their steel choise perfectly meet their quality level and do not talk about premium steel hard to sharpen by average Joe.

BG42 also form small bur, as well as Boss hardened A2 and ATS34. I guess biggest burr you will have if you try to sharpen steel spoon or something this nature. Again I sharpen ZDP189, both warikomy (this is right Japan word for laminated blades - not SanMay!) and solid - no problem at all. I actually looking forward to see steel which will be impossible to sharpen as many claims - no luck so far...

Thanks, Vassili.
 
Colog said:
I sharpened 3 knives today. A Buck 295, with a 420 HC blade, a spyderco with an ATS-55 blade and a Kershaw leek TI/ZDP.

I sharpened them each with an Edge pro apex on the green mark (18 degrees). The Buck took about 10 minutes to go through all the stones, developed a large bur very quick, super easy to sharpen. The spyderco was about the same, developed a noticeable bur very quickly. Both are now razor sharp.

Then I switched to the zdp leek. It took me about an hour to work through the stones. Never developed a large bur. I could feel it, but nowhere near the bur on the other 2 blades. So whats that? About 6X as long? Is that normal for ZDP? The zdp blade is extremely sharp. Seems sharper than the other 2 blades. Just seemed like a lot of work. Is this typical of zdp? Or did I just mess up somewhere along the way?
Click to expand...

I'm not sure if you are aware that ZDP-18 has a Rc of 65 to 67,has 3% carbon and 20% Chromium (the rest of the composition is not disclosed by Hitachi).With a blade that hard, normally one would use diamond sharpeners which will get the job done in less time.

But according to the experts(sal) Zdp-189 can be sharpened using conventional methods:confused:
 
There are carbon steels that can still beet ZDP. Can't wait to see someone try to use tungsten carbide as blade steel!!!!!!
 
I tried to sharpen my Leek zdp-189 blade a few months ago. I got quite frustrated trying to get a edge burr. I recently got a couple diamond stones from EdgePro. I'm going to see if that will get me the result I am looking for.
 
I haven't sharpened it yet, but my ZDP Delica is the sharpest knife I've even owned.
 
I generally stay with DMT, I get better results than with ceramic stones on ZDP.
 
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