Keeping ZDP factory sharp

[jackknifeh]

I got a Spyderco Michael Walker a couple of weeks ago that has ZDP-189 steel used for the blade. According to what I’ve read it has a Rc hardness of 64 – 66. That is harder than anything I’ve ever tried to sharpen. When I got it, it had a razor sharp edge on it. I used it a lot and even did a lot of cutting just to see how long it would hold a great edge. The edge retention was better than any knife I’ve ever owned. After cutting lots of cardboard, whittling different types of wood, etc. the knife finally lost the razor edge but was still sharp. I touched up the edge at the factory angle and got the razor edge back with no problem.

Then I lowered the angle a couple of degrees to 18 degrees (per side). I use an Edge Pro sharpener with Japanese water stones and polish tapes to get a good mirror finish. It took considerable time to finally get to the point where I was sharpening the edge. I sharpened it until I could get a burr on both sides then I would change to a higher grit all the way up to 1000. After that I’ve used your tapes and then even an old leather strop I have but I can’t get the edge back to the sharpness it had (and I was able to maintain) when it was brand new. I was wondering if anyone had any ideas about why I’m having a problem with this knife. I was thinking I might not be spending enough time with each grit. If that’s the case that is fine. If the blade holds up against stones that are designed to cut steel that well that is a good indication of it’s edge retention when using the knife for normal cutting. Any thoughts you have would be appreciated.

Thanks,
Jack

[ChapmanPreferred]

To the original poster, glad you were able to use the 30 degree setting and touch up your edge.

To Jack, How much pressure are you using with the stones? I have found that a lighter touch with more strokes will produce less of a burr which you would be easier to strop away. Do you have any cutting media on the leather strop? I would guess diamond spray would do a good job with ZDP, but I have never used it. I just use green or white rouge on leather.

[jackknifeh]

In my last post I said I was lowering the angle on a ZDP-189 blade to 18 degrees. Even after I got the edge down to where I was creating a burr on each side I couldn't finish the edge and have it very sharp. I contacted the maker of the Edge Pro sharpener and he said getting razor sharp edges at low angles on the harder steels is difficult and he explained why. I raised the angle to 21 degrees and once again have the razor edge that came on the knife and can keep it ther with ease. I have an Endura 3 with a VG-10 blade and can get a razor edge at 18 degrees very easily

If anyone out there has been able to go down to 18 (or lower) degrees on a ZDP blade I'd like to hear how you achieved it.

[Brisket]

Then I lowered the angle a couple of degrees to 18 degrees (per side).

If anyone out there has been able to go down to 18 (or lower) degrees on a ZDP blade I'd like to hear how you achieved it.

jackknifeh,

The folks referencing 30 degrees with the Sharpmaker are talking about 30 degrees inclusive (15 degrees per side) because of the 30 and 40 degree marked rod positioning holes in the base of the unit. With high performance steels such as with the ZDP-189 discussions about edge angle can often be confusing because it can function at such aggressive angles. If someone mentions sharpening 440c at 20-25 degrees one can be fairly certain they are talking about per side. With ZDP-189 not so much.

I maintain my ZDP-189 edges at about 15 degrees per side and have read accounts of people taking them down to around 10 degrees.

[Grizzled Gizzard]

Yeah Chuck, 22 degrees inclusive is no problem with ZDP, provided you are not needing heavy or abusive work from the blade. The increase in sharpness can be amazing if the angles are matched up correctly, and the burr removed properly.

I've found the burr isn't really difficult to get rid of with ZDP. At these thin edges it's difficult to spot sometimes, and I feel for it on my fingernail.

A good diamond on leather strop can take care of the final burr and make the edge well beyond store bought razor type sharp.

The chrome carbides in ZDP have a different feel to say, Vanadium, or tungsten carbides. The result is a smoother edge at extremely high grits than, say, S90V. The "killer V" steels resist abrasion more especially during hard use but IMO, they will never take the extreme "darksider" edges possible with plain carbon steels, and some ( very , very few high carbide steels) such as ZDP.

Yep, I'm still amazed by ZDP even after using it for several years now, and owning over a dozen knives made from it.

Like anything else the more you work with it, and the harder and more extreme you push it, the more ZDP will reveal of itself to you.

Regards, Joe

oooooooohhhh yyyyyyeeeeeaaahhhh.... That's what I was wanting to hear.

[Grizzled Gizzard]

I got a Spyderco Michael Walker a couple of weeks ago that has ZDP-189 steel used for the blade. According to what I’ve read it has a Rc hardness of 64 – 66. That is harder than anything I’ve ever tried to sharpen. When I got it, it had a razor sharp edge on it. I used it a lot and even did a lot of cutting just to see how long it would hold a great edge. The edge retention was better than any knife I’ve ever owned. After cutting lots of cardboard, whittling different types of wood, etc. the knife finally lost the razor edge but was still sharp. I touched up the edge at the factory angle and got the razor edge back with no problem.

Then I lowered the angle a couple of degrees to 18 degrees (per side). I use an Edge Pro sharpener with Japanese water stones and polish tapes to get a good mirror finish. It took considerable time to finally get to the point where I was sharpening the edge. I sharpened it until I could get a burr on both sides then I would change to a higher grit all the way up to 1000. After that I’ve used your tapes and then even an old leather strop I have but I can’t get the edge back to the sharpness it had (and I was able to maintain) when it was brand new. I was wondering if anyone had any ideas about why I’m having a problem with this knife. I was thinking I might not be spending enough time with each grit. If that’s the case that is fine. If the blade holds up against stones that are designed to cut steel that well that is a good indication of it’s edge retention when using the knife for normal cutting. Any thoughts you have would be appreciated.

Thanks,
Jack

If you aren't sharper than factory at 1k, something ain't quite right. I know it sucks, but I've had it happen.

You have two choices- Either resharpen now, or use the edge as is, then resharpen. Obviously, one makes a little more sense than the other, but I've been there, and gone back to 220 for just a minute, then worked it back up, paying closer attention to holding the blade solidly. This hasn't failed to improve things yet, so I guess that tells me something.

[Grizzled Gizzard]

To the original poster, glad you were able to use the 30 degree setting and touch up your edge.

To Jack, How much pressure are you using with the stones? I have found that a lighter touch with more strokes will produce less of a burr which you would be easier to strop away. Do you have any cutting media on the leather strop? I would guess diamond spray would do a good job with ZDP, but I have never used it. I just use green or white rouge on leather.

Something just dawned on me from your post, CP. When using the EP, if I'm concentrating on holding the knife more solidly, I'm probably trying to put less pressure on the stone by default. There's probably something to that.

I haven't even tried stropping my ZDP yet. Just lazy, and anxious to test it at 6k. I can tell you though, that I do think .5 mic diamond works faster (less stropping) than CrO on M4... I think. I'm getting kinda old though, and things really have to be going right for me to make that kind of determination. Even then, how the knife comes off the polish tape may be more significant. It's kinda hard for me to tell sometimes.

I tend to go with conventional wisdom, and how I "feel". I have different hones and the different diamond sprays, but I'm pretty sure that it generally comes down to how the operator is doing. That's definitely the biggest variable in my shop.

[pippert]

I've read these posts with a lot of interest as I'm thinking about stepping up to the ZPD steel. I appreciate everyone's expertise and experience.

As others have said, my concern is keeping the blade sharp as it can be. I rarely let my blades get too dull and have always used ceramic rods (from A.G. Russell) to keep my knives sharp and wonder if that would be sufficient to keep the ZPD at it's peak. Any thoughts?
Thanks for your help.

[jackknifeh]

Hello,

I've had a Michael Walker w/ZDP blade for about a month now. I also have an Edge Pro sharpener which I bought a couple of months ago. I've had a tough time getting an edge on the blade that satisfied me. This after noon I finally got a great edge on the blade using the Edge Pro. I think my problems came from a new steel and sharpener at the same time. I've learned quite a bit about how to get good results. I think with the ZDP I just needed more patience. That's a good thing because if you could cut the metal off the blade very quickly that would indicate the metal is soft enough that an edge would be lost quickly. Anyway I am very happy with the ZDP now and have ordered a Stretch knife with a ZDP blade. Since receiving the knife I've been happy with the blade as far as edge retention and cutting ability. It was just the sharpening that was giving me trouble. Now I really like the ZDP and recomment it to all. I must say that for the last 4 years I've been using diamond stones and now Japanese water stones both of which work a lot faster than the Arkansas stones I've used all my life. Sharpening a ZDP blade with standard inexpensive wet stones would drive someone to drink...more.

Jack

[Ankerson]

Once you get it sharp just make sure to touch it up and don't let it get too dull.

I have an Endura 4 FFG in ZDP-189 and it does hold an edge extremely well.

[LowTEC]

I like to keep my ZDP blades at 17" inclusive. Wanted to go even lower but the blade body (Para CPMD2) got really scratched up if my hand is not perfectly steady. So I decided not to ruin the finish of my Stretch ZDP and kept it at 17 degree inc. instead. Don't stop at 30 inc. degrees as you are not even close to feel the potential performance of the best steel in the world

[Ankerson]

I like to keep my ZDP blades at 17" inclusive. Wanted to go even lower but the blade body (Para CPMD2) got really scratched up if my hand is not perfectly steady. So I decided not to ruin the finish of my Stretch ZDP and kept it at 17 degree inc. instead. Don't stop at 30 inc. degrees as you are not even close to feel the potential performance of the best steel in the world

I might go lower on mine if I get in the mood to really move some steel. :D

Something like 10 degree per side. :eek: :D

[jackknifeh]

Hello LowTEC,

You said not to stop at 30 degrees inclusive and you like 17 degrees inc. I had problems sharpening the ZDP at first but now have no problem with it. It just takes a little more patience it seems to me. I've got my Stretch to 30 degrees inclusive and am very happy with it. I was just wondering what you are cutting that a lower angle is beneficial. I would think it would be something like shaving (face, not just arm hair). I'm not going lower on my Stretch because I use it as a work knife as well as EDC. I don't use it for HARD work. I have a fixed blade that I use when I want to have fun really abusing a knife. I have a smaller ZDP blade knife I may want to lower the angle on if I feel it will be beneficial.

I would appreciate input from anyone on the benefit of very low angles.

Thanks,
Jack

[ccf]

I have a question. Somebody mentioned something about Spyderco knives coming with a 30 degree angle (which I knew), but they recommend a 40 degree angle when you resharpen (which I didn't know). Is this correct? Or is that wrong?

If it's true, why does Spyderco sharpen at 30 but recommend resharpening at 40? Just trying to learn the concept.

[chuck_roxas45]

I think that it's because they aim for 30 degrees or less but sometimes it's more so 30 degrees on the sharpmaker doesn't always hit the edge. 40 degrees always hits the edge.

[jackknifeh]

I agree with chuck about the sharpening angle that Spyderco puts on a knife and why. Also, since lower angles are usually more desireable Sypderco is saving it's customers the time it takes to reprofile an edge down to 30 degrees if they wanted to. Also trying a knife out of the box with a 30 degree angle will give immediate satisfaction to a customer that doesn't care anything about angles. They just want a sharp knife.

I've talked to a guy who has been sharpening knives for a living for over 30 years and he says that most of the pocket knives he sharpens for people are about 40 degrees inclusive. Whether they came that way at first is unknown.

Jack

[unit]

I might go lower on mine if I get in the mood to really move some steel. :D

Something like 10 degree per side. :eek: :D

I am planning on reprofiling my ZDP blade this weekend. I can not decide what I am going to do yet...10 DPS is the largest option I am even considering. There are many claiming great results with very low angles on this steel.

[chuck_roxas45]

I am planning on reprofiling my ZDP blade this weekend. I can not decide what I am going to do yet...10 DPS is the largest option I am even considering. There are many claiming great results with very low angles on this steel.

I'll be waiting on that video.

[swanseajack]

I noticed that ZDP likes my fine Lansky diamond hones used very gently at the final stage of sharpening too..
I only go down to 20 degrees per side and it is certainly sharp enough for me, probably sharp enough for Luke Skywalker..

[unit]

I'll be waiting on that video.

Thanks, I have some ideas, but I am not sure if they will work out or not...I will keep you posted.