Need a little help maintaining my ZDP-189 blade...

[Bolster]

I have been giving my Caly Jr in ZDP-189 a lot of use lately, while refurbishing a house. It gets called on for a variety of cutting (but no scraping or prying) tasks, from cutting masking paper to woodworking to cardboard to pruning...basically, a wide variety of cutting tasks, in and out of my pocket many dozens of times a day.

My problem is that I am having difficulty keeping it sharp. The edge is back-beveled around 12 degrees per side, and then the microbevel is applied at 15 degrees per side with the Sharpmaker. I can get the blade sharp enough to cut arm hair, yet it never slices paper as cleanly as my VG-10, tends to stick and hang-up more, usually half-way or 2/3 the way down a free hanging sheet of 20-lb bond paper.

Oddly, after a day's work, it seems remarkably dull, for what I would consider normal usage (no running it into plaster or cement, etc). (I switch out with a Caly III in VG-10 which is my comparison knife). Having read of edge fatigue, I ran the edge parallel to the stone to get rid of the old edge and brought it back to a new one. In retrospect that was just a whole lot of work...didn't seem to make any difference in edge holding.

Bringing it back to acceptable sharpness (meaning, just able to shave arm hair, or being able to make it 2/3 of the way through a sheet of hanging test paper with minimal sawing action) can take me 50 swipes each side of the blade on the corners of the medium stones or more, and I have to do this every night! This is followed by 20+ on the fine, and another 20+ on the ultrafine. (Sometimes I could swear that my cutting ability is somewhat lessened after using the fine and UF stones.) I have tried fewer swipes on the fine and UFs but that doesn't help, either. Seems if I do a few on the fines or UFs, I need to do 20 or more.

I suspect I am spending too much time sharpening this knife, and I further suspect something's wrong with my technique. What works great for my VG-10 is not giving me the same results on the ZDP. Can you help me figure it out?

[pedro navaja]

I'm not a sharpening expert but I had a similar situation with an Endura zdp and I went to a coarse dmt stone, then dmt fine and after to the sharpmaker on the grey stones at 15. sometimes a few passes on the fine rods but I think it is best to finsh with the grey stones; by the way I learn this approach here inthe forum

[Left Hand Path]

Unfortunately, Bolstermanic, I am not able to give you any help on ZDP. My experience with ZDP is VERY similar to what you are describing. I have never been able to get ZDP up to the push-cutting ability of my VG-10 knives, either. Your description of re-sharpening on the Sharpmaker matches my experience perfectly. ZDP has definitely frustrated me, and I feel like I am not getting the maximum performance out of it.

I will watch this thread with interest.

[bladese97]

:spyder: :spyder: :cool: :spyder: :spyder: I'm not an expert either, but got some great advice from some Awesome Spyderholic forumites, and here's roughly what they told me; Take a few passes, holding the blade verticaly over a horizontal course stone, and make a few passes to get rid of the useless metal/burr that forms from use; Then make passes on the White stones on the Sharpmaker, until hair poppin edge is acheived :) :cool: I have mine all done; It takes alittle time, but worth it :D

[SimpleIsGood229]

I'm not an expert (nor do I play one on T.V.), but I do think diamond stones are in order. For my Krein re-ground ZDP Endura, I use DMT Coarse, then Fine diamond stones. I finish it off with a Lansky Ultra Fine ceramic. I've had very good results with that. Yes, it does take many more swipes than VG-10.

As far as edge angle, I really can't help you much there, since I sharpen free-hand.

I'm sure yablanowitz will be here shortly. :)

[stoneman]

I don't have any experience with zdp-189 but i found that the finer the grit of stone, less pressure is required when sharpening. Don't know why this is the case, but since I lightened up a bit on the finer stones, my blades tend to get sharper. Good luck

[palehorse]

Unfortunately, Bolstermanic, I am not able to give you any help on ZDP. My experience with ZDP is VERY similar to what you are describing. I have never been able to get ZDP up to the push-cutting ability of my VG-10 knives, either. Your description of re-sharpening on the Sharpmaker matches my experience perfectly. ZDP has definitely frustrated me, and I feel like I am not getting the maximum performance out of it.

I will watch this thread with interest.

Ditto all of that.
Perhaps sharpen it with a medium grit only. Some of my handmade
knifemaking buddies tell me that leaves micro-teeth on it and it will
cut and cut and cut and cut and cut and cut and cut and cut and cut.

[LowTEC]

My caly Jr ZDP is the sharpest push cutter out of all my collection, the key is LOTS of swipes, starting with brown stones if there was any dull, rolled, or chipped. The ZDP can definitely takes lower than 30 degree inclusive, I would say around 20-25 degree inc. is ideal. The key is lots of med-light strokes of the brown and followed by some 100-200 light swipes on the white's flat. and the last 20 or so swipes has to be next-to-no-pressure for maximum sharpness. it surely does takes longer to sharpen, but the edge holding capability of ZDP is simply ridiculous and it will last 5 if not 10 times longer than my caly VG10. Good luck practicing

[telemeister]

I've got the Caly 3 CF and I can get that scary sharp using the 40 degree stones. I don't seem to have the same problems with the ZDP steel (the Byrd steel is another issue though!!). As for retaining the edge, I think that the edge won't last nearly as long using the 30 degree setting, but you should still be able to get it very sharp.

Its funny that you ask this question, because I have been having trouble getting my SAK and my Byrd Flight really sharp, yet all of the Spydies I have sharpened (VG-10, Aus 6, CPM-S30V) have been really easy to get sharp.

[yablanowitz]

I'm afraid I won't be much help. I use my Sharpmaker for serrations, and that's pretty much all. The ZDP blades (and everything else not serrated) get sharpened freehand on my various DMT hones. I generally start with coarse (unless it is really chewed up) and work down to extra-fine (9 micron). Edge angles on my work knives are closer to forty than twenty degrees included. That may be sacreligious to some, who feel the great advantage to the high end steels is the ability to hold a stable edge at smaller included angles, but I use mine hard enough to tell the steels apart at forty.

ZDP-189, while quite hard, is not all that abrasion resistent. It does feel different on the hone, like it is sliding across the surface instead of being abraded, which can sucker you into using too much pressure. I made that mistake at first. Now I keep the pressure very light and trust the diamonds to do their job. Guess what? They do. It does take a lot more strokes for ZDP than it does for VG-10, but I don't even bother with VG-10 for my work knives, it just doesn't stay sharp enough long enough to bother with for me. And for all of you about to protest that dismissal, remember how many times I've said my use is NOT typical. :D

[Bolster]

Thanks for the good replies, but y'all are too modest. If you guys aren't experts, who is?

I should have said in the original post: I really do lighten the swipes on the white stones, and don't go to heavy on the brown stones either. The final swipes are just whispers.

Question: ZDP doesn't develop the wire edge of other steels, right? (Can't say I've ever felt my ZDP edge was "sharper from one direction than the other," which is usually the tipoff that a wire edge has formed.) Which calls into question any stropping-like work, and also the idea of a fatigued wire edge...does it not?

What I'm learning, and am going to try after studying this thread:

- Start AND finish my touchups on the brown stones; skip the white stones for now.

- If that doesn't work, get the diamond stones for the Sharpmaker and try those.

- Don't sweat it if I'm taking 50 swipes on the brown stones; it might take a hundred or more.

[LowTEC]

I personally wouldn't suggest to skip the white stones, I found there is a huge difference in finished sharpness between the brown and white. It is right that the brown stone will give you the "saw" like finish, but that is not what ZDP-189 is famous for (leave that for D2), the white stones would give you a split hair like push cut capability which the brown is simply too coarse (relatively speaking) for such task. my humble 2 cents.

[yablanowitz]

Yes, ZDP-189 can and will form a wire edge. In fact, it can be a pain to get rid of that burr. My first sprint run ZDP Delica had a wire edge from the factory. It was literally razor sharp...for about thirty seconds when I started using it at work. That wire edge rolled at first contact with dried mastic adhesive.

[Native Justice]

I agree with the others. Take the old steel down with the diamonds to get to the new steel. Create your new bevel with the diamonds then go thru your progression of ceramics finishing with increasingly lighter strokes. DON'T forget to strop and remove that wire edge. DON'T forget to gently create a micro secondary bevel (3-6 light strokes per side) with your UF hones at 15' (assuming your primary edge is at 12') or even better still, if you're using it hard, take it up to 20'. DON'T leave a coarse edge with micro teeth. Most of the experts all agree that a polished edge on virtually all edges will insure a longer lasting stronger edge.

Best of luck.

NJ

[Billy]

Unfortunately, Bolstermanic, I am not able to give you any help on ZDP. My experience with ZDP is VERY similar to what you are describing. I have never been able to get ZDP up to the push-cutting ability of my VG-10 knives, either. Your description of re-sharpening on the Sharpmaker matches my experience perfectly. ZDP has definitely frustrated me, and I feel like I am not getting the maximum performance out of it.

I will watch this thread with interest.

Me three! I have no problems getting S30V, D2, BG-42, H1 or VG10 hair popping sharp, but that **** ZDP gives me fits! I finally gave up and sent my Caly Jr. back to Spyderco for a fresh factory edge. I will not use it again until I get the necessary diamond rods for my Sharpmaker. If that doesn't work, then I guess I will have to go freehand with some DMT stones.

[Michael Cook]

:spyder: I hate zdp-189, I'll not buy any more blades in said steel. Based on what I've heard I won't buy any s90v knives either. :spyder:

[HoB]

Not claiming to be an expert but I get my ZDP-189 Caly sharper than any other stainless steel knife. I use, however, waterstones.

My experience with ZDP is, that it burrs very little, so you don't have to worry about that much. This is why I very much doubt that you have a wire edge giving you problems. But ZDP tends to chip on hard abrasives, very similar to the very hard carbon steels in traditional japanese kitchen knives, which is why it response so well to waterstones. These chips is likely the reason as well, why the edge doesn't last (btw. don't mistake that with microchipping. That is a different thing). But I found it is possible to sharpen on the Sharpmaker as well. First I would suggest, not to use the corners at all and secondly to go really light on the gray stones.

First clean of the edge, that you have right now by stropping, best on loaded leather, if you don't have that, use the cover of you telephone book, and unlike normal stropping, put some pressure on the blade. You don't want the sharpest edge, you want to smooth out what ever edge you have on right now. Take may be 30-50 strokes each side. You don't have to pay much attention. Then take *very light* strokes on the flat side of the grays. Be prepared to do instead of the usual 20 strokes per side at least 50. ZDP is very abrasion resistant and needs a little bit more effort and you are skipping the corners. So you have to do those 20 strokes on the flats as well. The white rods are much less of a problem with ZDP, you can give it a little bit more pressure, but I would still recommend to go very lightly. Again this is not because of a wire edge but because you don't want to run a very hard edge into a hard abrasive. You can also try a trailing motion on the Sharpmaker (dragging the knife from the bottom to the top).

That should do it. For maximum pushcutting ability, strop on your rolled up phone book or regular strop with light strokes at the same angle.

[Billy]

:spyder: I hate zdp-189, I'll not buy any more blades in said steel. Based on what I've heard I won't buy any s90v knives either. :spyder:

I agree - I would rather have a knife that I can take from dull to hair popping sharp quickly and proficiently even if the edge-holding is not quite as good. Funny thing is, I've found my BG-42 Millie to hold a really good edge for a really long time. Probably even longer than my ZDP Caly Jr. Doesn't take an unusual amount of effort to bring it to SSS (Stupidly Sharp Status - yup, I just made that up!) either.

[Mr Blonde]

I had some difficulties with ZDP 189 on the Sharpmaker as well. I managed to overcome it though. I spend a little extra time to find out what's really going on at the edge, using the right angle where both sides 'meet'. That, and I'll second the tips on using light pressure. I have an easier time getting ZDP edges just right (from sharp to really sharp), since I use my UF hones.

Wouter

[bladese97]

:spyder: :spyder: :cool: :spyder: :spyder: I've resharpened my Stretch2 twice, and though it took a little more time, it was not hard; Even for me :rolleyes: :D