How sharp can you get ZDP?

[gaj999]

I've sharpened up my mules. I sharpened them all at 10 degrees/side. 52100 easily tree tops, M4 tree tops, and the ZDP won't, no matter what I do. It does shave easily.

I've sharpened the ZDP three times on my EdgePro. I'm careful to raise a burr all the way across on both sides and then take it down through the grits to 600 and then I strop. The edge on the ZDP looked like it had some micro chips through a 20X magnification so I put a 15 degree/side micro bevel on with a Sharpmaker. It helped a bit, but it's still kind of dull.

Am I doing something wrong, or is this normal for ZDP?

Thanks, Gordon

[yablanowitz]

It is hard to be certain. My experience with ZDP tells me it is a somewhat finicky steel that doesn't respond well to pressure. Using my DMT diamond hones, I can get it as sharp as anything else now that I'm used to the feel. ZDP is hard enough that it feels as if it is simply sliding across the hone. I don't feel the "bite" of the abrasive action, but it is there. Once I learned not to press down hard enough to feel that bite, my edges improved dramatically. I just use very light pressure and a lot of reps, running from X-Coarse down to X-Fine.

[gunmike1]

I get ZDP hair whittling sharp easily. M4 gets a tad sharper for me, but ZDP 189 gets extremely sharp for me sharpening freehand on Shapton Glasstones and finishing on lapping film. A lot of times it is whittling hair off the 1000 grit Glasstone, and by the 8000 grit Glasstone it whittles hair to extremely thin curls. My new 16000 grit Glasstone gets it to a level where it severs hair in two when you just touch the hair to the knife sometimes, and by .05 microns on the lapping film it is just an overkill edge. M4 reaches sharpness milestones like tree topping and hair whittling usually 1 grit sooner than ZDP 189, so for me it is the steel I get the sharpest, though ZDP isn't bad.

My angles on my ZDP Steetch 2 are 7 per side with a 10 per side microbevel and it works fine. You might try using your Edge Pro to set the micro, as hard steels like ZDP have occasionally chipped on the ceramic stones I have.

Mike

[Fred S]

I do ZDP on my Lansky diamonds all the way down as fine as I have, then I use the ultra fine white from my standard set. Strop on old leather belt with red rouge. Treetops hair every time. Stropping has to be done with some care, go slow and easy and lots of strokes. I really need an intermediate compound on a strop, to get the full polished edge on the ZDP you have to strop for ~10 minutes, stroke every 3-5 sec.

Need to pay attention, there is not much of a burr when using the stones.

[gaj999]

Thanks guys. I'll try being more patient, it's not one of my strong points.

Gordon

[gull wing]

I admire you who can feehand sharpen.
I just use an Edge Pro to profile and Sharpmaker to refine edge.

[MountainManJim]

From what I have read, using low sharpening angles for a high chromium steel like ZDP can lead to breakout of carbonates which would look like micro-chips.

I use the standard SharpMaker angles of 30/40 deg. for ZDP and can get it very sharp using the stones brown through ultra fine. I think the ultra fine stones work well for removing the tough burr that can form. But, the ZDP does not appear to end up with a edge that is as smooth or fine as say an AUS-8. I envision (though haven't verified) that the ZDP edge would look more like a sharpend concrete block; strong, but a little rough and brittle.

Just my 2 cents,

Jim

[gunmike1]

IMO ZDP gets sharpest on diamonds or high quality waterstones like Shapton Glasstones. I have had troubles with intermittent microchipping from the stones. My Stretch 2 ZDP gets extremely sharp at 7 degrees per side on my waterstones, so I know it wasn't the steel's fault when it microchips on the ceramics. With a very thin backbevel like 10 per side or less you can get very good edges on a 15 per side microbevel on ceramics using very light pressure, but I get ham fisted sometimes and cause microchipping. With my Shaptons I never have edge problems with my ZDP. I also get next to no burring with my waterstones where the ceramics can raise a tiny burr with a tad too much pressure. For most steel the ceramics are wonderful, but for very hard steels like ZDP-189 the cleaner cutting of my waterstones works better.

Mike

[Scottie3000]

Here's a question for the more experienced sharpeners like GunMike or maybe Mastiff. How do you know for example you are getting 7 degrees per side with a 10 degree microbevel? Do you just know what that looks and feels like from experience or do you use some sort of guide?

[gunmike1]

I prop my stones up to the angle I want, verify it with an inclinometer ($10 or so at Lowe's), then hold my knife perpendicular to the counter I'm sharpening on. The same concept as the Sharpmaker but tilted 90 degrees.

Mike

[gaj999]

I did a little Zen stropping today and things are much improved on the sharpness front. I'll take it back down to 10 degrees a side later this week when I have more time.

Thanks, Gordon

[The Mastiff]

Scottie, I don't believe I'm at Mike's level yet. I have freehand sharpened for over 30 years. I go by the feel of the edge, it's performance, past experience with that steel, etc. I don't measure usually, and typically stop at the highest, at 8,000 grit, with a diamond strop on leather.

Some steels I may not take near 8,000 grit. ZDP is one I do, along with what I'd guess to be about a 17 to 23% angle. The only steels I really will take to more extremes are M2/M4, or some of the blue steels ( Aogami).

There are times I might stop at 2,000 or under ( 800 grit sometimes)with a 40 degree inclusive angle. These are typically the wrought steels with bigger grains like D2, 440C, etc.

S90V I've found I don't really need to take it as low angled, or high grit as ZDP and it will still cut like heck. S30V is similar in the way I sharpen it.

Out of all the steels I like M2/M4 best for the sharpness I can get so very easily. Really sharp with the strop.

For wrought steels I like o-1, Vascowear, and the W series steels. Wrought stainless? VG10 is about as good as they get. That's one I like to polish up for a stainless. 4-6,000 or less grit is great for it, with no need to go higher.

[DJ]

Thanks for starting this thread .......... dj
Very informative :) ......... I have an edge pro, but have yet to sharpen ZDP ,
I usually sharpen all my knives on the same mark (top blue) I believe on the pro , its 27 degrees. Call me lazy but I dont like moveing it around. Granted my angles vary with the blade grind of the knife , but I dont care and Iam lazy :D
My turn to ask a question .........when you say 10 degrees is that like saying twenty (ten per side) ?? The blue mark on the edge pro is suppose to be 27 degrees .........so would that be like 13 degrees per side ??
Or am I lost here on this ........thanks dj

[The Mastiff]

When I say it's somewhere between 17 and twenty three degrees, yes, That's inclusive. 8.5 to 11.5 degrees per side.

As far as the edge pro, I can only guess. I've never had one. Hopefully someone else will confirm it but you do sound correct.

I do have a Spyderco sharpener and have tried it a few times. For me, I have to develop the muscle memory and learn it with enough practice as I did the free hand process, which is actually harder I suppose.

Most steels do their best between 35 and 45 degrees. When we talk about such low angles, be aware that's for very light use, and steels like ZDP, and CPM M4, which can take it.

Put a 17 degree angle on some wrought 440C ( not powder steel like S30V, ZDP, etc.), and it will self destruct on easy tasks. It was unheard of to go that low outside of specialized chefs knives, and straight razors a decade ago. The newer steels and processess have really changed things. Most of my utility knives stay around 35 to 40 degrees though. It wouldn't make sense to put a straight razors edge on a hard use knife like a manix.

[gaj999]

My turn to ask a question .........when you say 10 degrees is that like saying twenty (ten per side) ?? The blue mark on the edge pro is suppose to be 27 degrees .........so would that be like 13 degrees per side ??
Or am I lost here on this ........thanks dj

For the Mules, I set the Edgepro at about 13 degrees, below the red notch and above the black. I then sharpen with the flat of the blade down on the table of the EP. I figure that the blade itself is 6-7 degrees inclusive. 13 less half of six gives me about 10 degrees per side, or 20 degrees inclusive for the angle of the actual edge.

The blue mark gives you 27 degrees per side, or 54 degrees inclusive.

Gordon

[gunmike1]

I take most of my steels to a thin backbevel, like 10 per side (20 inclusive), then microbevel at 30-40 inclusive to give the edge strength. As Mastiff said only a very few steels can hold a 20 degree or less inclusive edge without blowing out with microchips, so microbeveling will be your freind. With microbevels you get a thin backbevel for increased cutting ability and very fast sharpening by using an elevated angle, as you are only working a tiny amount of steel.

Mike

[Mr Blonde]

I'm no sharpening fiend, but I know my way around the Sharpmaker and ZDP steel. I too have found that ZDP189 can be finnicky steel. I'm very happy with my diamond rods. If it gets too frustrating, I find that a fresh start with a few strokes on the diamond rods (and then the rest all the way up to the UF stones) really helps.

Wouter

[Toast]

Mine responds best to an inexpensive diamond rod by Smiths followed by a Sapphire Stone by lansky. ZDP-189 also seems to respond better after it has been sharpened several times.

[Joshua J.]

I've sharpened up my mules. I sharpened them all at 10 degrees/side. 52100 easily tree tops, M4 tree tops, and the ZDP won't, no matter what I do. It does shave easily.

I've sharpened the ZDP three times on my EdgePro. I'm careful to raise a burr all the way across on both sides and then take it down through the grits to 600 and then I strop. The edge on the ZDP looked like it had some micro chips through a 20X magnification so I put a 15 degree/side micro bevel on with a Sharpmaker. It helped a bit, but it's still kind of dull.

Am I doing something wrong, or is this normal for ZDP?

Thanks, Gordon

If 600 grit is the finest you go before stropping, that might be what's holding the steel back. ZDP is probably too wear resistant to finish the edge with just a strop.
I think an ultra fine stone would fix the situation pretty quick.

For a while stropping was regular procedure, but eventually I settled for the "micro-toothy" edge that you get straight off the UF stone. It seems to bite a little better, and definitely cuts my skin easier.
I sharpen my ZDP Caly 3 at around ten degrees per side with the edge set at .004" thick. The great thing about the ultra thin edge is it still cuts like crazy long after it's stopped shaving.

[tap]

ZDP-189 does NOT bend. It does not burr in the traditional (floppy edge) knife sense. It may feel like a burr and it may look like a burr until you look at it with some magnification. You will see that the "burr" is already broken /fractured at the base along way from the edge. When reprofiling it is impossible to avoid fracturing/"burring" the edge, but you are a long ways from being sharp at that point with ZDP. I don't take it to stropping levels. Most of the time I will only touch up the microbevel using a few very light strokes. So for anything other than reprofiling you do not want to use much pressure. Avoid anything that resembles a "burr" because you are just doing damage.