ZDP189 steel knife. What is the best sharpening angle?

[ValeryD]

Hi all,
Just recently the knife I bought on sale arrived. This is Miyami Black, Prep knife, 140mm long. Contrary to what users of this knife write in their reviews, this knife cannot be described as sharp in any way. It is very roughly sharpened. Probably something around 800-1000grit. A dense row of sharpening scratches is clearly visible on the chamfer. The knife cuts poorly, very far from what was expected.
Now it is clear that the knife needs sharpening. On the website where such knives are sold, the description of the knife indicates that the sharpening angle is usually in the range of 9 - 12 degrees. It's pretty vague. I would like to know this angle (the best one) more accurately. Therefore, the question is: have any of you dealt with Miyabi Black knives and do you know what angle is recommended for these knives? If there are no such users, what have you heard about this?
How to sharpen and to finish when sharpening such ZDP189 steel knives?
Thanks in advance.
Valery

 

[jedy617]

Honestly, 800-1000 grit isn't the worst final grit when sharpening ZDP, it's not the best at holding a very polished edge. You could go higher, but I personally wouldn't go past 3000 grit. As for angles...that's all personal preference. There is no best angle. You could try to go as acute as possible, and if you end up chipping the knife, you will have to sharpen it and raise the angle a bit more.

ZDP can take awhile to sharpen, just keep going until you get the burr. Diamond stones are faster, but not required.

 

[pavhav]

I have a Miyabi Black Santoku that I got early in my knife exploration phase. I wanted to try out ZDP-189. I can't recall what the OTB edge was like honestly. I usually don't take it any higher than my SP2K since the carbides are so large and inherently toothy. I thinned it quite a bit as well, so I use a (fairly) conservative edge angle circa 12° since it isn't the toughest steel - I haven't had any issues with this combo.

 

[captaincaed]

Miyabi knives may have a poor factory edge, not necessarily surprising.

In my mind a good 1k edge should feel very sharp, and is pretty good for cooking. A clean 1k edge should shave a hair (it's how I set up an edge for a straight razor, and it will definitely shave). The 10-12 degree angle per side should also feel pretty sharp. Like Jedy said, if it chips too easily you can go up to 15 degrees or so.

I think one trick with ZDP is getting the edge really clean after sharpening. The coarser 1k stone can leave the edge a little "furry". Try another 10 strokes with really light pressure (weight of the knife). Then strop lightly 5-10x on cardboard (weight of the knife , same angle as sharpening). The clay in the cardboard helps deburr and clean up the "furry" edge.

Because of the high carbide content of ZDP and because all steel is ductile, sharpening creates a bit of "wire" at the edge from the push/pull of knife on stone. That's what I mean by "furry". It's weak metal that you want to clean away from the final edge. It sounds like a strange extra step, but has a big impact on final sharpness and edge durability.

An edge made like this should cut paper towel or shave arm hair. Or take the end of a finger off. Good luck!

 

[ValeryD]

captaincaed,​

How you remove the flurry residual metal (burr) at the last stage of sharpening?
On my other knives (AS and SG2) I am trying to clean the cutting edge by strokes edge leading
changing sides after each stroke. And then make several cust of a carton box walls.


Valery

 

[Dan-]

https://www.kitchenknifeforums.com/threads/kippington-deburring-video.44003/

 

[M1k3]

captaincaed,​

How you remove the flurry residual metal (burr) at the last stage of sharpening?
On my other knives (AS and SG2) I am trying to clean the cutting edge by strokes edge leading
changing sides after each stroke. And then make several cust of a carton box walls.


Valery