General sharpening question: grit progression & ZDP

noseoil · #1

I've been chasing around an edge on my Delica (ZDP-189) for a few days now, and have a question for anyone who's interested in answering a nimrod's basic question on grit progression.

I bought a Gatco diamond kit and it works well enough, but there's a LARGE gap in reality here with respect to their selection of cutting stones. The diamonds work well enough to remove metal, but it ends there. Their "fine" diamond is a rough cut compared to my DMT diamond steels. The "ultra fine" white stone, which comes with their kit, is about a 1200 grit, much too high for the fine diamond to progress to in transition. It's like trying to polish a brick with a sheet of glass after using the fine diamond.

While I like their fixture for angle selection, I don't care for their choice of grits for the ZDP at all. It simply doesn't work properly for an edge, as the leap to the ultra fine is way too much. I'm thinking of getting a few more natural stones to fill in the gaps between the fine diamond (maybe a 250 if I had to guess) and their 1200 "ultra fine" white stone.

If I go from 220 to 320 to 600 and then the 1200 for a finish edge would this be sufficient for the ZDP with natural stones? I don't want a polished edge to use as a reading lamp, just a good, durable, sharp edge which can be touched up from time to time with minimal trouble and fuss.

Here's the clamping setup I use. There's a "C" clamp which holds the wooden block clamp to the table's edge, so changing from one side to the other is simple and secure. Just a 1/2 turn on the block clamp to loosen and tighten is all that's needed.

Thanks in advance for your replies.

Evil D · #2

As long as you're not trying to polish the bevel, I don't see why you can't get by with that. In fact sometimes I leave my edge at about 400 grit, and then take my 16k stone and lightly micro bevel it. To me this just refines the teeth that are left by the course grit, while still leaving it somewhat toothy. If you're polishing, then a tighter sequence of grit is important, but for a user edge there's nothing wrong with your setup as long as you're getting the edge sharp enough to your liking.

noseoil · #3

David, thanks for the quick reply to my question. I could get by with the "fine" diamond, but it just doesn't do this steel justice. I'm thinking I can use what I have now as a point of departure (19d for the basic profile), clean it up a bit with the 220, 320, 600 and then do a micro-bevel of about 0.020" for the cutting edge at 22-25d and 600. If I want to get really anal I can always take things to 1200 on the whole thing, but at 600 I should have a nice cutting edge which stays sharp and is "relatively" easy to maintain.

I still can't get over how hard this steel is, simply amazing. I've been out of touch with the leaps and bounds made in the industry since the 80's. Just call me Rip Van Winkle, I guess. **** getting old.

Evil D · #4

Think of it this way...people who swear by strops typically stop using stones somewhere in the 1k area, and step all the way up to a polishing compound that is 100k+.

Cliff Stamp · #5

The grit progression should not be an issue as long as you do two things :

-micro-bevel with the finer ceramic

-artificially reduce the scratch pattern on the last diamond

As you have a decently fine gradient on the system just move up one step when you switch to the fine ceramic which will put you polishing the very apex. This will then happen extremely fast even though the grit change is large because of the extreme high pressures when working on such a small contact area. As you will be working on the apex you will see changes very fast so only a few passes are going to produce obvious results.

In regards to the scratch pattern note that the depth of the scratches is not set simply by the abrasive size but by how deep each abrasive cuts into the media and you can easily reduce this by :

-vastly reducing the force applied
-use a small amount of lubricant

Combining these you can easily cut the scratch pattern depth in half.

chuck_roxas45 · #6

noseoil wrote:David, thanks for the quick reply to my question. I could get by with the "fine" diamond, but it just doesn't do this steel justice. I'm thinking I can use what I have now as a point of departure (19d for the basic profile), clean it up a bit with the 220, 320, 600 and then do a micro-bevel of about 0.020" for the cutting edge at 22-25d and 600. If I want to get really anal I can always take things to 1200 on the whole thing, but at 600 I should have a nice cutting edge which stays sharp and is "relatively" easy to maintain.

I still can't get over how hard this steel is, simply amazing. I've been out of touch with the leaps and bounds made in the industry since the 80's. Just call me Rip Van Winkle, I guess. **** getting old.

I don't really understand what you mean by that. My ZDP Endura is at 22° inclusive and finished with a 600 grit Silicon Carbide stone. It's really aggresssive. I plan to touch it up at the 30° setting on the sharpmaker with just the brown rods. That finish absolutely does great justice to the hard, wear resistant steel.

It's been at that bevel angle and finish for some time now although I have just refreshed the bevel because I just happened to sharpen it up on the 40° setting after getting it dull cutting up a lot of boxes. I was in a hurry so I used the 40° setting. I can tell you, it keeps that edge for a long time at that angle and finish.

Now, OTOH, you really aren't doing ZDP any justice by not taking the bevel angle down.

noseoil · #7

If you look at the image I posted, the setting showing 19 degrees is the angle where the stone takes a flat cut across the surface, from the cutting edge to shoulder. This was as close as I could come to the factory setting, as I didn't want to change from their geometry on the first attempt at sharpening this steel. Does this mean I'm sharpening the included angle of the blade at 38 degrees? If so, I apologize for my error in semantics. As I've said, I'm new to this stuff, so please bear with me on the terminology.

Is the edge you have shown in the picture sharpened at about 19 degrees on the sharpener I have shown, netting about 38 degrees (19 per side? Confused as usual, tim

chuck_roxas45 · #8

Most clamped sharpeners of that ilk are at degrees per side. From how it looks, it is probably degrees per side. The actual angle of contact between the stone and the knife also varies depending on the width of the blade.

The edge I showed will probably be around 11 degrees on your setup. Well, more or less...

As a beginning sharpener don't worry too much about angles and finish. I'd say focus on getting a well formed apex. Sharpness really depends on how well your apex is formed. Just think of sharpening as forming a good apex.

noseoil · #9

To correct my former post(s), the angle I have on the blade now is about 38 degrees, inclusive, or 19 degrees per side as shown on the sharpener I use. I have a lot to learn about this stuff, so thanks for your patience & the help. tim

BeLurkin · #10

Get you an edge pro with diamond blades and a set of choseras. The just touch up with the sharpmaker. Best setup I have found to date by far!

chuck_roxas45 · #11

noseoil wrote:To correct my former post(s), the angle I have on the blade now is about 38 degrees, inclusive, or 19 degrees per side as shown on the sharpener I use. I have a lot to learn about this stuff, so thanks for your patience & the help. tim

I learned how to sharpen from the forums, I'm happy to be able to.pay it forward. I'll be glad to try to answer anymore questions you have. :)

arjay18 · #12

No need to spend a ton on diamond stones and choseras. Just get the basic edge pro, some SIC moldmater stones from congress tools and they will chew thru ZDP and other super steels like nothing. Cheap and easy solution. :)

chuck_roxas45 · #13

arjay18 wrote:No need to spend a ton on diamond stones and choseras. Just get the basic edge pro, some SIC moldmater stones from congress tools and they will chew thru ZDP and other super steels like nothing. Cheap and easy solution. :)

Agreed.

Donut · #14

Make sure you are keeping your angle consistent. I imagine you start with gravity holding the guide bar against the bottom of hole the guide bar is going through.

Make sure you stay on the same spot as much as you can.

noseoil · #15

I keep reading about the different stones & systems online for sharpening. I'm wondering if anyone knows where to buy the Gatco stone holders, just the bodies without stones attached, to do my own assortment of different types of stones. Seems like the logical way to proceed, once I get the hang of things and learn more about it. There's so much available out there to work with, it seems like there should be a source for this type of holder somewhere. thanks, tim

Bill1170 · #16

Tim,

First I want to compliment you on your choice of username. Nose oil is nature's gift to the mechanically inclined, and you honor this miracle substance by carrying its name; wear it proudly!

I agree that silicon carbide stones offer great bang for the buck. Although I don't use guided systems to sharpen knives, I like SiC stones for rapid reprofiling and the aggressive edge they produce.

Bill