ZDP-189 and Spyderco Sharpmaker

[ejames13]

Hey Everyone,

I did a search on this and didn't find much, so here goes. I'm having a real hard time sharpening my Dragonfly 2 in ZDP-189 on the Sharpmaker and I'm looking for some tips from those of you who have more experience.

I reprofiled my DF2 to ~15dps using the diamond stones on the Sharpmaker without issue. However, I can't seems to get the edge I want after I move up to the brown medium stones. On all my other knives (154CM, VG-10, S30V, M390) I'm able to get an edge that catches leg hair above the surface and push cuts newsprint at 90 degrees using the medium brown stones.

I know I'm hitting the apex on the DF2 because I'll use it until it starts to dull a little, then sharpen it back up and I can feel a difference when cutting after I sharpen it. I can get it to the point of rough shaving and cutting newsprint with a draw, but just can't seem to get it to the level of my other knives. I'm also using extremely light pressure for the last several strokes.

Furthermore, I tried what someone else suggested in another thread about adding a microbevel because then you're working with less metal, but that still produced the exact same result I was getting before.

Is it just not possible to get that hair popping edge on ZDP with the Sharpmaker? Any insight would be greatly appreciated! Thanks.

 

[DeadboxHero]

Sounds like shortcuts on the diamond hone. If you don't create a great sharp apex at the coarse level it just wastes your time refining it on the finer grits.

 

[ejames13]

Sounds like shortcuts on the diamond hone. If you don't create a great sharp apex at the coarse level it just wastes your time refining it on the finer grits.

I don't think that's the case though. I developed a burr on one side, then flipped it back and forth between sides with lighter and lighter strokes before moving from diamond to medium. Also, I did a touch up once or twice on the factory edge before reprofiling and I had the same problem.

Are you saying you're able to get ZDP hair popping on the Sharpmaker with the brown medium rods?

 

[Bob6794]

Your able to get the knife extremely sharp even on a coarse stone if you do your job, what the finer grits do is change the scratch pattern. Thus changing the cutting characteristics. A coarse grit stone will make a more toothy scratch pattern and think of it as creating micro serrations so it works better in slicing applications were it acts closer to a saw. The finer grits make a more polished or refined scratch pattern and these work better while push cutting through things, so tree topping hairs is easier off the ultra fine than the diamond even if in theory their both equally sharp due to the characteristics of the finish.

It sounds like what is going on is you may not have fully apexes the edge off the diamond stone. Use a sharpie and sharpie up your bevel and go back to the diamond stone and use that as a guide to see if your getting rid of the sharpie on the bevel, and preferably use something like a jewelers loupe to get a closer look at it to see what is going on. I find that magnifying the bevel will reveal a lot of what is going on, once I started doing that I found out that sometimes even when I thought I fully apexed a blade I really didn't because by all accounts it looked liked it and almost felt like it doing a 3 finger sticky test to feel what is going on. But upon closer inspection I found small traces of where it wasn't apexed on the blade by seeing the red sharpie I used on it. Once it's apexed going up to the higher grits will be easy.

 

[bgentry]

I've got a Delica in ZDP-189 that I previously reprofiled to somewhere in the 12 DPS range. I did it by hand on DMT diamond plates, so I don't know the angle; I just know the bevel is WAY wider than it was before and it's certainly under 15 DPS.

I just spent 10 minutes or so with my SharpMaker at the 15 DPS setting, putting a microbevel on it. I had been using the SM at 20 DPS before this, so it took a bit of work to get past the 20 DPS micro and turn it into a 15 DPS micro. Once I raised a burr on both sides and removed it, I tested it on leg hair. I have NEVER been able to treetop that I know of, though every now and then I'll get a blade that will cut a couple of hairs as I pass it over the hair over a 3 or 4 inch pass. This one didn't cut any hairs that way in either direction. <shrug>

Then I did a regular shave pass on my leg. It cut the hair very cleanly, with a little bit of pull as you'd expect from a 600 -800 grit edge. Nice clean patch of skin and a bunch of hair. I repeated this on both arms and got small clean patches with just a bit of pull. A very little bit.

I tried it on thin color ad paper that comes in the mail. It's similar to newsprint; maybe just a little thicker or a little thinner. The Delica push cuts at 90 degrees to the paper on the long edge or the short edge. This is a "big deal" because a LOT of edges will push cut one way, but not the other. Something about the direction of the fibers in the paper.

So I'd say this edge is very, very sharp. I've never treetopped, or whittled a hair so... not sure. But it shaves cleanly and push cuts thin paper.

Brian.

 

[ejames13]

I've got a Delica in ZDP-189 that I previously reprofiled to somewhere in the 12 DPS range. I did it by hand on DMT diamond plates, so I don't know the angle; I just know the bevel is WAY wider than it was before and it's certainly under 15 DPS.

I just spent 10 minutes or so with my SharpMaker at the 15 DPS setting, putting a microbevel on it. I had been using the SM at 20 DPS before this, so it took a bit of work to get past the 20 DPS micro and turn it into a 15 DPS micro. Once I raised a burr on both sides and removed it, I tested it on leg hair. I have NEVER been able to treetop that I know of, though every now and then I'll get a blade that will cut a couple of hairs as I pass it over the hair over a 3 or 4 inch pass. This one didn't cut any hairs that way in either direction. <shrug>

Then I did a regular shave pass on my leg. It cut the hair very cleanly, with a little bit of pull as you'd expect from a 600 -800 grit edge. Nice clean patch of skin and a bunch of hair. I repeated this on both arms and got small clean patches with just a bit of pull. A very little bit.

I tried it on thin color ad paper that comes in the mail. It's similar to newsprint; maybe just a little thicker or a little thinner. The Delica push cuts at 90 degrees to the paper on the long edge or the short edge. This is a "big deal" because a LOT of edges will push cut one way, but not the other. Something about the direction of the fibers in the paper.

So I'd say this edge is very, very sharp. I've never treetopped, or whittled a hair so... not sure. But it shaves cleanly and push cuts thin paper.

Brian.

Thanks very much for that detailed info. Sounds like it's definitely possible to get it a little sharper than I have been.

Two questions: 1). What method did you use to remove the burr? 2). Which stones did you finish on?

 

[bgentry]

Thanks very much for that detailed info. Sounds like it's definitely possible to get it a little sharper than I have been.

Two questions: 1). What method did you use to remove the burr? 2). Which stones did you finish on?

You're welcome. That blade needed to be touched up anyway.

1. I do something like 3 strokes on the burr side, then do back and forth strokes (one on each side) something like 10 times. Many times there will be just a bit of burr left that I can feel with my fingers (sliding away from the edge). A good method that I like, is to do one stroke at a *slightly* elevated angle. So I'll do one stroke on the burr side with the blade leaned away from the stone a few degrees. Then back and forth strokes a few times.
2. I finished on the brown/grey stones because that's what I thought you were asking about. I could probably increase the shaving a bit by going to the white stones, but I generally like the edge from the grey stones just fine.

Brian.

 

[ejames13]

You're welcome. That blade needed to be touched up anyway.

1. I do something like 3 strokes on the burr side, then do back and forth strokes (one on each side) something like 10 times. Many times there will be just a bit of burr left that I can feel with my fingers (sliding away from the edge). A good method that I like, is to do one stroke at a *slightly* elevated angle. So I'll do one stroke on the burr side with the blade leaned away from the stone a few degrees. Then back and forth strokes a few times.
2. I finished on the brown/grey stones because that's what I thought you were asking about. I could probably increase the shaving a bit by going to the white stones, but I generally like the edge from the grey stones just fine.

Brian.

Awesome, thanks again for your help! Guess I just need to keep practicing

 

[DeadboxHero]

I don't think that's the case though. I developed a burr on one side, then flipped it back and forth between sides with lighter and lighter strokes before moving from diamond to medium. Also, I did a touch up once or twice on the factory edge before reprofiling and I had the same problem.

Are you saying you're able to get ZDP hair popping on the Sharpmaker with the brown medium rods?

The steel and the abrasives doesn't change the principals of sharpening it just adds or reduces time.

In the past I find myself focusing more on progressing to higher grits more then forming a great, solid sharp apex on my coarsest stone that's burr free and then refining it to a mirror polish.

but I've sharpen many a knife and gotten too hasty and skipped steps. What resulted was a mirror edge with a rounded apex that couldn't perform.

Clean, perfect apex formation is the most important aspect of sharpening.

So you're getting burrs that's good. How about removal?
after straighten out the burr, try pulling the edge through a piece of soft wood to remove any lingering burr.
Cork and rock hard felt bricks are great.

You mentioned the brown rod, do you have the white rod as well?

The white really helps refine the edge for shaving.

Also as a final step take a piece of newspaper and lay it on something flat and hard, with the weight of the knife strop each side for a few moments.

Hope that helps.