Never had this happen before, help

[knivesandbooks]

So I'm working on sharpening up my 52100 manix and it keeps chipping as I go. I've been sharpening for awhile and every time I get the chips gone, they just come back. I've not had this happen on any steel before. Is it tempered poorly? Is it my fault? I started with ceramics on the sharp maker and when I wasn't getting goid results I moved to my KME with a 600 grit diamond stone. I thought perhaps the stone was too aggreasive but it was chipping on a 1200 grit as well. It's chipping before I get a burr too. This was at both the 15 degree angle I prefer and the 20 degree angle I thought I may need to do.

Any ideas? I'm slowly ruining this manix with all the sharpening.

[Bloke]

Hey Knives,

I don’t rightly know but it sounds like you may be smashing/fracturing the edge as you go, but I wonder?

It’s easy to smash the edge of something like ZDP-189 by using, say an 80grit stone and moderate pressure. A 1200grit stone with little pressure ... I don’t know! :confused:

[blueblur]

Like Bloke said, you could be using too much pressure.

It’s also possible your stones are dished and need leveling. How much use have your stones seen and when, if ever, were they flattened last? If you take a straight edge and lay it across the stone can you see any light on the other side?

[PStone]

First off, I am a novice sharpener. But I too had that same problem. I was using Norton crystolon stones. I battled for a couple hours one night with the same results you are having. I think the problem was too much pressure.

The next day I gave it another go, but using very very light pressure. I also went with a microbevel. It may not be the prettiest, but I stopped chipping my edge. So I would definitely try again, using the lightest pressure you can.

[awa54]

It almost looks like you have a wire-edge, though 52100 isn't especially prone to that in my experience...

I'd suggest cutting the apex off flat and starting fresh with light stone pressure and a full progression from coarse to finishing grit on your KME. If you do remove the apex, don't take any more metal off than is required to blunt the blade, just a few times drawing the blade from heel to tip on a diamond stone ought to do it.

52100 shouldn't be too difficult, certainly not compared to most stainless steels.

My 52100 PM2 is at 15dps, no micro-bevel, works great with this steel!

[Bill1170]

Less pressure, let the stone do the work.

[anagarika]

Less pressure, let the stone do the work.

From the image, too deep scratches, can be from diamond (new stone? Or broken in already?).
Is your 1200 DMT or other brand? Reason I ask is that I have a China DMD (read DMD) that’s rated 1000 but the scratch pattern is coarser than DMT (genuine) C at 325.
It may be also too much pressure.

Suggest do what Doc suggested, but don’t do it (removing apex) on diamond, do that on sharpmaker medium.

[zhyla]

Don’t raise a burr, you’re sharpening backwards. Grind it pushing the edge towards the sharpening media, not pulling away from it.

[Pelagic]

52100 should handle anything and everything you throw at it in sharpening without any issue. Something is up.

Is it new?

[Larry_Mott]

Like Bloke said, you could be using too much pressure.

It’s also possible your stones are dished and need leveling. How much use have your stones seen and when, if ever, were they flattened last? If you take a straight edge and lay it across the stone can you see any light on the other side?

I didn't think/know KME diamond stones was possible to get concave?

[ferider]

Don’t raise a burr, you’re sharpening backwards. Grind it pushing the edge towards the sharpening media, not pulling away from it.

This ^^^^

And, just guessing from the picture: (1) put the stone on the table (stationary), move the knife with little pressure - don't move the stone along the edge; (2) use water.

Roland.

[Evil D]

This happens if you make too much (sometimes any) burr and it's far worse with some steels than others. If you do this with ZDP you'll die of old age before you get a sharp edge unless you just cut the edge off blunt and start over. This is why I stopped using a burr as a way of knowing I'm at the apex.

[TkoK83Spy]

I always thought when sharpening freehand on a stone that you push and then pull back on the same side of the blade a few times and then do the same on the other side. So you guys are saying to only push, never to pull?

[Evil D]

I always thought when sharpening freehand on a stone that you push and then pull back on the same side of the blade a few times and then do the same on the other side. So you guys are saying to only push, never to pull?

If I'm doing some heavy stock removal to cut a new bevel I'll do both directions, or "scrubbing passes" but I always finish each grit with edge leading (into the edge) passes.

[TkoK83Spy]

Thanks David. I'll have to try this later with my Para3/M4 that I've been using a bit today.

Sharpening is freakin art. There's no one way to do it, varies with the different steels and sharpening tools. I enjoy the challenge and learning curve, including all the tips and pointers I've received here. Was working on my Centofante 3 the other day with the scrubbing passes method, gave the Sharpmaker a break because I want to be proficient in freehand as well. Oddly, I had a heck of a time getting the thing sharp in the easy going VG10 steel. Yet a couple day prior I had no problem with doing the same thing, same method with M390.

[ABX2011]

Looks like you over sharpened it and weakened the edge. By that I mean that you raised a burr and kept on sharpening at the coarse grit for an extended period and maybe with excessive pressure.

[zhyla]

I always thought when sharpening freehand on a stone that you push and then pull back on the same side of the blade a few times and then do the same on the other side. So you guys are saying to only push, never to pull?

Right, so I hesitate to say definitive things about sharpening because I’m not a metallurgist and I don’t break out a microscope to see what’s going on. But I’m just going to come out and say it.

Burrs are the devil.

Burrs are a deformation or the steel. Best case they are harmless, but it probably does bad things to the steel structure at the edge. And they are liars, making you think it’s sharp only to roll over or chip off during use.

The “raise a burr” thing he been repeated for decades. You’re going to keep hearing it repeated.

Note that even with the “push” direction you can see a burr form. I see this mostly with coarser grits. This is why people who sharpen straight razors flip the blade on each stroke. We can learn a lot from the razor people — nothing disillusions you about your sharpening job like putting a blade to your face.

[blueblur]

Like Bloke said, you could be using too much pressure.

It’s also possible your stones are dished and need leveling. How much use have your stones seen and when, if ever, were they flattened last? If you take a straight edge and lay it across the stone can you see any light on the other side?

I didn't think/know KME diamond stones was possible to get concave?

Good point. I didn’t realize he was using diamonds but saw I overlooked that bit. I mentioned it because I was experiencing similar chipping with 52100 on aluminum oxide stones that were dished. Once I flattened them I was able to get a very clean edge.

[BornIn1500]

This is why people who sharpen straight razors flip the blade on each stroke. We can learn a lot from the razor people — nothing disillusions you about your sharpening job like putting a blade to your face.

But it doesn't take much sharpening at all to put that edge back on razors, so they can afford to flip the blade every stoke. With a pocket knife, they will get way more dull before getting resharpened. It would be very time consuming to flip the blade every stroke.

[dsvirsky]

It would be very time consuming to flip the blade every stroke.

Assuming one is sharpening freehand, why would it take longer if you alternate your strokes?