Do i have a heat treat issue?

[MountainManJim]

Thanks Cliff for the explanation. I was focusing my thoughts simply on the hardness and not grain sizes, etc.

Jim

[Cliff Stamp]

Yeah, you can definitely get a knife sharp, even if it is softer than expected, it just may be a bit more difficult to handle the burr as it tends to be more persistent as the steel is softer.

Note that many well known knifemakers like softer hardness levels on their personal knives, Fisk being the most well known advocate of a lower hardness level for his personal blades as he runs them around 54 HRC.

As with everything, there is always a balance of what you gain vs what you lose. Fisk argues that he gets a more aggressive cutting edge at 54 HRC after sharpening than he would at 60 HRC.

[mattman]

Fisk argues that he gets a more aggressive cutting edge at 54 HRC after sharpening than he would at 60 HRC.

{raises hand} Does this also mean that he prefers a "toothier" edge?

[Fred Sanford]

Cliff, it's been a while since I've seen you post. Nice to see ya my man. I always thought you had good information.

[Cliff Stamp]

Yes, he generally uses a fine india stone.

[JNewell]

I think this was the cause of a lot of the complaints about 440V. (?)

That is the problem, this will be exaggerated on knives with a higher carbide volume and especially the ones with the higher vanadium content because those carbides are actually harder than most sharpening abrasives. You absolutely have to get rid of the burr before you move to finer stones, if you don't then it persists and what can happen is does get removed by the finer stones it can leave patches of the edge where it cracked off which are much rougher than the finer abrasive.

1) The simplest way is to take a piece of fairly abrasive wood and do a simple draw cut across the grain, usually 1-3 strokes is enough to remove the burr as you are just scraping it off. This will dull the edge slightly but not so much that the finer abrasive will have so much work to do.

2) Grind it off, to do this :

-make sure your stones are very clean
-elevate the edge angle (a lot 5-10 degrees)
-go extremely light
-alternate passes

To make life easier on your self, before you sharpen make 1-2 passes right into a moderate stone, say 1000 grit waterstone (medium sharpmaker rods, etc.) this will grind off all the weakened metal on the edge and leave you fresh and strong metal to form an edge, this will drastically reduce burr formation during sharpening.

Sharp wit, sharp advice below!

No worries, bottom line, don't stress about it, while there is a benefit always to having the highest sharpness you can, it isn't functional if it is aggravating you. Step back, use the knife for awhile and then try again later. It isn't like it isn't going to work if it slightly less than optimally sharp. Everyone also has off days, when something isn't going right one of the things I like to do is take a knife which is very easy to sharpen, sharpen that, and then go back to the problematic one with a fresh and positive approach. Yeah it seems all new-age and power of positive thought, etc. but bottom line if you are thinking something is going to be a problem it usually will be.

Sal, Sean, thanks.

[Cliff Stamp]

I think this was the cause of a lot of the complaints about 440V. (?)

Yes 440V/S60V was difficult to harden as it required a very high austenization temperature. If you could not achieve this (it is very demanding on the ovens) then you don't put enough of the primary (melt) carbides into solution and thus the carbon content is fairly low and the resulting hardness after tempering is mid-fifties.

People were noticing the persistence of a very difficult to remove burr and that the edge would roll/dent easier than the common 60/61 ATS-34 type steels. Of course 440V/S60V, even with the lower hardness still had a greater wear resistance than ATS-34 but those two issues often put people off from the steel and they never got to where they could appreciate the wear resistance.

[Evil D]

That is the problem, this will be exaggerated on knives with a higher carbide volume and especially the ones with the higher vanadium content because those carbides are actually harder than most sharpening abrasives. You absolutely have to get rid of the burr before you move to finer stones, if you don't then it persists and what can happen is does get removed by the finer stones it can leave patches of the edge where it cracked off which are much rougher than the finer abrasive.

1) The simplest way is to take a piece of fairly abrasive wood and do a simple draw cut across the grain, usually 1-3 strokes is enough to remove the burr as you are just scraping it off. This will dull the edge slightly but not so much that the finer abrasive will have so much work to do.

2) Grind it off, to do this :

-make sure your stones are very clean
-elevate the edge angle (a lot 5-10 degrees)
-go extremely light
-alternate passes

To make life easier on your self, before you sharpen make 1-2 passes right into a moderate stone, say 1000 grit waterstone (medium sharpmaker rods, etc.) this will grind off all the weakened metal on the edge and leave you fresh and strong metal to form an edge, this will drastically reduce burr formation during sharpening.

Cliff this post has been very helpful..thank you very much. The local knife shop has Lansky clamps by themselves for $7.50 so i picked one up and i'm back in business. I started out like you said and made a few passes straight into my 1000 grit stone (which made me cringe lol). Then i went to my fine diamond stone and made super light passes just enough so the edge didn't have any shine under light. At this point i couldn't feel any burr...perhaps i've been too aggressive with my strokes in the past.

From there i skipped the Arkansas stone altogether and went straight to the 1000 grit stone making alternating passes. It's now sharp enough to push cut newsprint again, so all is well. To top it off, i also picked up a 2000 grit stone to see how that goes but i haven't used it yet.

My understanding of burrs was apparently wrong. I was under the impression that you WANT to make a burr, and then hone it off. I never considered that the burr might be breaking off and leaving the edge jagged. I'm willing to bet this is 98% of the problem when people have issues sharpening ZDP-189.

[Cliff Stamp]

I was under the impression that you WANT to make a burr, and then hone it off.

The formation of a burr is just a guide, it tells you that you have sharpened past the edge. It is more of a technique that is very useful when you start sharpening and become less and less useful later on. Similar to using a marker to outline an edge to check the angle, at some point you will be able to tell by feel if this is happening or not.

Glad it worked out, and yes, this is a common problem with high carbide steels.

[Ankerson]

Cliff this post has been very helpful..thank you very much. The local knife shop has Lansky clamps by themselves for $7.50 so i picked one up and i'm back in business. I started out like you said and made a few passes straight into my 1000 grit stone (which made me cringe lol). Then i went to my fine diamond stone and made super light passes just enough so the edge didn't have any shine under light. At this point i couldn't feel any burr...perhaps i've been too aggressive with my strokes in the past.

From there i skipped the Arkansas stone altogether and went straight to the 1000 grit stone making alternating passes. It's now sharp enough to push cut newsprint again, so all is well. To top it off, i also picked up a 2000 grit stone to see how that goes but i haven't used it yet.

My understanding of burrs was apparently wrong. I was under the impression that you WANT to make a burr, and then hone it off. I never considered that the burr might be breaking off and leaving the edge jagged. I'm willing to bet this is 98% of the problem when people have issues sharpening ZDP-189.

Usually when one is putting on a new edge then yes forming a bur is important, same with repairing ect.

Just general sharpening, touching up ect forming the bur isn't really needed.

[Evil D]

Always learning :D

[dbcad]

Very informative thread :) I'm going to reread this a time or 2 :)