Is this carbide tear out, or something else?

Two parts to this reply.

PART-1
Two questions:
1) Do you begin sharpening by destressing the edge, making apex flat removing all previously sharpened (worked aka fatigued) steel)?
2) During your grit progression are you using edge-leading or edge-trailing at each stage, and do you change based on where you are in the progression)?

I have personally had a few blades where an obtuse geometry (20-25dps) was weak, where a more acute geometry (15dps) later performed well on same knife in same applications. I attributed this to what we learned during the Elmax debacle from a few years back (fatigued apex steel weakness related factory grind effecting the temper of the edge metal). Last knife specifically was an ESEE-4 where the factory secondaries (>20dps) exhibited signs of chipping, taken to 15dps still exhibited chipping, destressed entire edge then taken to 15dps (removed fair amount of steel) and edge has held well since and became a daily carry. I had almost started to believe much of the internet that was talking (1.5 - 2 years ago) about weak edges on ESEE steel even though I owned a number of other ESEE with no such issue (I am glad I did not believe what others were saying ;-)

Knife specific example from my commentary with a little hot chaga on a cool moss bed:
IMG_20210224_170211-1200Wide.jpg

From what I have seen and read in this thread, initial thoughts related to OP issue are as others have commented (Twindog, Obsessed with Edges, 3D Anvil 3D Anvil , Stockman) possibly related to stressed apex steel), or maybe something like PART-2 below ...


PART-2
However, when I re-review the OP images and look specifically at last image of OP initial Post#1, appears to show what appears to be voids in the steel behind the apex (Quote: Post#1 " it looks like there are "holes" all along my edge."). That last photo sheds similar light on the additional photos in the OP. I have experienced similar condition on a knife a few years ago that had a VG-MAX blade core. In this steel I witnessed and experienced voids or inclusions in the blade steel that were superficially small, but opened up larger in the grinding process. I will post a link to thread and photos where I discussed this.

Here is a copy/paste from the thread mentioned above describing condition/experience:
Moving through the other knives I keep getting the sense that I am chasing chipping. Chipping that was gone or not existent appears. Initially the 3.5" Pairing had huge chips in belly and few smaller chips nearing the ricasso all of a sudden now has a chip in the forward belly close to the tip (appearing right as I finished a short light series of finishing strokes). Inspection under magnification shows the edge apex was more or less intact, but there was a hole between the edge and the transition of the small secondary to primary bevel. OMG / WTF am I seeing. Additionally, it appears there is also a faint steel pattern difference in this area (faintly captured in the photos if you look closely). Hmmm , ... blade steel inclusion???
Two photo-composites below of DM0700 3.5-Pairing (before & after):
DM0700 3.5-Pairing Composite-1.jpg
Link: https://www.dropbox.com/s/bhz3f36aegkf3v0/DM0700 3.5-Pairing Composite-1.jpg?dl=0
Shun Inclusions.jpg
Above Photo: (3 photo composite same knife, black sharpie marks inclusions, 3rd photo shows edge was intact below inclusion)

Link to thread mentioned: (Dropbox photo links from thread still active)
Shun VG-MAX Blade-Steel Inclusions ??

EDIT:
Blade Steel Composition Comparison:
Screenshot_20220712-135104~2.png

If you want to discuss PART-2, please read through the linked thread and view the images related to the situ of that thread for explanations related to the photos and the experience ;-)
 
Last edited:
Spey said:
Two parts to this reply.

PART-1
Two questions:
1) Do you begin sharpening by destressing the edge, making apex flat removing all previously sharpened (worked aka fatigued) steel)?
2) During your grit progression are you using edge-leading or edge-trailing at each stage, and do you change based on where you are in the progression)?

I have personally had a few blades where an obtuse geometry (20-25dps) was weak, where a more acute geometry (15dps) later performed well on same knife in same applications. I attributed this to what we learned during the Elmax debacle from a few years back (fatigued apex steel weakness related factory grind effecting the temper of the edge metal). Last knife specifically was an ESEE-4 where the factory secondaries (>20dps) exhibited signs of chipping, taken to 15dps still exhibited chipping, destressed entire edge then taken to 15dps (removed fair amount of steel) and edge has held well since and became a daily carry. I had almost started to believe much of the internet that was talking (1.5 - 2 years ago) about weak edges on ESEE steel even though I owned a number of other ESEE with no such issue (I am glad I did not believe what others were saying ;-)

Knife specific example from my commentary with a little hot chaga on a cool moss bed:


From what I have seen and read in this thread, initial thoughts related to OP issue are as others have commented (Twindog, Obsessed with Edges, 3D Anvil 3D Anvil , Stockman) possibly related to stressed apex steel), or maybe something like PART-2 below ...


PART-2
However, when I re-review the OP images and look specifically at last image of OP initial Post#1, appears to show what appears to be voids in the steel behind the apex (Quote: Post#1 " it looks like there are "holes" all along my edge."). That last photo sheds similar light on the additional photos in the OP. I have experienced similar condition on a knife a few years ago that had a VG-MAX blade core. In this steel I witnessed and experienced voids or inclusions in the blade steel that were superficially small, but opened up larger in the grinding process. I will post a link to thread and photos where I discussed this.

Here is a copy/paste from the thread mentioned above describing condition/experience:
Moving through the other knives I keep getting the sense that I am chasing chipping. Chipping that was gone or not existent appears. Initially the 3.5" Pairing had huge chips in belly and few smaller chips nearing the ricasso all of a sudden now has a chip in the forward belly close to the tip (appearing right as I finished a short light series of finishing strokes). Inspection under magnification shows the edge apex was more or less intact, but there was a hole between the edge and the transition of the small secondary to primary bevel. OMG / WTF am I seeing. Additionally, it appears there is also a faint steel pattern difference in this area (faintly captured in the photos if you look closely). Hmmm , ... blade steel inclusion???
Two photo-composites below of DM0700 3.5-Pairing (before & after):
DM0700 3.5-Pairing Composite-1.jpg
Link: https://www.dropbox.com/s/bhz3f36aegkf3v0/DM0700 3.5-Pairing Composite-1.jpg?dl=0

Above Photo: (3 photo composite same knife, black sharpie marks inclusions, 3rd photo shows edge was intact below inclusion)

Link to thread mentioned: (Dropbox photo links from thread still active)
Shun VG-MAX Blade-Steel Inclusions ??

If you want to discuss PART-2, please read through the linked thread and view the images related to the situ of that thread for explanations related to the photos and the experience ;-)
Click to expand...


(Note I did edit your post when quoting, to remove the images to keep the reply smaller. Sorry! Also, that moss looks absurdly fluffy!)


Now that I have done a spread of different D2 knives, the issue is only found on the QSP Penguin D2's that I have been working with, 3 of them so far - two satin and one black stonewashed. Once I ground away quite a bit of the edge steel I started to hit steel that felt... smoother? After that I progressed upwards and I stopped having so many of the edge voids, though there are still a couple. On the CRKT D2 and Civivi D2 blades I tried, both of those "feel" better while sharpening, less.... gritty? and the CRKT D2 and Civivi D2 both came out a ton smoother without all the holes. I'm probably going to chalk it up to the factory edge probably being stressed or overheated because once I get through a bit of that edge material the sharpening feels better and the results are a ton smoother. Thanks for the long detailed reply :)

Oh, to answer your initial question - on these knives, all of them fresh out of the box, I didn't flatten the edge before sharpening, I was just refining/cleaning the stock edge, but I noticed with all of the QSP's that I could see (with my eyes alone) that there were chunks of the blade edge coming off. I haven't seen that in a long time, other than when I first started using a 1x30 belt sander for sharpening and was overheating steel. I didn't see any discoloration on the QSP D2, but man did it crumble the same as when I used to overheat the heck out of things many years ago. Gosh, I do miss the 1x30 leather belt for stropping, that was such a time saver ;)

The second part, I do back and forth/sawing motions with the KME when I am doing bulk removal, then go to edge leading as I finish up with each grit, then on the higher grits just edge leading, though of course if I use polishing films or strops I do edge trailing. Usually. Definitely don't have a couple of strops that I sliced into because I was on auto pilot.
 
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Spey said:
Same. 15dps is a stepping into (beginning relationship) with blades I intend to use for cutting.
Click to expand...

Just want to check, are you guys talking 15 inclusive? Or 15 per / 30 inclusive?
I tried to do one of these QSP's at 17 inclusive and it just crumbles until I chased the edge back almost a full MM from the factory edge. Then, it's just chippy but not literally turning to what feels like gravel.
 
Clint_Beastwood said:
it adds scratches at the inner edge of the bevel
Click to expand...
what is the knife and magnification of the pic with bevel shoulder scarred up? Is this visible with just eyes n light.

As long as angle is the same, I'd say this bevel is too thin for KME's 50 grit Beast. If so, that is the stone's design, so I would not waste it by wearing "it in"... well, unless I was playing with it to define the stones utility. Use it on thicker stock and as it breaks in, clogs up, wears down, the servicabilty will change.
 
scottc3 said:
what is the knife and magnification of the pic with bevel shoulder scarred up? Is this visible with just eyes n light.

As long as angle is the same, I'd say this bevel is too thin for KME's 50 grit Beast. If so, that is the stone's design, so I would not waste it by wearing "it in"... well, unless I was playing with it to define the stones utility. Use it on thicker stock and as it breaks in, clogs up, wears down, the servicabilty will change.
Click to expand...

It's bare-eye visible as a reflective white line just behind the bevel. i started cheating, and do one pass with a bunch of pressure on the kme before i switch grits, it pushes the blade down and smooths out that back edge. It's ugly, but it cleans it up a bit. I talked to a couple other users of "the beast" and its apparently par for the course until the stone gets worn in.

After hogging out about .5mm of edge steel on the QSP Penguin, i got to "live" steel, it felt much smoother and less gritty, and here is the result, after following the same progression.
https://imgur.com/aY6tMMW

Not trying for a mirror edge there, just timing myself on each grit to make sure I do it approximately the same each time. I did switch honing oils between the first round of the QSP penguin and this attempt. I was using palmers cocoa butter oil because it smells nice and my wife was going to throw it away (and it makes my hands feel nice) and swapped to dan's honing oil just in case. I've flipped back and forth between the two oils with no noticeable change beyond the smell. TBH I prefer the palmers, it smells like cookies ;)
 
Clint_Beastwood said:
Just want to check, are you guys talking 15 inclusive? Or 15 per / 30 inclusive?
Click to expand...
Not speaking for others, but my reference of 15dps:
15dps = 15 degrees per side
15inc = 15° inclusive
15 by itself is poor writing, leading to potential misinterpretation.

In my experiences;
Typically when people are speaking about knives they are referencing degrees per side.
VS
Typically when people are speaking about axes they're talking about degrees inclusive.

I typically always include a qualifier (dps or inc) to eliminate confusion.
 
I was referencing 15dps. Definitely would not take anything short of a razor to 7.5dps.

I had a KME Beast and gave up on it after 3-4 knives. Just too harsh for my tastes. If you use it, I would *highly* recommend moving on to the next grit before you apex the blade.
 
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