Sharpening high hardness and wear resistant steels

Luong, your reply to the VC volume % in 10V was not a reply at all. Elmax and chromium carbides? Whatever man.
 
bluntcut said:
I guessed the curvature by how much light reflected back from single light source.
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I re-did the bamboo cutting test using the DMT EEF and deliberately induced a significant amount of convex to the edge bevel to increase the angle at the apex to ~17.5 degrees per side:

[video=youtube;hQXQq1-H4cM]http://www.youtube.com/watch?v=hQXQq1-H4cM[/video]

The results were as follows:

There was no noticeable difference in the initial sharpness obtained off either abrasive. Both apexes were able to cleanly and easily do crossgrain pushcuts on newsprint at all points along the apex.

There was no noticeable difference in the apex strength obtained off either abrasive. Both apexes suffered comparable amounts and extents of microscopic apex chipping after doing similar amounts of hard cutting into bamboo chopsticks.

This additional test therefore still failed to produce any evidence to support the hypothesis that any noticeable negative side effects are produced on high hardness, high vanadium content steels from being sharpened on aluminium oxide or silicon carbide abrasives.
 
^ Outstanding follow-through with a well conducted test, Steel_Drake!

I am convinced with your evidence of 1 (Spyderco Maxamet Mule) which supported your assertion. I am looking forward for one more evidence - HeavyHanded's guided tests with 10V... Then I will try to replicate at my end using various sharpening medias & styles. After that, I would like to see at least a few evidences that average sharpeners can actually produce equivalent edges on high vc steels regardless of abrasive.
 
bluntcut said:
^ Outstanding follow-through with a well conducted test, Steel_Drake!
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Thank you. A fair bit of work has gone into producing these videos.

Also, for the record, my only issue with your comment about curvature on the Spyderco M apex having caused the difference in outcomes between the initial DMT EEF test and the Spyderco M test on bamboo was that you had guessed the amount of curvature. I would have been much more comfortable if some independent program or tool had been used to estimate the difference in angle, particularly in this type of test where +/- 1 degree in edge bevel angle could have been the difference between showing similar damage to the Spyderco M test, and showing no damage at all.

I am convinced with your evidence of 1 (Spyderco Maxamet Mule) which supported your assertion. I am looking forward for one more evidence - HeavyHanded's guided tests with 10V... Then I will try to replicate at my end using various sharpening medias & styles.
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It's entirely possible that the outcome may be different on 10V than it was on Maxamet, as 10V has a fair it more vanadium than Maxamet does. I will be interested to see what results HeavyHanded gets and how those results compare to my own testing. Regardless whether they are the same, similar or different they will provide an opportunity to learn something, and ultimately that is what interests me.

After that, I would like to see at least a few evidences that average sharpeners can actually produce equivalent edges on high vc steels regardless of abrasive.
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That is one aspect that needs more investigation. My preference in waterstones is for extremely weak-bond stones that readily produce a slurry, I flatten my waterstones with an Atoma 140 immediately prior to each use, and deliberately try to raise and maintain a slurry while I am sharpening on them.

I messed around with trying to use my King 4000 without flattening it and without any slurry at all and used that way it was doing almost nothing to Maxamet. Yet the same King 4000 appeared to work fine when I used it the way I normally do. The images Jason took of the lack of results his Shapton Glass 1k produced on 10V also seem to suggest that AlOx waterstones don't work very well on high hardness, high VC steels used without a slurry, and his images of the same 10V blade off his King 1000 suggest that the King 1k worked fine on 10V with a slurry.

Another issue is that the Spyderco solid sintered alumina benchstones are quite slow to begin with, much less on these types of steels. I was saving time by using a waterstone near my Spyderco M's effective grit to do most of the grinding and then just using the Spyderco M to get a crisp apex. With the relative lack of feedback those stones provide, and their slow cutting speed, I could see a lot of sharpeners having a hard time with the Spyderco stones in extrended use.

Of course, in my actual EDC use I would just set my edge bevel angle a little lower than I wanted my apex angle, use my preferred waterstones on the edge bevel, and then switch to non-friable abrasives to set the apex with a microbevel at my desired apex angle. I've used my Spyderco M quite a bit in this role, though recently I've been more fond of a DMT EEF apex finish.
 
My video in OP used coarse low grit SiC because they can do better & faster profiling than non-renewable diamond on plate. So, with your finding, maybe it's practical - for me - to toss/dope 1500grit SiC onto a Spyderco M stone to speed up the abrading and finished up with fractured grit slurry. Most people (including me) would be happy with newsprint slicing edge. I don't care much for a couple dps convex due to slurry/mud as long as edge is less than 18dps.
A potential problem I see with sharpeners with less skills while using non-diamond/cbn grit smaller than 12um, is that in searching for faster cutting speed, they might use excessive pressure, end up with poor to bad results.

^ you wrote good disclaimer. If people asking you to teach them how to sharpen a high vc steels, would you recommend/teach them your approach or diamond/cbn? Or which one would produces higher success rate?
 
bluntcut said:
So, with your finding, maybe it's practical - for me - to toss/dope 1500grit SiC onto a Spyderco M stone to speed up the abrading and finished up with fractured grit slurry. Most people (including me) would be happy with newsprint slicing edge. I don't care much for a couple dps convex due to slurry/mud as long as edge is less than 18dps.
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Won't the SiC wear the Spyderco M since it is made of aluminum oxide?

In terms of coming up with a practical approach to quickly sharpen high hardness, high VC steels the first questions should probably be what kind of apex grit do you normally use? Are you ok with using microbevels or prefer not to use them?

A potential problem I see with sharpeners with less skills while using non-diamond/cbn grit smaller than 12um, is that in searching for faster cutting speed, they might use excessive pressure, end up with poor to bad results.
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This is a very good point. I've always preferred to use very low force when I sharpen (that is a big part of why I prefer extremely weak bonded waterstones). The Spyderco benchstones in particular are well known for producing bad results even on simple steels when used too much force.

^ you wrote good disclaimer. If people asking you to teach them how to sharpen a high vc steels, would you recommend/teach them your approach or diamond/cbn? Or which one would produces higher success rate?
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That would depend on several factors: How experienced are they at sharpening? How coarse or fine an apex finish they typically use? Do they use a burr based sharpening approach? Are they willing to learn a three step/burr minimization approach? What sharpening equipment do they have?

In general terms, for people who prefer to stick to a burr based sharpening approach and prefer to run relatively coarse apex finishes I would probably recommend diamond plates as the fastest option. This is also what I would recommend to novices since I think its much easier to start by learning a burr based approach and to shear off a burr using high angle passes rather than trying to start by learning a burr minimization sharpening approach.

I also probably wouldn't recommend using Spyderco stones for anything more that creating and touching up microbevels on these types of steels. Used for microbevels, their slow cutting speed becomes irrelevant since you're only doing 5-10 passes per side.

My advice would be different for anyone comfortable using a three step/burr minimization approach (for those not familiar, the three step approach is to cut off the old apex by drawing the knife into a sharpening stone until the apex visibly reflects light from a directed light source, shape the edge bevel until light from a directed light source no longer visibly reflects from the apex while trying NOT to raise a burr, then increase the angle and set the apex by creating a microbevel with ~5-10 passes per side), since in this case very muddy waterstones are preferred for shaping the edge bevel for their burr minimization benefits. For anyone (like myself) who uses this approach, there is no reason not to use waterstones on these types of steels since very muddy waterstones appear to work fine and any apex rounding that occurs is irrelevant since a microbevel will subsequently be applied.

My own approach is chosen based on being comfortable using a three step/burr minimizaton approach and preferring relatively fine apex finishes. Basically, I want the fastest way to get a ~4000 grit apex finish that will easily do crossgrain pushcuts on newsprint, and which I will be able to keep touched up for some time between full sharpenings. For me, I would use an SPS-II 240 to remove the previous microbevel, SPS-II 1000 to shape the edge bevel until the apex no longer reflected light from a directed light source, and then set an apex microbevel at an at least slightly higher angle using a DMT EEF or Spyderco M (or a coarse particulate abrasive loaded strop, but that's a topic for another thread). This approach will get me from cutting off the previous apex into a stone to doing crossgrain pushcuts on newsprint again in ~10 minutes.
 
Steel_Drake said:
Won't the SiC wear the Spyderco M since it is made of aluminum oxide?

In terms of coming up with a practical approach to quickly sharpen high hardness, high VC steels the first questions should probably be what kind of apex grit do you normally use? Are you ok with using microbevels or prefer not to use them?



This is a very good point. I've always preferred to use very low force when I sharpen (that is a big part of why I prefer extremely weak bonded waterstones). The Spyderco benchstones in particular are well known for producing bad results even on simple steels when used too much force.



That would depend on several factors: How experienced are they at sharpening? How coarse or fine an apex finish they typically use? Do they use a burr based sharpening approach? Are they willing to learn a three step/burr minimization approach? What sharpening equipment do they have?

In general terms, for people who prefer to stick to a burr based sharpening approach and prefer to run relatively coarse apex finishes I would probably recommend diamond plates as the fastest option. This is also what I would recommend to novices since I think its much easier to start by learning a burr based approach and to shear off a burr using high angle passes rather than trying to start by learning a burr minimization sharpening approach.

I also probably wouldn't recommend using Spyderco stones for anything more that creating and touching up microbevels on these types of steels. Used for microbevels, their slow cutting speed becomes irrelevant since you're only doing 5-10 passes per side.

My advice would be different for anyone comfortable using a three step/burr minimization approach (for those not familiar, the three step approach is to cut off the old apex by drawing the knife into a sharpening stone until the apex visibly reflects light from a directed light source, shape the edge bevel until light from a directed light source no longer visibly reflects from the apex while trying NOT to raise a burr, then increase the angle and set the apex by creating a microbevel with ~5-10 passes per side), since in this case very muddy waterstones are preferred for shaping the edge bevel for their burr minimization benefits. For anyone (like myself) who uses this approach, there is no reason not to use waterstones on these types of steels since very muddy waterstones appear to work fine and any apex rounding that occurs is irrelevant since a microbevel will subsequently be applied.

My own approach is chosen based on being comfortable using a three step/burr minimizaton approach and preferring relatively fine apex finishes. Basically, I want the fastest way to get a ~4000 grit apex finish that will easily do crossgrain pushcuts on newsprint, and which I will be able to keep touched up for some time between full sharpenings. For me, I would use an SPS-II 240 to remove the previous microbevel, SPS-II 1000 to shape the edge bevel until the apex no longer reflected light from a directed light source, and then set an apex microbevel at an at least slightly higher angle using a DMT EEF or Spyderco M (or a coarse particulate abrasive loaded strop, but that's a topic for another thread). This approach will get me from cutting off the previous apex into a stone to doing crossgrain pushcuts on newsprint again in ~10 minutes.
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Are you cliff stamp?
 


I've been playing with the Naniwa diamond stones.

These are the 800 and 3000 grits.

It's an excellent combination and leaves a great finish much higher then the grit rating.

Extremely slow dishing and wearing, may take years.

Disadvantage is that these are slow stones, they also load up.

Comes with a cleaner stone that is made out of the Naniwa traditional 220 stone but in nagura form.

Also very very expensive, $150 to $170 per stone, yikes

But I've really been enjoying the results, I'll share more information as I use them.
 
Sharpened zdp-189 on a sharpmaker using diamond->medium->fine->ultrafine. No problem doing it, just had to be very patient.
 
Well, I did have to put a handle on Luong's 10v blank to work well with the clamp - it could do it, but being in and out of two clamps and repeat positioning fairly important I went ahead and fabbed one real quick.. Functional if a bit matronly, not bad for a piece of hickory and a few aluminum rivets.

Have to double check my angle finder, am pretty sure everything else is in place.

HD didn't have any 3/8" Manila today, the testing will likely begin Monday or Tues. Will post up results/observations once I have a set to share.

101_0251_zpsqtvwnwmo.jpg


Edit to add: I can't believe how flexible this thing is at 68 RC.
 
DeadboxHero said:


I've been playing with the Naniwa diamond stones.

These are the 800 and 3000 grits.

It's an excellent combination and leaves a great finish much higher then the grit rating.

Extremely slow dishing and wearing, may take years.

Disadvantage is that these are slow stones, they also load up.

Comes with a cleaner stone that is made out of the Naniwa traditional 220 stone but in nagura form.

Also very very expensive, $150 to $170 per stone, yikes

But I've really been enjoying the results, I'll share more information as I use them.
Click to expand...

It will be all your fault if I buy these stones... 😉
 
DeadboxHero said:
I've been playing with the Naniwa diamond stones.
Click to expand...

I would love if you would start a thread about those stones. I have a whole bunch of questions I'd like to ask about them, but I don't want to divert this thread too far off topic.

keljian said:
Sharpened zdp-189 on a sharpmaker using diamond->medium->fine->ultrafine. No problem doing it, just had to be very patient.
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ZDP-189 doesn't present quite the same challenges as the steels under discussion in this thread because it basically doesn't have any vanadium in it. This mean that all the carbides in ZDP-189 are softer than the solid sintered alumina the Spyderco stones are made of. Even so, I found I could get the Spyderco benchstones to work fine on Maxamet at ~68 HRC as long as I was very patient, precise with my angle control, and used a light touch.

The issues with the Spyderco ceramic benchstones in particular is that they provide very little feedback when used freehand (and thus encourage angle slop), they are very slow (and thus encourage using excessive force), they load very quickly if not used with mineral oil, and they are hard enough to have a strong tendency to burnish rather than abrade (i.e. work by plastic deformation of the apex rather than abrasion), and that tendency is worsened by the stones being loaded and using too much force. All of these make the Spyderco benchstones tricky to use on highly wear resistant steels, but if used with care and patience they can work fine.

I still occasionally use my Sharpmaker to create apex microbevels and keep them touched up, and I haven't had any issues using my Sharpmaker in that way regardless of steel type.
 
A question in different perspective - Won't VC wear Spyderco M AlO?
Steel_Drake said:
Won't the SiC wear the Spyderco M since it is made of aluminum oxide? ...
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Those are highly radioactive - please ship them to me immediately for proper disposal ;) Cost of these is about same as JKI offering.
The 3K is close to my target finishing 2-3k regular waterstone grit. So 5K diamond stone would be an instant buy for me.
DeadboxHero said:
...I've been playing with the Naniwa diamond stones...
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Nice handle (ok, much nicer than my Young Franken) :p. HF sometime has 1/2" dia sisal rope for cheap. I think, twine 1/8" dia would works fine for these test, especially when you are sharpening between 14-15dps. Yup, as ice-pic concurred, these blades will flex like blades in common steels.
HeavyHanded said:
Well, I did have to put a handle on Luong's 10v blank to work well with the clamp - it could do it, but being in and out of two clamps and repeat positioning fairly important I went ahead and fabbed one real quick.. Functional if a bit matronly, not bad for a piece of hickory and a few aluminum rivets.
...
Edit to add: I can't believe how flexible this thing is at 68 RC.
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Thanks for followups. Since you have a WE (hence good angle control) and if you don't mind do a bit of testing between dia & non-dia finished edges. :thumbup:
Slice paper towel & newsprint -> scrape pine (as if you try to fold burr/wire over) -> slice paper towel and newsprint. Repeat with increase pressure on scrape until one type of finished edge no longer cleanly slice paper towel & newsprint.
ice-pic said:
I would like to add to this if I can.
I posted earlier (#171) that i wanted to remove those scratch path to microchip marks if I could.
I sprung for a new stone 1500 grit diamond for my wicked edge. https://goo.gl/photos/NAJaM3FhMJEJ1fzS8
...Results is no micro chips and no scratch path,and one very sharp knife.
This is all at 15deg/side.
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I would love to contribute to this wonderfull crystal weaving method.
I will do a test but I need to plan it a little.
I love the knife so much I am cringing at that blade damage,need time to get comfortable with it.
The knife is a lot different now than when I got it.I have refined the heck out of it to a fillet-paring knife and I really like it.
It is tuned for ultimate blade control in soft tissue and skinning.The feedback from carbon fiber handle to blade is perfect and
the blade is nearing a mirror finish.(hard to achieve after hardening to hrc68)
Anyhoo good news is I have gotten photo through the microscope and will post revelant ones here.
Jay
 
These tests are mostly about edge finished with various abrasives vs high rc+cv steels. Yeah, it will consumes steel in the process... and hard to fight the urge of destruction testing.

Maybe better off if/when I make a few more 68rc (avg close to 68.25rc) 10v blades. Latest ht might/could inherits a slight improvement on 1/4-1/2" blade/bevel above apex. I don't have to do this due my planned down time for a next few months. So thanks for considering but quite clear that, your 10v slicer better serves a well tuned dedicated slicer than testing.

ice-pic said:
I would love to contribute to this wonderfull crystal weaving method.
I will do a test but I need to plan it a little.
I love the knife so much I am cringing at that blade damage,need time to get comfortable with it.
The knife is a lot different now than when I got it.I have refined the heck out of it to a fillet-paring knife and I really like it.
It is tuned for ultimate blade control in soft tissue and skinning.The feedback from carbon fiber handle to blade is perfect and
the blade is nearing a mirror finish.(hard to achieve after hardening to hrc68)
Anyhoo good news is I have gotten photo through the microscope and will post revelant ones here.
Jay
Click to expand...
 
Steel_Drake said:
I'll give you guys three guesses on what I'm about to say, though you probably won't need them.

There is an obvious tool choice for this application that is being overlooked. Sigma Power Select II waterstones are made from silicon carbide with very little binder, and should have no trouble cutting any steel regardless of hardness or wear resistance.

Exhibit A:

[video=youtube;Tsj1U2bx-L8]http://www.youtube.com/watch?v=Tsj1U2bx-L8[/video]

Considering I managed to successfully apex a ceramic knife on an SPS-II 1000, I don't see why it would have trouble 10v.
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do we get the same cutting speed at 3k? also how is the finish? do these stones have the feel of the norton crystolons?
 
Thanks.

50um (~coarse hair dia) resolution shows some details - look like some micro chips (~20um x 13um WxT) but generally very clean apex. I bet this apex is sticky :thumbup:

ice-pic said:
I finally got a half decent photo,should be good enough to show the scale of my microscope on highest power.
Excuse the external links only way l know how to show hi-resolution photos.

scale
https://goo.gl/photos/B6H37cnbRpgH9Kk97

scale and blade
https://goo.gl/photos/z58rwQaSLWNKfK9k7
Click to expand...
 
Ive read through this, and im probably more than ignorant to alot of the metallurgical jargon. The knowledge you all have is staggering.

I currently have an edge pro, with the chosera set from chefknives to go. Chosera 400, 1k, 3k , 5k and 10k.

Sounds like, and correct me if im wrong, but after say the 400 grit, i need to go to cbn or diamond paste/spray to avoid burnishing or tearing out carbides. Its counterproductive to go through my usual grit progression with m4 or s110v. I dont want to spend time on unnecessary steps, or doing something that degrades my edge.

Should i put money into strops and pastes, or get dmt 2x6 to use in my edge pro.

Im profecient with the edge pro, and thought i had sharpening steel down, but i see there is another level of sharp I'd like to get to.
 
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