You got your Ceramic Mule. How you gonna sharpen it?

[Bolster]

Ok, here's some anecdotal info on the material...

Thanks for this great report with photos!

Some have opined a ceramic edge may be smooth and not toothy, but your photos show plenty of tooth. It's almost like the 3-finger test just doesn't work on ceramic (?)

[bbturbodad]

I sharpened mine last night using Venev 800 and 1200 grit stones and stropped 1 and .25 micron cbn on basswood . I spent about 15-20 mins matching the factory angle and while not nearly as sharp as I can get steel, it's much better than it was out of the box. It now bites into my fingernail, cleanly cuts paper, and will grab free standing arm hair but can't tree top it.

I've had a set of Rhaven knives that the family use in the kitchen since the original thread popped up here so I have experience with this material. I've never been able to get it as sharp as steel but the "working edge" I get on it lasts a long while and holds up to non-knife people abuse i.e. cutting on ceramic plates, sitting in the sink wet, etc.

[burlyspyder]

Ok, I decided to give it another go on manual sharpening this material. After the first session, I think I did not change my technique enough and was likely applying too much pressure in general. So today's plan was to do a 16k (1um) stropping on how I left the Rahven, and check under the scope, just to see what it might look like. Then start low again and work my way up from 1200-4000-8000, then re-strop on the microfiber block loaded w/16k.

Spoiler alert - I got set-back at each grit change, essentially back to baseline. So, somewhat rookie mistake here, but my 4k and 8k diamond plates were new, and they cut far too aggressively before being broken in, despite the super light pressure used. I did, however, get some positive feedback on the 3-finger test (indicated in each pic either + or -), which, unfortunately didn't necessarily translate into smoother cuts on paper tests. The knife was always able to push-cut paper, just varied in smoothness.

First, the 1200 worn stone probably had the best overall results. It will be interesting to see how the other plates do once they wear in.
Round1 - 1200k (well worn from previous session):

Set back after trying to progress to the 4k plate.
Round 2 - 4k (new):

Again, set back a bit, but you can see progression in both the preceding 4k series, and this 8k series.
Round 3 - 8k (new):

So initially the stropping seemed to decrease the sharpness, maybe due to the give of the microfiber, allowing it to curl over a bit on the apex, the pics seem to indicate this.
Round 4 - 16k stropping (new block and media):

I went much lighter and decreased my angle a bit, and I got it back up to 3ft+ grippy.
Round 4-2 16k stropping to 3ft+, +bonus pic:

I am starting to think a very high grit, somewhat worn diamond abrasive may be the way to go, start to finish. By hand it will take a very long time, so might need to try some belts in the shop.

Also, for giggles, I tried to see if I could use my hardest waterstones to do anything, maybe polish, or rid myself of some of the toothiness. As expected, absolutely not. Don't even bother.

I might add some additional commentary to this or just do another round of testing, but either way, more to come! The edge on this material isn't just a ghost, it's ethereal. I need to find a proton pack to get this thing honed in...

-burly

[Bolster]

Great report Burly!! Thanx for the photos!

[kennbr34]

Also, for giggles, I tried to see if I could use my hardest waterstones to do anything, maybe polish, or rid myself of some of the toothiness. As expected, absolutely not. Don't even bother.

I got a nice mirror polish from my Shapton Kuromaku 2k. It seemed to get a lot of the micro-chipping out as well, but after a certain point it just kinda stops doing anything to it.

I tried for I don't know how long to coax a decent edge out of it with a 9 micron DMT hone. Tried super light pressure, edge-trailing only, etc. Best I could get it to was 200 BESS and too smooth to really pass a 3-finger test.

I'm over this one. If it's this much of a pain to get it decently sharp, it's not worth it to me. I figured that the real challenge would be on actually abrading the material, but it just doesn't work like steel, and I am not really keen on learning to sharpen it. I've just decided to resell it.

Anyone know anything about those Sandrin tungsten carbide blades? Is that material like this, or similar to steel? I kind of figure the "tungsten' bit implies metal lol

[captnvegtble]

Success!

Below are my limited observations and experience taking a first stab at sharpening this HIC Mule...

1st: Don't try to sharpen by hand
2nd: Use a belt sander with a very fine grit and hard carbides and/or diamond stropping paste
3rd: Go slow and have patience

I started by using my 1x30 mini bench top belt sander with a 800 grit aluminum oxide sanding belt. I didn't see much effect with using the sanding belt alone, so then I applied some yellow DMT diamond stropping paste to the belt and periodically re-applied to uncovered areas as I progressed (note: make sure you get paste all the way to the edges of the belt). Using the flat steel back-plate on the sander, I alternated taking slow passes (couple times per side) using very light pressure and my thumb to stabilize the blade to prevent chattering. I found this to be very effective to even and smooth out the factory grind lines (which came irregular and a bit wavy). Full disclosure... I hand sharpen ALL my blades on bench stones, so using an electric belt sander was a bit of a new experience for me, so it took me 5-10 minutes to get my technique consistent and find the right bevel angle. I also found that moving the blade ABOVE the flat back-plate, decreasing the angle of the blade, and allowing the sanding belt to slightly curve around the bevel as I made passes (much like a strop), really helped to refine the edge.

I spent about 30-40 minutes take slow, light passes (not much pressure, and not much heat build-up), and I have a pretty good working edge that I'm pleased with... but it's still not hair shaving sharp so I plan on spending another 20-30 minutes tomorrow with some more diamond stropping paste to see if I can get it hair shaving sharp. Given how long this takes with a belt sander, I wouldn't recommend anybody try and sharpen this mule by hand... you could spend all day.

I want to amend what I said above... contrary to what I previously said, I ended up going to my bench stones to hand-sharpen and refine the edge, and it has worked pretty well. After using the 1x30 belt sander to smooth out the factory edge, I went to my DMT 1200 mesh (9 micron), and then 4000 mesh (6 micron) Dia-Sharp bench plates, and that has worked pretty well. I found I couldn't get the same control over the edge and bevel angle with the belt sander, and the bench stones gave me better control. So, hand sharpening still works pretty well with the right equipment (I used very fine mesh diamond bench stones).

[j15w]

Also, for giggles, I tried to see if I could use my hardest waterstones to do anything, maybe polish, or rid myself of some of the toothiness. As expected, absolutely not. Don't even bother.

I got a nice mirror polish from my Shapton Kuromaku 2k. It seemed to get a lot of the micro-chipping out as well, but after a certain point it just kinda stops doing anything to it.

I tried for I don't know how long to coax a decent edge out of it with a 9 micron DMT hone. Tried super light pressure, edge-trailing only, etc. Best I could get it to was 200 BESS and too smooth to really pass a 3-finger test.

I'm over this one. If it's this much of a pain to get it decently sharp, it's not worth it to me. I figured that the real challenge would be on actually abrading the material, but it just doesn't work like steel, and I am not really keen on learning to sharpen it. I've just decided to resell it.

Anyone know anything about those Sandrin tungsten carbide blades? Is that material like this, or similar to steel? I kind of figure the "tungsten' bit implies metal lol

Bro. Spyderco couldn't even ship the knife to me that wasn't blunt. I was at least expecting something worth working on. And they expect me to do it for them?

[hollowt1pz]

Structured abrasives 3M on a 2x72. The wheel or the flat have no real world impact, it's not enough of a concavity to matter in my personal testing. May have to go to the water and 10" 1200 tormek on this one.

Will update with edge pics and later CATRA edge retention testing which I'll have next week.

[hollowt1pz]

Also, for giggles, I tried to see if I could use my hardest waterstones to do anything, maybe polish, or rid myself of some of the toothiness. As expected, absolutely not. Don't even bother.

I got a nice mirror polish from my Shapton Kuromaku 2k. It seemed to get a lot of the micro-chipping out as well, but after a certain point it just kinda stops doing anything to it.

I tried for I don't know how long to coax a decent edge out of it with a 9 micron DMT hone. Tried super light pressure, edge-trailing only, etc. Best I could get it to was 200 BESS and too smooth to really pass a 3-finger test.

I'm over this one. If it's this much of a pain to get it decently sharp, it's not worth it to me. I figured that the real challenge would be on actually abrading the material, but it just doesn't work like steel, and I am not really keen on learning to sharpen it. I've just decided to resell it.

Anyone know anything about those Sandrin tungsten carbide blades? Is that material like this, or similar to steel? I kind of figure the "tungsten' bit implies metal lol

I do. They're not like this and more similar to steel. Any other questions I may be able to please ask away as carbide grades were what I did for 27 years.

[ZrowsN1s]

So I got around to testing the edge. 232-239 BESS. Not that sharp (for me). I tried stropping through a progression of 5-.25 micron diamond paste on leather.

It made the edge worse. 297-303 BESS. Never had that happen before. Stropping always improves the edges for me. Interesting result.

[ZrowsN1s]

.... so 15 dps. Sharpened to 3000 grit diamond. Edge now measures 436BESS

I'm using a jewlers loupe. Apex is clean. So far I'm not liking this material

*edit*
.....well now thats interesting.


Terrible BESS score, won't shave hair, BUT smoothly cuts cardboard and plastic. Interesting. Shouldn't be a surprise I suppose, but definitely behaves different than steel. Not sure how to quantify the edge sharpness. BESS not a good reflection of cutting ability.

It is a good reflection of push cutting perhaps, but I think this material needs a CATRA like test or slicing test to tell the whole story.

I think shaving sharp isn't something I can achieve with my equipment.

*edit#2*
Initial sharpening done on wicked edge 15dps 1500, 2200, 3000 grit diamond. 430ish BESS.

I just did a few passes on the sharpmaker 15dps coarse diamond. 378 BESS. Seems coarser edge ups the bess score. Cutting has a little more 'bite', but I feel like it cut cardboard smoother at the higher grit/worse BESS score. Counter intuitive.

[sal]

Hi Matt,

Unexpected performance?

It's strange stuff to be sure. I found that my HIC Mule would have no problems slicing tomatoes. Though it didn't "feel" sharp enough to slice a tomato. Normally I would grab a serrated Spyderco to slice a tomato, so I was actually surprised that it worked so well. I've been sharpening it regularly with the coarse CBN rod on the Gauntlet. Perhaps it was the coarser edge on the HIC? .............................. Vivi?

Have any of you found that it performed in a way that you did not expect?

Perhaps the coarser edge affects the Bess in unexpected ways, since we always go finer and finer for a good "Bess Edge".

sal

[ZrowsN1s]

Hi Matt,

Unexpected performance?

It's strange stuff to be sure. I found that my HIC Mule would have no problems slicing tomatoes. Though it didn't "feel" sharp enough to slice a tomato. Normally I would grab a serrated Spyderco to slice a tomato, so I was actually surprised that it worked so well. I've been sharpening it regularly with the coarse CBN rod on the Gauntlet. Perhaps it was the coarser edge on the HIC? .............................. Vivi?

Have any of you found that it performed in a way that you did not expect?

Perhaps the coarser edge affects the Bess in unexpected ways, since we always go finer and finer for a good "Bess Edge".

sal

I was ready to give up on it until I started cutting up some cardboard with it. It performs at a much higher level than the edge would have me believe.

I do think that this material might do best with a coarse edge. Need to play with it some more.

[muleshaman]

Hello Spyderco fam! This is my first ever post. I've been a loooong time fan of spyderco but never really got serious into knives until a coworker recently reignited my passion for all things sharp. Anyways enough with the introduction, I got a HIC mule because I was so intrigued by the material. I have zero personal experience with ceramic so opening the box of my HIC mule and playing around with it I had zero expectations. Let me tell you I love it! It doesn't feel anything like steel when touching it with my fingers as others have mentioned, yet it cuts paper and carboard with ease. Truly an incredible material. As for sharpening, I turned to youtube . I had no idea how to sharpen this thing so I stumbled upon the Jende channel. Seeing Tom from Jende sharpening ceramic knives and then literally shaving his head and face with said ceramic knife really gave me hope! Well I sent him a email and dropped some coin on supplies. No one here has mentioned trying diamond film. That's what Tom uses to sharpen his ceramic. Diamond film on acrylic blanks, 1"x6" plates. I have a worksharp professional precision adjust that ill be using. I ordered the 45 micron, 15 micron and 9 micron diamond films and also a nanocloth strop with .5 micron max concentration poly diamond stropping emulsion. Talking with Tom from Jende he said the reason diamond on steel plates aren't producing good results is because its just too rough and chipping the micro ceramic serrations rather than aligning and refining them. Ill keep yall posted with my findings as I am very excited about trying to sharpen this mule with presumably the correct tools.

[Michael Janich]

Dear muleshaman:

Welcome to the Spyderco Forum.

Stay safe,

Mike

[burlyspyder]

Also, for giggles, I tried to see if I could use my hardest waterstones to do anything, maybe polish, or rid myself of some of the toothiness. As expected, absolutely not. Don't even bother.

I got a nice mirror polish from my Shapton Kuromaku 2k. It seemed to get a lot of the micro-chipping out as well, but after a certain point it just kinda stops doing anything to it.

Interesting - I only tried stropping on the stones given the previous advice. So, I spent an hour or so working the material on some waterstones. First, I tried 1200, and it does actually cut, but the edge becomes very chippy. Then I tried the 4k, and it started to polish reasonably well. Still pretty chippy though.

Then I thought - if the edge is so thin and brittle, we should NOT have slurry on the stones. So I left a very light stream of water on the stone as I worked on the 4k, and the results are promising, albeit slow. I am polishing out the previous grit scratches, and the cuts are getting smoother. Following the same line of thought, I can feel tiny chips/grit on the stone develop if my angle gets a bit too high or I get too close to an edge on a stroke, and they are very tiny pieces of the HIC. My hypothesis: When you go over a tiny HIC chip while sharpening, it creates new chips on the apex, leading to perpetual chipping...UNLESS, you keep the stone very clean during the process. This feels right to me.

Here is the 1200 progression:

Then, switched to 4k. Notice the polishing as it progresses. I wish I had a 2.5k stone to have something in between, but this shows that the waterstones do actually work, and the 1200 worked surprisingly well in a short time:

All that said, I am now thinking that essentially polishing this to sharpness is the way to go, similar to my previous thought of very high grit (50-100k) on a leather belt. I also strongly suspect I need a more obtuse angle at the the apex to reduce the micro-chipping. I might get into the shop today to play around some more and will post results.

-burly

[burlyspyder]

No one here has mentioned trying diamond film. That's what Tom uses to sharpen his ceramic. Diamond film on acrylic blanks, 1"x6" plates. I have a worksharp professional precision adjust that ill be using. I ordered the 45 micron, 15 micron and 9 micron diamond films and also a nanocloth strop with .5 micron max concentration poly diamond stropping emulsion.

I was using Jende nanocloth-acrylic block and 1um spray in my previous post. I also ordered 0.5um 3M diamond film a few days ago, along with some 2x8x1 aluminum blocks to use as a backings. Acrylic might be better, but I figured if the aluminum backing doesn't work, it's just material I can use for another project.

The nanocloth stropping did work to an extent, but I think it might have a little too much give, allowing the apex to micro-chip.

-burly

[hollowt1pz]

Interesting - I only tried stropping on the stones given the previous advice. So, I spent an hour or so working the material on some waterstones. First, I tried 1200, and it does actually cut, but the edge becomes very chippy. Then I tried the 4k, and it started to polish reasonably well. Still pretty chippy though.

Then I thought - if the edge is so thin and brittle, we should NOT have slurry on the stones. So I left a very light stream of water on the stone as I worked on the 4k, and the results are promising, albeit slow. I am polishing out the previous grit scratches, and the cuts are getting smoother. Following the same line of thought, I can feel tiny chips/grit on the stone develop if my angle gets a bit too high or I get too close to an edge on a stroke, and they are very tiny pieces of the HIC. My hypothesis: When you go over a tiny HIC chip while sharpening, it creates new chips on the apex, leading to perpetual chipping...UNLESS, you keep the stone very clean during the process. This feels right to me.

*placeholder for pics*

All that said, I am now thinking that essentially polishing this to sharpness is the way to go, similar to my previous thought of very high grit (50-100k) on a leather belt. I also strongly suspect I need a more obtuse angle at the the apex to reduce the micro-chipping. I might get into the shop today to play around some more and will post results.

-burly

You guys know what you are doing with materials more than any other forum I have seen. This is good news!

How many of you guys "set" your diamond abrasives? By "set", I have knowledge in applied physics and in civil engineering, so I don't know everything. I welcome any advice or knowledge that anyone has! But, "setting" (or "dressing"), is what *I* have heard about from stone cutters with MCD/CBN blades and 8" wheels. I'm honestly not sure what the end effect of it is with this material, but every person.. much smarter than I, that I have said this to does not do it, but believes that it realistically could make a difference and not just "in-my-head". I have gotten it ready for CATRA edge retention testing which I will attach all of the media involved in preparation testing and pertinent information. It took me a minute. DO NOT TRY TRIZACT BELTS unless you wanna kill said belt instantly. However, I finally finished it with 3 brand new STARCKE 1200 Al²O³ under partial flood cooling at about ~1350 SFM on, initially, a flat platen. I then towards the end swapped to the KMG rotary platen which has a rubber belt for the backing with adjustable tension. It's BESSing in the 2-220s, but will not slice a paper towel which is what I expect from this stuff. (Edit; meaning I didn't expect it to, if read incorrecrtly) HRA to Vickers hasn't been done yet for many reasons. I'm mailing it out Monday morning for CATRA testing. Tester guy lives relatively near me in the neighboring county. I'll be posting results as soon as I get them for y'all. I'm going to include as much media as possible, all of the equipment procedures for getting a proper test result, and then my final review of this release and I may opine on some of the newer sintered carbide alloys.

[hollowt1pz]

I was using Jende nanocloth-acrylic block and 1um spray in my previous post. I also ordered 0.5um 3M diamond film a few days ago, along with some 2x8x1 aluminum blocks to use as a backings. Acrylic might be better, but I figured if the aluminum backing doesn't work, it's just material I can use for another project.

The nanocloth stropping did work to an extent, but I think it might have a little too much give, allowing the apex to micro-chip.

-burly

Hey, I tried 3M 0.1

[sal]

Hi Hollowt1pz,

Looking forward to your results.

sal