Community Sharpening Journal

[Doeswhateveraspidercan]

Is this the powder?

https://www.ebay.com/itm/Lapidary-Diamo ... se73PwwLnQ

What do you mix it with mineral oil?

By the way thanks to all the free hand sharpeners advice I have just purchased a Smock which I held off on due to it being S30V now with better education and tools I look forward to it.

[Pelagic]

Is this the powder?

https://www.ebay.com/itm/Lapidary-Diamo ... se73PwwLnQ

What do you mix it with mineral oil?

By the way thanks to all the free hand sharpeners advice I have just purchased a Smock which I held off on due to it being S30V now with better education and tools I look forward to it.

That's the one. I have had several of those in varying grit ratings for several years. Honestly I just add it to cheap compounds like TEMO or comparable. As much as I like sharpening I can't justify buying Ken Schwartz or Jende products all the time ON TOP of my already somewhat expensive knife hobby. I don't want to spend hundreds on super fine waterstones either. So I found a way to achieve virtually any finish on my own.

[Doeswhateveraspidercan]

Doeswhatever, the alumina abrasive particles in the Sharpmaker rods are actually the same in all of them - around 15 micron IIRC. The binder media and surface finish also have an effect on how the grit abrades and the finish it leaves.

The white F and UF rods are the same, for example, the UF rods just have a smoother finish.

The scratch pattern of the rods also becomes finer with time and use.

The Alumina particles, as I understand, used on the rods are generally 15 -20 microns. The different grits for fine and medium are attained by firing processes, not micron size. The CBN and diamonds used are 400 mesh. The ultra fines are made by tumbling the fine grits.

sal

Also there’s different types of carbides and interactions between alloy components within certain carbides. It’s not as simple as straight up Chromium, Tungsten, Molybdenum and Niobium carbides.

As far as I’m aware, the Mohs scale is not generally used for indicating specific carbide hardnesses, as it is just an ordinal scale based on what material can scratch another material.

Larrin wrote an excellent article on carbide formation in knife steels:

https://knifesteelnerds.com/2019/07/15/ ... fe-steels/

It’s great to see you heading down the rabbit hole, brother. :)

And yes, I agree: geometry and thinness behind the edge are key (along with a few other factors).

You referred to Murray Carter earlier. He’s a good teacher. A lot of his material is on Youtube.

Also The Razor Edge of Sharpening by John Juranitch basically covers the same fundamentals. I think I might have recommended it to you before.

The King stones which Murray sells tend to be optimised for sharpening simple carbon steels rather than higher carbide PM steels, but they’re good stones to have in your kit to practice with. Bear in mind, they need to be flattened regularly - they are designed to be on the softer side to continually release fresh alumina abrasive.

Yep knew that about the ceramics and how the finish determines their cutting ability. Just using a chart to try to make comparrisons. Was not my invention on the chart. Oh and Pelagic read you loud and clear will have to see what finish the 1200 Atoma produces.

I really like Murray Carter he appeals to me more than the other fellow you recommended and I want to learn from him so based on your advice concerning the stones I have chosen to start learning from him by taking the first step and buying his DVD and Stones as a package deal with shipping came to $60.00. Figure I already have the flattening equipment with the Atomas and the water table I purchased

Mr. Carter also does intensives training groups of people to sharpen I am really going to have to save up for that and would love to learn from him in person. He charges $3500.00 for that and to be honest I have spent more in technical schools over the years. here is an outline of the masters training course, looks most excellent indeed!

https://www.cartercutlery.com/knives/bl ... struction/

Thanks allot guys really appreciate all the assistance now I have to find some time to actually sharpen came home to a house needing cleaned after a pair of cats with upset stomachs pretty much made the place smell unlivable.

Oh well mops and brooms and bleach and buckets what's a fella to do?

[Doeswhateveraspidercan]

Okay so I made some time I went and dug out my old Wicked edge pro3 balsa wood strops I had loaded with their Diamond paste close to 4 years ago that I had sealed in zip lock bags.

Used the strop loaded with 3.5 Micron Diamond Paste and after about 40 passes per side and an additional ten back and forth with a light touch took my Buck110 in 440C which was a little dull and my Delice in Cruwear which I had dulled pretty good and made them telephone paper slicing machines.

Curiously the 440C was a bit toothier to smooth out but in the end is very sharp.

Guess I will be buying some lower grit diamond powder as it turns out I do have a fresh tube of 1 MIcron and .5 Micron diamond paste and a fresh balsa wood strop for the WE3 I never loaded.

Pelagic do you really think it is good to go all the way down to 1/10th of a micron? or am I reading what you wrote incorrectly? Furthermore I can see your point of going from a coarse 400 Atoma directly to the 3.0 Micron strop it does not sacrifice the toothy edge making a polished slider at all but does rejuvenate an already well apexed blade making it very sharp.

Probably no need for all the grit progressions after all. Oh well thank goodness I always pay off my credit cards after the purchase. This is an expensive hobby but a good one. Waiting to try out my new Smock great design wish I would have not been so critical of S30V in the past with these tools and the wisdom of you guys S30V doesn't stand a chance anymore.

[Pelagic]

It depends on the situation. Sharpening is like a box of chocolates and therefore intuitive.

If I reprofile on a 140 Atoma and then sharpen on a 400, I will obviously be doing my best to get the sharpest 400 grit edge possible as well as eliminate the burr (and other things). Given I'm going for my typical edge (coarse yet refined teeth), I will check how good my 400 grit edge is. In a perfect world, no stropping is necessary. But I've picked up the habit of using strops to check for burr that can't be felt or seen by the naked eye. How I feel about the edge after thumbing it and how well the edge catches or treetops my arm hairs determines what strop gets used. If it's extremely sharp, treetopping hairs, I will absolutely skip to 0.1 micron. This is for 2 reasons: I don't want to change a good thing, and diamond powder cuts so aggressively that it's better to go finer in general. If the blade is only catching hairs, I'll probably use a 3 (or possibly my 1) micron strop to test for burr, as it will bring the apex to a high sharpness faster than the 0.1 strop. After I've completely eliminated the burr (the scrape marks on the surface of the strop will tell you) I have to inspect the apex and test sharpness after nearly every pass on the strop to make sure I'm not stropping too much. I want the sharpness, but I want the teeth and cutting aggression MORE. It's very weird that there is a trade off.

You could probably blow a normal person's mind with an experiment like this:
Knife A: crisp, clean, deburred 220 grit edge. Shaves easily, can NOT whittle hair.
Knife B: 0.1 micron edge, extremely sharp, whittled hairs against AND with the grain, pushcuts newspaper 3 inches away from where you're holding it.
Geometries are equal.

You just show them 3 things and at the end ask which is sharper, knife A or knife B? After the hair whittling test and pushcutting newspaper, they'll be certain that knife B is sharper. Then if you could develop a way to put exactly 5 pounds of weight on the spine of the knife as you slice/saw through rope, the person would watch in amazement as knife A finishes the cut A LOT sooner than knife B. Like a lot of us often mention, there's sharpness and there's cutting ability. And while sharpening, you kinda always have in the back of your mind whether you want something like Knife A, something like Knife B, or something in between. On a typical day I tend to go for something in between, but much closer to knife A.

[Doeswhateveraspidercan]

I agree with in between.

Now here is a question.

We all know how great a Spyderco cuts when we get one that is sharp from the factory. Not just typical sharp but oh my God I am so in love with this I am buying a back up right now...

What would you recommend as a sharpening protocol to reproduce one of these factory fresh blades? Let’s use the standard military, PM2 or Para3 in S30V for example I have had those come in unbelievably sharp as well as many others. And they do seem to handle all tasks very well.

True most people do not have access to large belt grinders with big wheels so we use what we can in our homes.

What angle? 15 degrees?

Assuming geometry is correct what abrasive at what micron level would you recommend?

I can see fixing bevels thinning out behind the edge and apexing with something like an Atoma 140 or even the 400 which I think will be needed to refine scratch pattern and appearance after the 140.

But then what?

[Pelagic]

I think factory bevels average slightly higher than 15 degrees. 17 seems common, but so is 15 (relatively). Unfortunately I haven't seen any stone that perfectly mimics a factory edge finish. Its certainly coarse and usually deburred, which is great for EDC cutting tasks, but they aren't always extremely sharp from the factory.

[Cambertree]

I really like Murray Carter he appeals to me more than the other fellow you recommended and I want to learn from him so based on your advice concerning the stones I have chosen to start learning from him by taking the first step and buying his DVD and Stones as a package deal with shipping came to $60.00. Figure I already have the flattening equipment with the Atomas and the water table I purchased

Mr. Carter also does intensives training groups of people to sharpen I am really going to have to save up for that and would love to learn from him in person. He charges $3500.00 for that and to be honest I have spent more in technical schools over the years. here is an outline of the masters training course, looks most excellent indeed!

https://www.cartercutlery.com/knives/bl ... struction/

Thanks allot guys really appreciate all the assistance now I have to find some time to actually sharpen came home to a house needing cleaned after a pair of cats with upset stomachs pretty much made the place smell unlivable.

Oh well mops and brooms and bleach and buckets what's a fella to do?

Good stuff Doeswhatever. :)

Yeah, the whole carbide subject and how the different alloys interact in their formation, and how they influence edge qualities is a fascinating subject. It's what I'm trying to wrap my head around and get a better understanding of at the moment. I enjoyed reading your thoughts on your sharpening journey.

I'm glad you're enjoying Murray Carter's material. He's a very knowledgable guy, as you'd expect for someone who's forged over 20,000 knives.

I guess if you were to summarise one of the basic learnings that Juranitch, Carter and Sal all teach, it's to keep thinning the knife behind the edge, as well as sharpening the actual apex. Murray calls it thinning the primary grind, Juranitch calls it relief grinding, and Sal calls it back bevelling, but it's essentially the same thing.

I was lucky to spend 10 days travelling around Japan visiting bladesmiths and knife factories with Murray Carter and a few other knife enthusiasts in 2014. I learnt a lot about sharpening and other aspects of knife culture from the great discussions we had on the road, and in the evenings over meals. We visited the G.Sakai factory in Seki who make the Seki City marked Spydercos, and were guests of the Kono family who own Takefu Special steel, who make VG10 and the laminated steels Spyderco use.

Sorry, it's a little off topic, but you might enjoy some of these videos of the Carter Cutlery Japan Bladesmith tours, when you have a moment to relax. I've made a playlist here:

https://www.youtube.com/playlist?list=P ... 5XgY2ilOm5

Ok, back on topic.

Pelagic, I had a couple of questions for you.

One of the things which is quite a challenge when freehand sharpening is to get consistent angles on both sides while using the same hand. So I was quite interested in your comment about learning to use both hands. Do you have any tips on this?

Also, the discussion of using diamond powder reminded me of an experiment I read a few years ago, maybe on Cliff Stamp's forum, where someone used 220 grit valve grinding paste to basically thin out and aggressively reshape a blade to a convex profile, without using a coarse stone.

I have some 60 micron Venev diamond stropping paste I got in a sampler pack, so I was wondering how that would work on a slightly compressible substrate like balsa.

I have a S30V PM2 which has always given me trouble with tiny chips breaking out of the edge, no matter what abrasives I use, or how much I vary my pressure, angle and sharpening techniques. It's been sharpened many times. I might experiment on that and report back.

Regarding the Spyderco factory edges, Sal actually mentioned somewhere what grits they finish with. I wish I could find the quote again. Don't quote me, but I think the grind was somewhere in the 600 range, then a light buff in the 7000 range?

Again, he mentioned a while ago (back in the early 2000s) that the angles varied depending on the knife, but they are usually between 30 and 38 degrees inclusive. More recently I think I recall seeing a comment by him or Eric, that they often aim at 17.5 dps.

If I can find the actual quotes, I'll edit them in.

[Pelagic]

Yes, Cambertree, I have a tip. Start with your weak hand and end on your dominant hand. Go slow. Just allow the "muscle memory" to form over several weeks. My hands are always the steadiest in the beginning of sharpening, and this is a big reason why I try to get the job done quickly. Of course, I can always take a break and come back, but I've found that I have a higher chance of maintaining the same angle throughout the sharpening if I do it all in one sitting. I use one hand to guide the tip for stability throughout each pass (similarly to how Vivi does it on his "sharpening is simple" video using a DMT XC), and before I begin full passes, I target any extra dull spots with back and forth motions. The full passes will clean up any irregularities in the bevel.

I think there are a lot of different ways to attain desirable edges that aren't often explored. I've stropped with 30-40 micron diamond powder dry on wood as an experiment. Even the largest of burrs have no chance. And the first time I did it, my s110v military surprisingly sliced a free hanging paper towel absolutely CLEAN. The whole idea of diamond powder came about by me thinking "what separates good diamond emulsions and compounds from cheap ones?" Of course, there is the actual shape of the diamonds, the amount of variation in size of the particles, and other factors to consider, but in the end it seemed like there is a higher concentration of diamonds. So I thought "let's add more diamonds and see what happens" and the result was a game changer. I just load my 3 micron strop with Tormek PA-70 (best deal there is for stropping compound, and perfect for adding diamonds - unfortunately I believe it only comes in 3 micron) and sprinkle a bit of 3 micron diamond powder on top while the surface is still wet, and rub it in with one finger. I think I have some TEMO and "DiamondTech" or something, cheap syringes from ebay. I wasn't even willing to fork out the cash for DMT diapaste, let alone HandAmerican, Jende, Ken Schwartz, etc. Generally I always try to see if I can get a more budget friendly option to work before splurging on top shelf products, and adding diamonds to cheap compounds. Sometimes people forget that the jewelry polishing market exists with all kinds of different compounds that can be used in knife sharpening. I'd rather try 4-5 different cheap unpopular products and have a learning experience as I find out how good they are instead of just buying one product that has a good reputation. Of course if none of the cheap options work well, I'll step it up, but I tend to try them first.

Sounds like your pm2 is just one of those random s30v models that lacks apex stability. I've come.across them before from most companies who use that steel. I just stick to extra coarse edges and call it a day.

[Pelagic]

Just sharpened some benchmade folder for a coworker this morning. S30V, DLC, combo edge, automatic/spring assist. Not sure what model it was. Unfortunately all I had in my work bag was my DMT coarse and 3 micron strop again. I didn't know what to expect. The last time I sharpened Benchmade's s30v it didn't have excellent sharpening response. This one however came together nicely. Quick to form a burr, and deburred easily. I didn't have anything to sharpen the serrations, but the owner wasn't really concerned with them; he said they were good enough for his uses. Same thing as usual, back and forth passes on the bad spots, transitioning to full passes to clean up the bevel. 5 passes per side soon became 3, then, 2, then 1. It didn't take long to remove the burr, maybe 2 minutes of ultra light alternating passes. The knife owner didn't know anything about the burr and was absorbing everything I explained like a sponge. I showed him what a strop was and what they're used for. He asked what knives I like to carry and I told him spyderco is my favorite although I also carry cold steel. He was amazed at the blade treetopping hairs above the skin. I always get a kick out of that.

[Doeswhateveraspidercan]

Great discovery adding more diamond to the compound could the same thing not be achieved just using petroleum jelly?

Does the Tormec compound have diamond in it already?

[Doeswhateveraspidercan]

Oops nevermind, found it, they are using Aluminum Oxide.

https://www.tormek.com/media/1728796/pa ... _sheet.pdf

[Pelagic]

I have never experimented with petroleum jelly or oil. Something out there has to work well. The stropping compounds I use are certainly oil based but also dry up a lot sooner than i feel actual oil or vaseline would. I just see them as a means of saturating the wood or leather with diamonds, or at least getting them to stick to the surface better as opposed to using them dry. I wouldn't want the surface of the strop to remain wet for too long. I've also thought about making a spray, but my current system works fine.

Yeah, Tormek PA-70 isn't diamond, but it's cheap (for a large tube) and works effectively on any steel after diamond powder is added.

[Haunted House]

Speaking of, do you guys have a recommendation on brand of diamond spray (not paste)? All the ones I looked at seem to be 5 carats per oz.
Are they all mostly the same? Amazon has some from sharpeningdepot, CKTG carries a brand called Richmond(that advertises a “non-clumping formula”), then there’s GRS Tools brand which is twice as expensive. Hand America, wicked edge, rio grande etc.

Any recommendations?

[jpm2]

I have a S30V PM2 which has always given me trouble with tiny chips breaking out of the edge, no matter what abrasives I use, or how much I vary my pressure, angle and sharpening techniques. It's been sharpened many times. I might experiment on that and report back.

Sounds like your pm2 is just one of those random s30v models that lacks apex stability. I've come.across them before from most companies who use that steel. I just stick to extra coarse edges and call it a day.

I don't know if it's related, but would like to share an experience I had with s30v.

I received a brand new sage 1 that during sharpening, the edge would crumble away. It didn't matter what type abrasive or grit, nor how much pressure used, although the more pressure, the more crumbling.
I could hear the popping and cracking of the edge and feel the pieces rolling under the bevel as they broke away.

This is the only knife I ever thought of sending to the manufacturer, but instead decided to just keep grinding away.
By the time I had removed about 1mm from the edge, I was getting more useable edges and sharpening was feeling more normal, but the finer edges were going away pretty fast with micro chipping.
With about 1/2 that much more removed, I get razor blade refined and sharp edges that keep the fine edge sharpness I expect.

Although I've had my share of less than satisfactory edges from the factory, none have been as extreme as this one, including other s30v.

[Pelagic]

Speaking of, do you guys have a recommendation on brand of diamond spray (not paste)? All the ones I looked at seem to be 5 carats per oz.
Are they all mostly the same? Amazon has some from sharpeningdepot, CKTG carries a brand called Richmond(that advertises a “non-clumping formula”), then there’s GRS Tools brand which is twice as expensive. Hand America, wicked edge, rio grande etc.

Any recommendations?

Ken Schwartz's sprays are certainly some of the best.

[Doeswhateveraspidercan]

My takeaway from all this is, it is not the quality of diamonds but the quantity present in the substrate.

Pelagic’s solution is great add your own to paste.

Paste should be the safest, best method to go submicron with as the diamonds are trapped and can not get airborne.

Airborn submicron diamond particles are a problem, there are health concerns.

There is no way I am spraying sub micron diamonds in an essentially alcohol suspension for fast drying on the strop because they want quick evaporation so the diamonds are dry on the strop.

Shakes head, who was the wizard that thought this out?

Below 3 to 5 microns the human respiratory system can not catch and filter particles prior to penetration into the deep lung.

I have known this fact for years hence always wet sharpening, and wearing a respirators with grinders / sanders of any kind.

https://www.merckmanuals.com/home/lung- ... ory-system

[Pelagic]

Well I certainly think the shape of the abrasive has a large impact on cutting speed, edge finish, and other things. But I have no way of really viewing the shape or size of the abrasive myself, all I can do is increase the concentration and experiment through sharpening. If the edge is good, all is well.

[Cambertree]

Yes, Cambertree, I have a tip. Start with your weak hand and end on your dominant hand. Go slow. Just allow the "muscle memory" to form over several weeks. My hands are always the steadiest in the beginning of sharpening, and this is a big reason why I try to get the job done quickly. Of course, I can always take a break and come back, but I've found that I have a higher chance of maintaining the same angle throughout the sharpening if I do it all in one sitting. I use one hand to guide the tip for stability throughout each pass (similarly to how Vivi does it on his "sharpening is simple" video using a DMT XC), and before I begin full passes, I target any extra dull spots with back and forth motions. The full passes will clean up any irregularities in the bevel.

I think there are a lot of different ways to attain desirable edges that aren't often explored. I've stropped with 30-40 micron diamond powder dry on wood as an experiment. Even the largest of burrs have no chance. And the first time I did it, my s110v military surprisingly sliced a free hanging paper towel absolutely CLEAN. The whole idea of diamond powder came about by me thinking "what separates good diamond emulsions and compounds from cheap ones?" Of course, there is the actual shape of the diamonds, the amount of variation in size of the particles, and other factors to consider, but in the end it seemed like there is a higher concentration of diamonds. So I thought "let's add more diamonds and see what happens" and the result was a game changer. I just load my 3 micron strop with Tormek PA-70 (best deal there is for stropping compound, and perfect for adding diamonds - unfortunately I believe it only comes in 3 micron) and sprinkle a bit of 3 micron diamond powder on top while the surface is still wet, and rub it in with one finger. I think I have some TEMO and "DiamondTech" or something, cheap syringes from ebay. I wasn't even willing to fork out the cash for DMT diapaste, let alone HandAmerican, Jende, Ken Schwartz, etc. Generally I always try to see if I can get a more budget friendly option to work before splurging on top shelf products, and adding diamonds to cheap compounds. Sometimes people forget that the jewelry polishing market exists with all kinds of different compounds that can be used in knife sharpening. I'd rather try 4-5 different cheap unpopular products and have a learning experience as I find out how good they are instead of just buying one product that has a good reputation. Of course if none of the cheap options work well, I'll step it up, but I tend to try them first.

Sounds like your pm2 is just one of those random s30v models that lacks apex stability. I've come.across them before from most companies who use that steel. I just stick to extra coarse edges and call it a day.

Excellent, thanks for that tip, Pelagic. It'll be hard to break the ingrained muscle memory I have, but I want to start to develop my non dominant hand in that way, for benchstone sharpening.

Yes, gem polishing suppliers are an excellent source for pastes and sprays. I'll certainly check out that 0.1 micron diamond powder.

So when you were using your 3 micron strop on that Benchmade, that was 3 micron paste, loaded with additional 0.1 micron diamond powder?

I experimented a while ago with hanging denim strops and thin strips of hanging leather with alumina oxide, and now I'm curious how they might work with an aggressive diamond slurry worked into the fabric or leather.

Doeswhatever, thanks for the timely reminder on breathing in hazardous particulates as well. It's always worth remembering. Some of the alloys we sharpen are toxic to humans as well, if inhaled as abraded dust. I always use a light damping spray mist when sharpening.

Well I certainly think the shape of the abrasive has a large impact on cutting speed, edge finish, and other things. But I have no way of really viewing the shape or size of the abrasive myself, all I can do is increase the concentration and experiment through sharpening. If the edge is good, all is well.

It doesn't show the exact structure of your particular compounds, but I thought readers of this thread might find these SEM images of different abrasive particles interesting:

https://scienceofsharp.com/2014/12/04/a ... r-the-sem/

I don't know if it's related, but would like to share an experience I had with s30v.

I received a brand new sage 1 that during sharpening, the edge would crumble away. It didn't matter what type abrasive or grit, nor how much pressure used, although the more pressure, the more crumbling.
I could hear the popping and cracking of the edge and feel the pieces rolling under the bevel as they broke away.

This is the only knife I ever thought of sending to the manufacturer, but instead decided to just keep grinding away.
By the time I had removed about 1mm from the edge, I was getting more useable edges and sharpening was feeling more normal, but the finer edges were going away pretty fast with micro chipping.
With about 1/2 that much more removed, I get razor blade refined and sharp edges that keep the fine edge sharpness I expect.

Although I've had my share of less than satisfactory edges from the factory, none have been as extreme as this one, including other s30v.

Thanks for sharing that, Jpm2. Yes I was interested to read about your experience with that Sage 1 in another thread. Was the Sage 1 a Taichung model?

I've had exactly the same experience with my PM2. During sharpening I can sometimes feel tiny fragments popping off and crunching under the bevel. Stropping can make the edge even more ragged, and will sometimes leave a couple of sparkly little specks of steel which have broken off the apex on the strop. Microbevelling at 20dps on the brown rods doesn't seem to help.

I have sharpened it back a fair bit from the initial edge, including a complete destress, where I ground the edge perpendicular to a coarse stone before reestablishing a fresh apex.

I must have read and researched more on S30V than any other steel, in trying to troubleshoot this knife. It put me off the whole SxxV family of steels for a long time. No other knife has given me these issues including S110V, ZDP189, Maxamet and a custom fixed blade I have in S30V.

After a while, I have ended up with a Yo2 in S30V (purchased on the rationale that I wouldn't be using it as an EDC anyway) and a Lefty Millie and the Kapara (both because I had no other choice of steel). They all seem to have behaved ok, although I don't entirely trust them, due to my PM2 experience.

In the end after a lot of resharpening, I just decided to go with other steels and stop spending time trying to work out what was wrong with my techniques or abrasives or preferred edge thickness and finish in relation to that knife.

I brought it out again recently, after reading the recent S30V threads and resharpened it on the Venev stones. Bang, same issues. Stropping and lightly microbevelling on the SM have made it even more ragged at the apex.

Based on what you and Pelagic mentioned, I'll try again to sharpen back to fresher steel and a coarser finish. In general, I think people are often way too quick to attribute a problem to the knife itself or heat treatment, when the problem is much more likely to be with the user. In this case, I feel like I'm running out of options for alternative approaches, and it actually may be possible that it's a heat treat issue.

Speaking of, do you guys have a recommendation on brand of diamond spray (not paste)? All the ones I looked at seem to be 5 carats per oz.
Are they all mostly the same? Amazon has some from sharpeningdepot, CKTG carries a brand called Richmond(that advertises a “non-clumping formula”), then there’s GRS Tools brand which is twice as expensive. Hand America, wicked edge, rio grande etc.

Any recommendations?

I use the Jende diamond and CBN emulsions and have been very happy with them.

[bbturbodad]

Sometimes people forget that the jewelry polishing market exists with all kinds of different compounds that can be used in knife sharpening.

Yep my wife is a jeweler and I steal borrow lapping films and tools from her all the time. :D