Ideal Stone/Plate Set for Edge Pro

Guys, I’m gonna get an Edge Pro Apex. I want to be able to set edges at known angles in order to make very precise changes to cutting ability and durability as well as making comparisons between knives/steels when edge angle is the same.

The question is what would be an all-around stone setup, an array of stones and plates for the three key steps in sharpening:

1. Shaping
2. Preparing the edge to take an apex
3. Setting the apex

I’ll have to have a set of different abrasives that I can use for everything from 420/1055 class steels up to S90V/XHP/M4 class steels.

Right now I’m looking at an Atoma 140 for shaping of the high-carbide steels, since it will work well with light pressure and high-carbide steels. Not sure about what to use on the simple steels for shaping. Not sure what to use for the 2nd step, in freehand I use a SuperStone 400. And for setting the apex of knives I’ll use an Atoma 1200, and probably at least two other ones for times a higher polish is wanted.

What do you guys think? Have you ever looked at Gritomatic’s selection of stuff for the Edge Pro? Any experience with the various stones for the Edge Pro, and what might work well for the holes in the lineup I mentioned above?

Okay so Jende sells King 1K stones for the Edge Pro, they’re relatively inexpensive and I think will work very well as a replacement for the SuperStone 400, the effect is basically the same, it’s just that the King is a bit softer.

They also sell Spyderco Ceramics for the Edge Pro. The Atoma 1200, the Spyderco Medium, and the Spyderco Fine should do very nicely as a set of finishing stones.

In the interest of not having to ever worry about maintaining a flat surface, I may actually just stick with the Atoma 140 for all shaping. It will probably be a bit slower than other stuff but I think the flatness is worth it.

It might also be worth getting an Atoma 600 for the intermediate step between the extremely coarse 140 and the King 1K, especially when doing knives that already have the angle set and just need some maintenance instead of an actual geometry change.

Ryan,
I have been using fixed angle sharpeners for several years. I mostly use them for making a mirror edge. I did make a post on the Old Forum talking about using Cliff's Three Step method: [www.cliffstamp.com]

I am interested to see how your use of the same stone for the 3-Step work on the fixed angle system. I really like the Venev XXXC and XXC stones for changing the angle/re-profiling.

Jason are those Venev stones the Orion ones, the resin bonded diamonds?

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Ryan Nafe
Jason are those Venev stones the Orion ones, the resin bonded diamonds?

Kinda of, they are the 3 Set of combo stones from Venev, the Centuar Series but the older style of the Alpha Centuari that went from #100-#2000

So I ordered (from Gritomatic) the base model Edge Pro Apex, in addition to an organizer for 9 stones and a digital angle gage. I opted out of the Atoma plates for now and decided to just trust exactly what Gritomatic recommended for the stones, out of curiosity and to see what I think about what they think works well:

For general/average knives they recommended:

- Boride Ruby 150
- Boride T2 400
- Boride PC 1200

They recommended the Boride CS-HD for high-wear steels, they’re a silicon carbide and more friable stone as opposed to the harder bonded alox ones, and I got those in the exact same grit range as the set mentioned above: 150, 400, 1200.

As a finishing stone I decided to go with a Spyderco Medium Ceramic, in addition to a kangaroo strop that I’ll load with the DMT 6 micron paste I already have. That should be a good combination for most work, leaving knife with the edge off the ceramic for most things and using the strop afterwards if I want more push-cutting ability. Depending on the nature of the other stones it may be possible or even productive to use them to apex knives too, but I wanted something I knew would work well for that.

I also ordered one of the Boride Ruby 60 grit stones just to play around with. Who knows, maybe it’ll be useful. I believe the Ruby line is very similar to a Norton India, alox and a very hard vitrified bond, so a 60 grit stone of that type may be pretty decent for major angle changes. It’s worth experimenting with at the very least. It’s not often you see sharpening stones of 60 grit, that’s literally a 250 micron abrasive or 10X the size of the diamonds on my DMT Fine plate.

Ryan,
Interesting choice of stones, it will be good to see the results. I really would like to see how a 3step with correct 3step style stones would work on an Edge Pro Apex style sharpener.

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jasonstone20
Ryan,
Interesting choice of stones, it will be good to see the results. I really would like to see how a 3step with correct 3step style stones would work on an Edge Pro Apex style sharpener.

Yeah I figured that initially I’d just get what they recommended and see how it goes, just experiment. But eventually I’ll definitely get a SuperStone/King 1K type stone for the middle step. Probably also an Atoma 140 and 400 for the heavy grinding/shaping.

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Ryan Nafe
Yeah I figured that initially I’d just get what they recommended and see how it goes, just experiment.

For instance, if one or both of the 1,200 grit stones end up being quite friable and produce a thick mud, they might cover the same purpose as a SuperStone. Or if the 60 grit Ruby stone does what I suspect it will, it might be far better for significant angle changes than a diamond plate but still stay flat and only require minimal conditioning. I’m just gonna carefully observe how they work and see what’s what.

Ryan,
Ok, I see what you had in mind there. I had an inexpensive Apogee SiC stone, and it shed grit like crazy, but it wasn't the colloidal type mud, more like the King 220 or Suehiro no. 800 'Chemical' Stone, where it left a streaked grit pattern instead of a shot-peened one. I think the only way to see how the grit pattern is left on the edge is to try it and find out.

Yeah, I mean they say explicitly “Consider buying Ruby 150, T2 400 and PC 1200. These 3 stones are the best Boride stones for sharpening knives.” So I’m curious to see why they say that, what happens when I use those stones.

Also, here’s another quote that shows they actually have some understanding of stone performance, making a very clear distinction between how a stone works with one type of steel vs another: “It is advisable to use the CS-HD stone set to sharpen knives made of hard stainless steel or carbon steel. Use of CS-HD stones to sharpen knives made of soft steel is not recommended – this will cause the CS-HD stones to wear at increased rates.”

For a seller to make an observation like that and share it clearly with the customer isn’t exactly common among sharpening equipment sellers. It tells me they’re probably more observant and more familiar with the products they’re selling than average.


And the Spyderco Ceramic is something I know will work for the final apexing, so worst case scenario I just do the basic three-step sharpening without the addition of a SuperStone/King 1K type stone. Just grind until light just starts to stop reflecting, then elevate the angle a bit and set the apex on the hard ceramic. Should work just fine even if half or more of the stones aren’t what I’d hoped they’d be.

Ryan,
Yeah, I might try out some of those stones. I just got the 13k Sigma II Select 1x6" stone to complete the Sigma II Select stones I bought from Ben Spallos, which included every stone (240, 400, 1k, 1.2k, 3k, 6k, 10k) up to the 10k one. The only one that was missing was the 13k. I also might try out some 1x6" stones that more line up with the 3Step idea of sharpening. The only thing I don't like about fixed-angle sharpeners is that it is difficult to get angles that are <10°, which really increases cutting performance.

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jasonstone20
The only thing I don't like about fixed-angle sharpeners is that it is difficult to get angles that are <10°, which really increases cutting performance.

This is one thing I’m a little worried about. I’ll probably end up settling bevels at the lowest setting. There might be ways around this though, such as laying the primary grind on the surface instead of the parallel flats. That’s why I wanted the angle gage, so I can figure out how to get the lowest possible angle.

Edit to add: The Edge Pro Apex says it can go as low as 10 degrees per side, which should be plenty strong for most of what I’m doing, and would increase the cutting ability quite a lot. The exact angle will vary, however, based on the distance to the edge from the fulcrum point. But I think I can do a little experimenting and figure out a way to get lower angles by laying the primary grind on the platform, zeroing the gage on that, and then checking the angle of the stone. This should make it possible to go 3 to 6 DPS lower, but we’ll see.



Edited 1 time(s). Last edit at 02/08/2022 08:43AM by Ryan Nafe.

Initial experiments using the Benchmade Saddle Mountain gave the following results for the lowest obtainable angles with this particular knife and the flats on the blade resting on the table/platform:

- 8.5 DPS with the stock 3mm thick Edge Pro stones

- 7.5 DPS with the 6mm Gritomatic/Boride stones


That’s plenty low for me, I’m quite happy. For most things I’ll probably just set the edge at 10 DPS and then microbevel at 15 DPS. For some of the nice simple steels like my Boker carbon steel kitchen knife, Joe’s 1095 utility knife, etc., I might lower that even further with an edge bevel of 8 DPS and a microbevel at 12 DPS. But the 10/15 combo is likely to be the standard setup.

I’ll put up some pictures of the stones and the other stuff from Gritomatic this weekend. It’s all a lot better than I expected: great packing, clear individual labels on the stones, and the wooden box that holds nine stones is actually really nicely made, definitely worth $20. It should be interesting to work with this as opposed to my normal freehand routine.

Don’t know why I didn’t look this up beforehand, but before I start working with these various stones I’ll post the links to what the manufacturer says about their properties and construction:

CS-HD: [www.borideabrasives.com]

T2: [www.borideabrasives.com]

PC: [www.borideabrasives.com]

Ruby: [www.borideabrasives.com]


The Spyderco Medium Ceramic is actually a real Spyderco stone and there is branding on the aluminum plate it’s fixed to, so credit is given where it’s due.

The strop is kangaroo leather, very thin and hard, I’ll load that with the 6 micron DMT paste.

All of the Boride stones will have to have their corners rounded and perhaps a brief lapping to check flatness.

One aspect of the Edge Pro that I hadn’t thought of before was the degree to which it highlights the flaws in the factory edge and the primary grind. It’s really interesting. The Benchmade S90V skinning knife has a few inconsistencies in the edge and the primary grind is actually lopsided, one side of the 12 DPS edge is about twice the length of the other, it’s pretty bad.

Notes on the performance of the two CS-HD stones on the Benchmade S90V:

Pressure applied: Only the weight of the stone and the rod it’s attached to.


150:

- Bright satin finish (looks like a DMT F or C)
- Very minimal wear/grit loss
- Only a small amount of abrasive floating around in the water, no thick mud
- Doesn’t load at all
- No natural burr minimization


400:

- Hazy finish with visible coarse scratches
- Heavy mud, just like the SuperStone 400
- Decent grinding speed, seems in line with the grit rating
- Doesn’t load at all
- Natural burr minimization is very good, very similar to the SuperStone 400




I’ll post more results of these when I try different steels and/or different pressures. As well as the same kind of notes for the other stones.

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Ryan Nafe
One aspect of the Edge Pro that I hadn’t thought of before was the degree to which it highlights the flaws in the factory edge and the primary grind. It’s really interesting. The Benchmade S90V skinning knife has a few inconsistencies in the edge and the primary grind is actually lopsided, one side of the 12 DPS edge is about twice the length of the other, it’s pretty bad.

Yes, this is why you need an XXC stone to reprofile/regrind an edge bevel.

I’ll do a few other knives this weekend, I’m gonna go pick up some painter’s tape right now. Can’t find my other roll. It’s good for keeping grit out of the action/pivot area of folders, that’s part of why I started with the fixed blade last night.

So after I sharpened the Benchmade I also reprofiled and sharpened the Nata and the Cold Steel Drop-Forged Survivalist. I’ll upload a video later tonight of some thoughts on how all that went and how the stones are performing so far.

Something I’ll note first is that the Ruby stones are not to my liking so far, the 150 loads with swarf and the 60 simply breaks down too fast and the loose grit is so large that it will scratch the primary grind above the edge.

The 400 and 1200 CS-HD stones, however, appear to be extremely useful for preparing the edge to take an apex or actually setting the apex with a bias towards durability relative to the edge finish of the stone. For a kitchen knife, for example, I would actually finish the apex without a microbevel on the 1200 and then make a few passes with the DMT paste strop at a one degree higher angle, this leaves a very sharp (clean shaving) edge but the combination of the muddy stone and the strop will leave the apex very resistant to rolling, so it should last a very long time in the kitchen.

One last thing is that I do indeed think that this system would be best utilized with something like the Atoma diamond plates. It’s difficult to use this with very much pressure, and stones going out of flat will cause issues with angle consistency. Given those two things, I think using diamond plates of one kind or another would be ideal, since diamonds are best with low pressure anyway and they don’t go out of flat, meaning they should be the most consistent option across a wide range of steels and a long period of use.

[www.bitchute.com]

I think I may have figured out what was happening with the CS-HD 150:

It simply doesn’t break down to a significant degree at those PSI levels, so instead of loading with steel like I thought it was, it’s actually just worn abrasive primarily. The abrasive isn’t releasing from the stone, it’s just wearing down. Which is a problem.

Ryan,
I haven't watched the video yet, but I will first thing.

What are you using for a lubricant? Maybe use oil with the 150 if you can.

Ryan,
Or maybe also use the 150 as an XXC finishing stone?

Ryan,
Another idea about the 150 stone. Try forming a slurry on the stone before use and see what happens.

Jason I think I just need to find the pressure level that actually breaks it down. And yeah oil is a good idea considering how non-friable it is.

Ryan,
I would give hand sharpening with the stone a try, as there is only so much force you can apply with the Edge Pro Apex. I would use a stone holder if you have one, I learned the hard way and ended up with a trip to the Emergency Room and five or six stitches in my hand from holding the Spyderco Tri-Angle rods in my hand and losing focus for a split second.

Yeah there are a lot of ways to see how much pressure it takes. Just gotta see what happens. Flatten it with the Cubitron if necessary.

So, a couple updates:

- The Boride CS-HD 150 is soft enough to be easily flattened/reconditioned on my 10x4 DMT XC plate.

- The angle control of the Edge Pro, in combination with the ease of using low pressures, makes it unbelievably easy to get extremely sharp edges.


The Chief XHP right now, after the 3-step process that ended with the Spyderco Medium Ceramic, is truly sharp. Push cutting receipt paper across the grain and shaving my forearms on both sides with no irritation or skin piling up on the edge. For the 3rd step, apexing the knife, just raise the angle a little bit and make alternating passes on each side, cross the scratch pattern a couple times near the end, then make one final very light pass on each side.

The angle control of the Edge Pro Apex makes this extremely simple and consistent, much easier than freehand once you’re used to the way the system works.

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Ryan Nafe
The Benchmade S90V skinning knife has a few inconsistencies in the edge and the primary grind is actually lopsided, one side of the 12 DPS edge is about twice the length of the other, it’s pretty bad.

This isn’t true, as it turns out. Here’s what’s really going on:

The angle I measure during setup is when the stone and the edge have no wear on them. The stone is at the starting thickness, the edge angle is at the starting edge angle. By the time the edge has actually been apexed (or very very nearly) with the coarse stone, a combination of the steel removal and the slight stone wear has actually caused the angle to gradually increase from the starting measurement. This is only a real issue with major angle changes, areas where a lot of steel will be removed.

I’ve never seen anyone talk about this. But it looks like I’ll have to aim for as much as 2 to 3 DPS lower than what I want the edge to be formed at, when doing angle changes.

I also ordered an Atoma 140 this morning.