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Soft Arkansas : Gesswein

Posted by CliffStamp 
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Soft Arkansas : Gesswein
October 28, 2014 10:42PM
Arkansas sharpening stones are natural stones, meaning nothing more than they are just rocks unlike say a Norton India stone which is an abrasive in powder form which is made into the shape of a stone. The curious thing about Arkansas stones is that they have a very different reputation in the West than the corresponding stones have in the East. In Japan the natural stones are almost mystical in nature, being very expensive and often are attributed extreme behaviors and in general, very general, most would prefer to use natural stones if they were the same cost as the synthetic. However in the West there is a very different view and often the synthetic stones are simply viewed as better than the naturals because they are ideally consistent.

The natural stones being rocks are subject to variations in consistency and even though they are loosely graded based on hardness, not all "Soft" Arkansas stones are the same and if you poke around on the internet there are many claims made about one suppliers Arkansas stones being vastly superior to another. How much of this is true and how much approaches the kind of mystery which surrounds the Japanese stones I simply don't know, I just mention it as a point in passing. I would however just make a note of caution that the type of behavior I describe for this stone may not be found on another Soft Arkansas stone because again these are just rocks, they are not man made stones and thus they can vary as much as the guy who decided to grade them and give them that label.




This is a small stone : 1" thick, 2" wide and 6" long. These stones can come in huge slabs if you want. Dan's Whetstones even sells them in monsterous 12" x 3" slabs . The natural aspect of the stone is obvious if you look at it under magnification because you don't see something like this :



That is a SPS-II 240X stone and you can clearly see it is made from a bunch of abrasive grits stuck together, but here is what the Soft Arkansas stone looks like under the same magnification :



and more clearly :



What you have is more of a open (full of holes) structure where the individual crystals are very fine and in fact difficult to actually see. As for how it cuts, one way to see it very clearly is to take a piece of steel and give it a high polish :



and then make 25 passes under moderate force to generate a low contact pressure (0.25 psi) :



Then what you see are some very harsh scratches but they are very random and not very dense thus you would expect that this would give a fairly aggressive finish (rough edge) but the cutting speed is likely to be low. In comparison just look at the result of the same with the Suehiro 'Chemical' :



It is the same sort of harsh scratches but they are so dense that they basically erase the polish and thus you would expect a much higher cutting speed. However before we look at the low point of the stone, lets look at the strength because where it excels it really excels : [www.cliffstamp.com] . In short, for setting the apex this stone is in a different class than traditional waterstones. It can refine the apex and produce a much higher sharpness much easier. Why? Because it has no issues with the grit breaking down and the slurry grating into the apex directly and dulling it. There is just even abrasion against the edge and thus it is completely trivial to get sharpness which shaves above the skin. Now can this be achieved with the waterstones, well yes, it just takes a lot more time and a lot more finicky behavior trying to form the apex and minimize the burr and the damage.

However before we all throw away the waterstones we have to be a bit realistic about the Soft Arkansas and the downside is just as down as the up side is up. It is made from Novaculite which is a form of flint which is a type of quartz (silicon dioxide). This is a rather soft abrasive, the hardness is similar to fully hardened martensite so it is softer than all carbide, even cementite. For comparison, in a situation which is going to be as favorable for the Arkansas stone as it is going to get I reset the edge on a 3Cr13 stainless steel which is very low carbide and very soft and easy to grind. With a force applied of 2 lbs and a contact pressure of 2-4 psi the Naniwa Superstone 400 reset the bevel three times with :

-75, 75 and 85 pps required

With the Soft Arkansas, the first time took 550 pps, however before too much is made of that it has to be realized that the Soft Arkansas is very flat and it doesn't wear compared to the Superstone and thus it actually flattens the edge bevel during this honing. The next two times it was repeated the pass count dropped down to :

-250, 275 pps

But still it is very slow compared to the Nanwa Superstone 400 which itself is not generally regarded as a fast waterstone. In fact it is one of the slower cutting waterstones for its cutting speed yet it completely outclasses the Soft Arkansas -and- gives a much finer finish. But again the Soft Arkansas is much easier to actually set the apex and the wear rate is much lower.

--

How will I likely use this, mainly it will be a teaching tool as it is one of the best stones for someone to learn how to sharpen, especially if they take the two stage approach I tend to favor.

a) shape

b) apex

It is very easy to show someone how to shape an edge, just remove the light reflecting and produce an edge which can slice paper at some level and then this stone micro-bevels easily (on high grindability steels) :



If this is paired with a decent shaping stone, say the Suehiro 'Chemical' and used on simple knives it is likely someone who was shown that method of sharpening with those stones would wonder why anyone ever though it was difficult at all. Now you could say well why not use diamonds? Well you can but a beginner can easily gouge diamonds and otherwise damage the surface. This stone is easily used with water (I use a chemical additive to reduce rust (Honerite Gold) and is pretty much immune to being damaged unless you subject it to a severe impact. Plus beginners normally have easy to grind knives anyway.

--

As a general aside, there is almost no discussion of using a slurry on these stones which is very common with Japanese waterstones. There is nothing stopping you from doing so and it would vastly increase the cutting speed -but- unless you are forced to just use a stone which is inherently going to do that anyway. If you put 90X silicon carbide on this stone it will likely cut at a rate similar to the Suehiro 'Chemical' but you could just as easily put that silicon carbide powder on a piece of iron and do the same thing as when the grit is doing the cutting the stone really doesn't matter. But if you have a lot of powders or just like to play with things, you could use this as a one-stone option by combining it with very harsh loose abrasives and then generating a very fine slurry later on to refine the finish.
Re: Soft Arkansas : Gesswein
October 29, 2014 02:54AM
I really like these stones for finishing and micro-beveling. If used for the later steps in sharpening, you can aviod some of their drawbacks.
Re: Soft Arkansas : Gesswein
October 29, 2014 03:27AM
I have a soft smiths stone, and a hard black stone from Dan's whetstones. Only downside for me is that they don't cut high carbide steels very effectively
Re: Soft Arkansas : Gesswein
October 29, 2014 06:40AM
Thank you for taking a quantitative look at these, Cliff.

I know of plenty of guys who use these stones for the sole reason that it was what a relative or known good ol boy would use to sharpen their knives. For something like carbon steel or 440A equivalent steels they all are pretty happy with them. That being said, a lot of them either have low standards of sharpness or sharpen in a ritualized manner, so I can't say much about their results.

I'll stick to a friable SiC stone for grinding and the Norton India for finishing myself. I ain't got the patience for these.

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Bill22252 on YouTube. "See you space cowboy"

Resident Emerson Fanboi

Folding knives are fun, fixed blades are important.
Re: Soft Arkansas : Gesswein
October 29, 2014 02:00PM
Quote
Bugout Bill

[...]

I'll stick to a friable SiC stone for grinding and the Norton India for finishing myself. I ain't got the patience for these.

That argument is very difficult to actually content, hence why Arkansas stones don't have the kind of attachment that the Japanese equivalent seems to generate. It is very easy to find a synthetic stone which has whatever combination of abrasive friabilty and binder strength that you want. The really nice thing is that you can then recommend this to someone based on known ability and you can modify it as well with statements like :

-The TASK is similar to the Sigma Power 120 but the TASK has a much weaker bond so it works better with less pressure and/or on harder to cut steels

With natural stones there is a lot of variation and trying to make those kinds of statements is next to impossible. Still though, for all of these drawbacks, if you use them similar to the Spyderco ceramics and just micro-bevel they work well. At a minimum I would at least recommend you try them once just to see how setting an apex can be so trivial.
Re: Soft Arkansas : Gesswein
October 29, 2014 02:41PM
i wish i knew more about that natural stone i got form Kyle that he got from you. it has very similar properties to this but it leaves what i am guessing is a finer finish.

this stone you have would be considered a "fast cutting" stone correct?

www.theflatearthsociety.org

BIGFOOT FINDS YOU, YOU DON'T FIND BIGFOOT!



IT IS THE E-NEP THROWING BROTHERHOOD
Re: Soft Arkansas : Gesswein
October 29, 2014 03:22PM
Quote
Mark a

t has very similar properties to this but it leaves what i am guessing is a finer finish.

In what way, it is almost the opposite aside from it being a rock/natural stone. It is a very soft stone, easy to gouge. Nice to polish/finish, difficult to apex in the same way most waterstones are.

Quote


this stone you have would be considered a "fast cutting" stone correct?

The Soft Arkansas?
Re: Soft Arkansas : Gesswein
October 29, 2014 03:46PM
I actually thought that stone I have was fairly easy to apex with. It gives what might be the sharpest edge with the least work of any of my stones.

Yes I meant the soft Arkansas stone you have. It is considered (as Arkansas stones go) fast cutting.

www.theflatearthsociety.org

BIGFOOT FINDS YOU, YOU DON'T FIND BIGFOOT!



IT IS THE E-NEP THROWING BROTHERHOOD
Re: Soft Arkansas : Gesswein
October 29, 2014 04:12PM
Cliff: Are you intending to use these on more wear resistant steels?

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Bill22252 on YouTube. "See you space cowboy"

Resident Emerson Fanboi

Folding knives are fun, fixed blades are important.
Re: Soft Arkansas : Gesswein
October 29, 2014 04:14PM
The problem with comparing rate of cutting is what is being measured exactly. If it is absolute speed then it is fairly low as it is going to be in the 1-2 k waterstone class and closer towards the 2k. If it is in terms of some kind of speed as a function of finish (harshness of scratch pattern) it is not high either and for example it is both far slower than the Naniwa Superstone 400 and gives a much more harsh finish (takes longer with a finer stone to replace the abrasive pattern). If however you compare it to just other Arkansas stones, well it is much faster t grind than the hard black I have which is similar to a Spyderco ultra-fine.

In regards to ease of forming an apex, I am referring to forming the micro-bevel and obtaining a sharpness on the level of cutting hair above the skin, push cutting newsprint etc. . Before that the knife is already sharp enough to easily slice newsprint. That chinese waterstone is pretty soft. If I was using it then I would have to use burr minimization techniques and take care not to cut the stone. With the soft Arkansas stone I don't have to do pretty much anything like that at all, hence I would say the chinese is much harder to use to form the apex.

For example the medium spyderco stone is among the easiest stones to form an apex, but if the knife is actually dull it isn't overly useful as the stone will load before the apex is even formed. In that case I would want the Naniwa Superstone 400 or Suehiro 'Chemical' and put up with the more extensive burr minimization required to allow the much faster rate of grinding.

But if you actually do like that kind of soft stone for actually forming an apex then you are either sharpening much different than I am, or simply far more skilled or some combination of the same. I would be curious to see a video of you using that stone and the kind of sharpness you obtain from it.



Edited 1 time(s). Last edit at 10/29/2014 04:24PM by CliffStamp.
Re: Soft Arkansas : Gesswein
October 29, 2014 04:15PM
Quote
Bugout Bill
Are you intending to use these on more wear resistant steels?


Yes, both for evaluation purposes and curiosity.
Re: Soft Arkansas : Gesswein
October 29, 2014 04:42PM
I may have to get one of these Arkansas stones seems like it may be an interesting stone.
With regards to that Chinese stone it seems quite a bit harder than my king 1k stone. I have cut that one several times. I have used the Chinese stone as a finishing stone for my razor with decent results. I will get a video up when I have some time.

www.theflatearthsociety.org

BIGFOOT FINDS YOU, YOU DON'T FIND BIGFOOT!



IT IS THE E-NEP THROWING BROTHERHOOD
Re: Soft Arkansas : Gesswein
October 29, 2014 05:04PM
The Kings are really soft, I think only Colin is crazy enough to actually try to apex on them. I think it would be an interesting thing to try to find the stone / steel mating challenge like for example which is easier :

-King 1000 on AEB-L/Kyley

-Soft Arkansas on 12C27/Bark River
Re: Soft Arkansas : Gesswein
October 29, 2014 05:13PM
I would be interested to see how difficult it would be to do damage removal on something like 8CR13MOV. That is one of the big reasons why I am rather hesitant to try or recommend Arkansas stones to new sharpeners over something like a Ace AlOX or SiC stone.

---------------------------------------------------------------------------------------------------------------------------------------

Bill22252 on YouTube. "See you space cowboy"

Resident Emerson Fanboi

Folding knives are fun, fixed blades are important.
Re: Soft Arkansas : Gesswein
October 29, 2014 05:28PM
I would not because it would take a LONG time. When I set the apex on the 3Cr13 in those edge retention runs in the above, the apex has no damage is is approximately 20-40 microns wide, it it still takes ~250 pps to form. In comparison, the Naniwa Superstone 400, which itself isn't a fast cutting stone is 1/5 the pass count.

If you actually had to remove visible damage on a harder to grind steel then you better settle in for some serious grinding time and/or extremely heavy down pressure. I don't see it as practical at all for shaping/grinding. However maybe I just have a really slow cutting one, I have only used a half a dozen Arkansas stones (2 soft, 2 black, 2 of the translucent).



Edited 1 time(s). Last edit at 10/29/2014 05:36PM by CliffStamp.
Re: Soft Arkansas : Gesswein
October 29, 2014 05:38PM
Cliff: For the people who I know that use their knives, I imagine that they usually resort to heavy pressure and time. A lot of them use 440A or 8CR knives and usually get them damaged in the sense that there are rolls and chips.

---------------------------------------------------------------------------------------------------------------------------------------

Bill22252 on YouTube. "See you space cowboy"

Resident Emerson Fanboi

Folding knives are fun, fixed blades are important.
Re: Soft Arkansas : Gesswein
October 29, 2014 06:53PM
No doubt, I see people on YT pressing so hard the stone rocks/shakes. The problem I have with that is simply one of efficiency. The problem with these stones really comes if you compare them to the synthetics as they are also very hard and slow wearing. Just see how many people are lapping the Norton silicon carbide or aluminum oxide stones frequently. I really think the most sensible use of these stones are for micro-bevels or similar just like the solid Spyderco ceramics. But then again there are people who love to sharpen and have literally 30 minute+ videos of them just stropping or messing about with ultra-fine stones.
Re: Soft Arkansas : Gesswein
October 29, 2014 07:05PM
It's interesting that you bring up lapping AlOx stones. I find that to be almost a necessity with my Norton India unless I use it heavily lubed due to the fact that it loads pretty badly, particularly the coarse side.

Now for something like a carbon steel pocket knife, I have heard of people sharpening them by simply laying the blade flat and planning it down. For that application, the high finish that Arkansas stones can provide is likely very desirable.

I'm going to await further results on this stone before I make any conclusions. If it can microbevel higher carbide steels with similar efficiency and sharpness to Spyderco stones, I might be interested in picking one up.

---------------------------------------------------------------------------------------------------------------------------------------

Bill22252 on YouTube. "See you space cowboy"

Resident Emerson Fanboi

Folding knives are fun, fixed blades are important.
Re: Soft Arkansas : Gesswein
October 29, 2014 09:01PM
These are some of my favorite stones and for the longest time, a 4" pocket soft stone was what i kept in my pocket for touching up my crkt m16 in 8cr15mov. I kept a piece of 400 grit wet/dry with it. Big enough to comfortably wrap the stone. Material removal with the sandpaper then I would lap the stone length ways to speed up the grinding a bit. Worked fairly quickly, leaving a very nice shaving finish.
me2
Re: Soft Arkansas : Gesswein
October 30, 2014 01:07AM
I suppose I should consider myself in good, if crazy, company. I tried apexing on the 1k and 4k king stones. The 4k is too soft to use for edge leading passes for apexing, at least for me. I lear ed to sharpen on a Soft Arkansas stone, whichmay account for some of my trouble with the softer stones. If you have any 12c27 type steel, try that on the Arkansas. I remember a Benchmade I repaired getting insanely sharp off my old one. I was never able to equal that edge on my Buck in 425 M.
Re: Soft Arkansas : Gesswein
November 13, 2014 02:54AM
As an update, I put about a hundred or so passes on this stone using water as a lubricant, it will soak into the stone readily. However the stone loads very easily and even after that amount of work the stone would produce a much finer finish, but it was mainly due to burnishing. It wasn't a finer scratch pattern specifically just the same scratches then being smeared out on occasion. The reduction in cutting speed was noticeable and the edge retention on a slice was cut in half (slicing hemp).

It was pretty trivial to undo however, just a little grinding with the King 1000 and it was perfectly fine again, and the King 1000 was also flattened in the process. This makes a pretty decent pair as the King 1000 is much nicer / faster to grind and polish the flats/edge but the Arkansas is much easier to set the apex. I am going to repeat this a few times and then dry it wit some detergent/degreased and finally oil.
Re: Soft Arkansas : Gesswein
November 13, 2014 03:26AM
Quote
CliffStamp
As an update, I put about a hundred or so passes on this stone using water as a lubricant, it will soak into the stone readily. However the stone loads very easily and even after that amount of work the stone would produce a much finer finish, but it was mainly due to burnishing. It wasn't a finer scratch pattern specifically just the same scratches then being smeared out on occasion. The reduction in cutting speed was noticeable and the edge retention on a slice was cut in half (slicing hemp).

It was pretty trivial to undo however, just a little grinding with the King 1000 and it was perfectly fine again, and the King 1000 was also flattened in the process. This makes a pretty decent pair as the King 1000 is much nicer / faster to grind and polish the flats/edge but the Arkansas is much easier to set the apex. I am going to repeat this a few times and then dry it wit some detergent/degreased and finally oil.

For the Arkansas stone, I'd recommend a drop of dishwashing detergant in a small bottle of water, works wonders on Arkansas stones that load up.

Also, what about the Chinese stone? The one you gave to Mark A? Is that the Chinese 12k natural waterstone you can get from Amazon? Is it worth getting? I've heard mixed reviews, and some say you have to try a few stones before you get a good one. Is it worth the $25-$35 dollar risk?
Re: Soft Arkansas : Gesswein
November 13, 2014 02:10PM
Quote
jasonstone20

[...]

Is that the Chinese 12k natural waterstone you can get from Amazon?

No, it was one of a set of two I was give to a friend he picked up locally. It is a very soft stone, almost like chalk and would be either very frustrating or very pleasant to use depending on how you try to use it. If you look on the forums then Mark and Kyle had almost the exact opposite reaction to it.
Re: Soft Arkansas : Gesswein
March 31, 2015 02:56AM
I have been using this a little lately and it is interesting how it is the completely opposite of the Naniwa Superstone 400 and how well they work together.

The Superstone is coarse enough to grind dull knives back to sharp very quickly (as in 1-2 minutes even on very dull knives) and it leaves an edge almost perfect for a micro-bevel because of the natural way it achieves burr minimization through the thick, though fine slurry. The Arkansas stone is then able to apply a very fine high push cutting sharpness with just a few passes. These two stages of sharpening are so very different that I have been teaching them completely separately to try to get people to think on them differently.

It is like when changing a tire, you would never confuse jacking up the care with removing the lugs. They are part of changing the tire but they are completely different tasks though they both involve the car, just like both of the above steps involve a stone. I have taken knives I have prepared on the Superstone and given them to people and shown them how to micro-bevel on the Arkansas and they are shocked that sharpening is so easy. And then I have taken a dull knife and shown them how to do the basic first stage on the Naniwa Superstone and they are shocked that is so easy.

Putting both steps together is then trivial. But if you switched stones it would be like trying to remove the lugs on a tire with a jack, it just doesn't work. The Naniwa Superstone is a horrible choice to micro-bevel and the Arkansas is just as bad to grind to grind an edge that is dull to form an apex. Assuming you even have the patience to do it, the stone is going to load, burnishing is going to happen, the edge will burr and if you tried to micro-bevel on that mess with the Naniwa you would wonder why anyone sharpens at all.

--

A very nice page on these stones :

- [www.cookfoodgood.com]
Eli
Re: Soft Arkansas : Gesswein
March 31, 2015 05:38AM
May I suggest "Smith's honing solution" instead of oil for the Arkansas stone? It works as well as oil without the residue. It is also recommended at SRP as lubricant/oil replacement (and I only use it for straights). I don't use my Arkansas stones with oil. I have raised slurry on my Arkansas stones, either using pressure or a J-nat. I like to think of the hard/mildly translucent grade as corresponding to Suita. A bit porous, a bit coarse, but fast. But I didn't like that they crack so quickly, either under pressure or banging against something. I haven't used them in a while in the kitchen.

As for the Chinese 12k. I have a few from Woodcraft. (Different sources probably have different stones.) My 8x3 creates an uncomfortable edge with razors, but several 8x2 were fine. Slightly blue. Medium hard for razors, probably too hard for J-knives, but might be ok with Western knives and light pressure. Didn't use the C12K much with knives, but for razors well worth the risk. I also got a C2K from the Bay. It is one super hard stone. Have not finished lapping it. If that is a 2K stone I don't know. Will probably not cut much or require regular roughing using the diamond plates.
Re: Soft Arkansas : Gesswein
March 31, 2015 03:07PM
Have you use the Smith's directly against / compared to an oil? I use mineral oil which has no residue, the only real issue I have with it is cost (over water). There is a minor issue of the way I sharpen in getting oil on my off hand, but again it is mainly because of how I sharpen and I could fix that with a small holding block.
Eli
Re: Soft Arkansas : Gesswein
March 31, 2015 05:38PM
I have compared Smith's to water and soap. I can't notice much difference between water and soap, but Smith's is better than either for straight razors (more agreeable shave - I don't care for sharpness tests). I may have tried food grade mineral oil on a Charnley forest, but I don't recall. I can't stand the smell of most oil. I have removed oil from an old carborundum razor hone with decent success. With naturals I have spent a lot of chemicals and time cleaning with plenty residue/smell remaining. There are a few glass-like stones like Charnley Forest that don't take oil, but anything mildly porous is lost. As for straight razors I have repeatedly read good things about sewing machine oil, but I think it is smelly? Never read that the choice of oil would matter for knives.
Re: Soft Arkansas : Gesswein
March 31, 2015 08:28PM
Food grade oil isn't a good choice because it will oxidize as it goes rancid. All you need is plain mineral oil, baby oil is a light mineral oil lightly scented. Raw mineral oil doesn't smell like most of anything.

I have used oil vs detergents and water based lubricants, in general the oil will keep a stone cutting better for longer as it reduces abrasive wear. Putting oil on a worn stone can in fact bring the worn surface back to life as it can make it start cutting again. As the stones get finer and finer this stops being much of an issue, on the fairly coarse stones however the effect can be rather dramatic.
Re: Soft Arkansas : Gesswein
April 01, 2015 01:11AM
As an update, as part of the writeup I did a short experiment :



OTK EDC : k390 / 64 HRC

This is the edge off the Naniwa Aotoshi 2000 :



There was no attempt to sharpen this, I just created an apex, no burr minimization but none is needed as this generates decent slurry. The sharpness on Espirit :

-150 to 280 grams

This isn't that impressive, won't shave, slices newsprint trivially, won't push cut. But again not trying to sharpen it, just set the edge for the micro-bevel.

I did 5 passes on the Soft Arkansas (mineral oil), then 5 more ultra-light. This was supposed to do nothing, at most just push the edge to one side and then the other.

The first surprise was that it was abrasive, or it felt like it was abrasive, did not feel slick. The second surprise :



It clearly makes a micro-bevel. The third surprise, sharpness on Espirit :

-60 to 110 grams

Shaves arm hair with the lightest touch, both sides of the edge, push cuts newsprint trivially.

Now something is up here because 820 Knoop should not be able to do that. But there is a problem with that statistic even though it is all over the place :

-crystals have different hardness values depending on what face they are measured
-no measurement comes out that exact, it is a rounded number

I did some checking and finally found what I was looking for :

"The value given for quartz is 1181 kg/mm2, but it is larger on the m prism faces (1260 kg/mm2) than on the basal plane c (1103 kg/mm2), an obvious anisotropy. "

This is Vicker's hardness and these are real unrounded measurements.

- [www.quartzpage.de]

Now care has to be taken in moving from one hardness measurement to the other, but just roughly, these Vickers measurements are > 70 HRC.

Now most people site the hardness of these stones as 820 Knoop which should not be able to cut this steel. But it does and more precise measurements of quartz clearly show it is able to.
Re: Soft Arkansas : Gesswein
April 01, 2015 01:40AM
Dang.

That's pretty remarkable. What happens if you do the same with a spyderco uf?

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Bill22252 on YouTube. "See you space cowboy"

Resident Emerson Fanboi

Folding knives are fun, fixed blades are important.