Thread: Arkansas Surgical Black

I have such a stone ~2x8",mounted on a wood base with a wood cover. I think it came from Woodcraft Supply 15 yrs ago. I use it to do a final edge finish on my hardwood chisels (with very thin honing oil).

Anyone have any idea what the effective "grit" size might be on this? It is very fine relative to other hard Arkansas stones I have, and has the sense of being "harder". It is uniformly almost completely black.

Just curious and figured one of you has had their hands and maybe blades on such a stone.

Thanks in advance.

The effective grit size is about 1000 grit.

Arkansas hones work a little differently to a regular hone. They don't shed grit when they abrade.

What actually happens is the grit is held fast in the matrix, and you slowly grind through the grit. This is why these stones take a super polished finish and glaze up on the surface like glass.

As such Arkansas stones don't have a grit rating. They have a "level of finish". The smoother and more coherent the finish is, the slower the hone will work, and the finer the outcome.

There are a lot of people who have an Arkansas hone, I have one myself. And most people either have Translucent or Black as a finishing stone with the highest level of finish they can achive.

The level of finish is attained by firstly leveling the hone on wet and dry paper or lapidary compounds. At about 400 grit.

Then they take that through the grit system to as high as they can get it.

Then they abuse the hone with a chisel or blade till the glaze has taken hold.

You can spend several hours on every step and no 2 hones finish in an identical way.

That is what they say… about the grit rating, but I do not know where that comes from really. First you cannot grit rate a natural stone because they are all literally different and may be very different from one side to the other. I don’t know what the rating would be but the equivalent rating should be much higher… At least mine are… in my opinion.

What I do with natural stones is compare the stria to that of a known grit synthetic stone to get an idea of a grit range. But a Black Surgical will leave a hazy Kazumi stria pattern, making it difficult to compare and range it. And Grit range is not always an indicator of performance, of a razor stone.

As said, a lot will depend on how the stone has been prepped.

If you have been honing chisels on it for years and it is smooth as glass, it should be a finisher post 8K.

They also work well with a micro bevel with an extra piece of tape and 5-6 laps after polishing the bevel with 100 plus laps. Grit Rating of your stone, don’t know but they, unquestionably have the potential to be a very fine finisher.

Oil works, as does water and Smiths Honing Solution.

How about a photo?

Someone I trust just yesterday said his black shaved similar to an 8k. He's got "credentials" if that helps at all.

I know I'll be buying one soon to give a whirl. Though I intend to use them 99% of the time on knives, if I get a good one, I am not adverse to adding it into the razor rotation.

All said and done, you can buy a 2x6 on the cheap if you are OK with the size. I like palm honing - so I am OK with a smaller rock. .

Edit - sorry about the "you can buy one" comment. I forgot you had one.

Euclid, the thing with arkansas hones (with regard to final finishers like hard black, surgical and translucent) is that the hard abrasive particles are held in an equally hard matrix.

That means that you could have few abrasive particles spread sparsely throughout the matrix or very many abrasive particles tightly packed together in the matrix, or any variation in between.

Like Iceni said, the grit rating equivalent if given in the conventional way (which in itself is just a handy rule of thumb for the basis of comparison only) is disappointingly low. But hard arkansas hones are measured differently, by specific gravity. This is possible because the abrasive particles are not the same weight as the matrix, so sg measurements easily and accurately give us a measure of the abrasiveness. The method in essence consists of weighing the rock suspended in air the weighing again suspended in water, though you have to do a bit of simple jiggery-pokery to arrive at the sg figure.

That they are finishers, particularly the white translucent variety, is not questionable, Lyn has used them as such, Mastro Livi uses them (or at least used them on a regular basis some years ago), and even my humble self used one for some years to finish other peoples razors with, receiving not one complaint.

They take a bit of work to lap flat as stated in numerous other threads, but going above 600 grit results in a fair face that soon smooths up to resemble glass once a few razors have been passed over it. They are very slow and take a lot of laps, but they do leave a crisp, sharp edge.

FWIW I used to raise a very thin slurry with a fine DMT credit card size diamond hone - worked a treat if you diluted it as honing progressed until you finished on plain water.

Thin honing oil is also a good option, especially as most of the vintage ones were used as oilstones and became fairly saturated with oil. Failing that a dash of dish soap in the water will stop it beading up on a hone with slight traces of oil still in it.

Regards,
Neil

Neil, out of curiosity… what is your preferred finisher now?

My black Arkansas stone is a very fine finisher and I'm more than happy with it. I would rate it as near equal to a Shapton Pro 12000 as a finisher, although a fair bit slower It certainly improves the edge of a razor that has been worked on the so-called Chinese 12k (the PHIG). My example has an s.g. of 2.8 (calculated from its mass of 377g divided by the volume of 134 cm3). I have used both thin mineral oil and detergenty water as the honing medium - I can't say which is better.

As always, YMMV: my results pertain to my razors, my hones and about 4 years experience honing and shaving - I make no claims to honemeister status, I'm just a bloke who hones and shaves with his own razors.

Originally Posted by Euclid440

Neil, out of curiosity… what is your preferred finisher now?

Depends on the steel, really! Mainly its either the 20k Suehiro Gokumyo or a very hard hybrid (Les Latneuses) coticule. Both give sterling edges but the main concern for me is that they are fast.

Regards,
Neil

Thanks to all. Way more info than expected. I know perfectly understand the make-up of the stone material, and how it functions for blade material removal.

I can fully understand that the particle size may be equivalent to "1000 grit" but because so little of individual particles are revealed at the matrix surface, they behave more like a low density (particles/mm² on the surface) abrasive surface. Because the matrix is nearly as hard as the abrasive bits, and reveals so little of the particles, it cuts like the equivalent of a much higher "grit" stone. Surface particle density being low would cause the low stock removal rate.

I will try and get a picture before too long and add it to the thread.

Regards,

Not quite, The particle density on the Arkansas hones is actually very very high.

Take 2 trays filled with peanuts.

Tray 1 you pour on jelly over the peanuts to bind them.
Tray 2 you pour on toffee over the nuts to bind them.

Tray 1 if you rub your hand over it the peanuts come out of the jelly.
Tray 2 if you rub your hand on it the peanuts don't move at all.

With tray 1 the peanuts would be an abrasive, the size, shape, and hardness of the nuts would give you a grit rating, And smaller nuts would be a higher grit.

With tray 2 the peanuts don't move at all, You have to grind through them, So the surface just gets smoother and smoother. The only abrasive in action is the ground surface of the nuts and the powdered peanut parts.

Most hones act like tray 1 and have a grit rating dependent on the size of nut that gets released.

Arkansas hones act like tray 2 where there is very little been removed from the surface, The action of going through the nuts gives a very very fine powder, and the texture of the flattened nut with this powder gives the finished edge.

Hope that makes sense to you.