Now I have a pair of natural stones... Ha!!

[bmiller3230]

So, my honing progression has been Norton 250/1k combo (only using the 1k for bevel setting), then Norton 4k/8k, then Naniwa 12k, recently replaced with an ILR after watching Dr Matt's Youtube video. I actually think I found the secret sauce to that stone. And its not using it under running water. Its using a squirt bottle of plain water at the bench and doing some laps, then a squirt bottle of water with a little dish soap and doing laps, and finally using lather on the stone and doing laps. I think this has the effect of simulating progressively lighter pressure and I have had really good results using it this way.

But, I've been fascinated with all the talk on here about coticules and Arkansas stones so I bought these from Sharpening Supplies. Both are 6 inches X 2 inches.

I have two questions.

1) Is this really a Hard Black Arkansas? The reason I ask is it has been surprisingly easy to lap using my Norton Lapping stone that I use on my water stones. I read about nightmares trying to true them using W/D sand paper and other methods.

2) I understand color can be a tell tale regarding what a coticule is going to be like. Is that true? Just by touch this one seems very smooth and fine grained. I just got them and haven't honed on either stone yet. The coticule didn't come with a slurry stone, but I have one on order

Anyway, after my breakthrough with the ILR last night, these might be eBayed or end up on the BST section of this site.

But anyone familiar with them, please let me know what you know about them. Thanks!!

 

[Legion]

As far as the Ark, you might be able to get more of a clue by measuring the specific gravity. There are some companies selling black slates, sometimes called Dunston stones, and labelling them Hard Black Arkansas. They get away with it because Dunston stones are black and from Arkansas, but it does add confusion to the issue

Proper surgical black stones are novaculite rather than slate, and they are VERY hard. I've never used a Norton lapping stone, but my feeling is you would have trouble using it to remove material on a true hard Ark. I might be wrong about that, but as you say, they laugh at sandpaper for anything bellow some surface prep.

 

[Frank Shaves]

The Sharpening Supplies branded Arks are Dan's. I have a Sharpening Supplies Hard Black whose box also says "Black Hard Arkansas" on the top, so your stone should be the real deal.

I know that we are not supposed to talk about prices, but I assume that your receipt contains the digits circled in red:

 

[Frank Shaves]

I also have a Ardeness-Coticule Standard La Grise that I use for finishing with just water - great edges. 6 x 2 is a nice size.

 

[bmiller3230]

The Sharpening Supplies branded Arks are Dan's. I have a Sharpening Supplies Hard Black whose box also says "Black Hard Arkansas" on the top, so your stone should be the real deal.

I know that we are not supposed to talk about prices, but I assume that your receipt contains the digits circled in red:

View attachment 1607198

Yes, exactly that one

 

[Wid]

Both of those stones are high quality and both can give great edges.

 

[Gamma]

Hard Arkansas can be anything from almost soft to almost in the range of translucent stones. My personal term for this is 'regular hard' - they are pretty common on auction sites. People mistake them for a 'True Hard' or Surgical Black, or similar when the stone is just 'hard'. Measuring specific gravity assumes the stone is 100% novaculite, impurities can tip the scales and different materials like indurated slate can be measured but the resulting numbers aren't comparable to other types of stone. So if it is a Dunston, it's apples and oranges. I'm not saying it is or even might be, just making a point about testing... all that glitters is not gold.

One of the problems that people have had over the years, when buying Arks from middle-sellers, is that sometimes some vendors are 'known' to source supplies from one place, but actually use several sources, depending on inventory and availability. Customers of a well known woodworking tool site ran into this not so very long ago. Lotta unhappy 'Surgical Black' owners out there. There are many other stories involving many other sellers too. Honestly, out side of buying vintage, there are only a couple sources i'd trust to deliver an Ark. But, that's me. I just don't like surprises....

It's been ages since I touched a Norton flattening stone, they are almost never flat unless they are lapped first, which sorta defeats the purpose of having one. They never stayed flat either. I didn't find them good for natural stones, ok for some water stones to some degree though. But I am not holding the Ark in question to judge flatness - so it's hard to say. If it's flat and proven flat by a quality straight edge across multiple axes, it's flat.

 

[bmiller3230]

Hard Arkansas can be anything from almost soft to almost in the range of translucent stones. My personal term for this is 'regular hard' - they are pretty common on auction sites. People mistake them for a 'True Hard' or Surgical Black, or similar when the stone is just 'hard'. Measuring specific gravity assumes the stone is 100% novaculite, impurities can tip the scales and different materials like indurated slate can be measured but the resulting numbers aren't comparable to other types of stone. So if it is a Dunston, it's apples and oranges. I'm not saying it is or even might be, just making a point about testing... all that glitters is not gold.

One of the problems that people have had over the years, when buying Arks from middle-sellers, is that sometimes some vendors are 'known' to source supplies from one place, but actually use several sources, depending on inventory and availability. Customers of a well known woodworking tool site ran into this not so very long ago. Lotta unhappy 'Surgical Black' owners out there. There are many other stories involving many other sellers too. Honestly, out side of buying vintage, there are only a couple sources i'd trust to deliver an Ark. But, that's me. I just don't like surprises....

It's been ages since I touched a Norton flattening stone, they are almost never flat unless they are lapped first, which sorta defeats the purpose of having one. They never stayed flat either. I didn't find them good for natural stones, ok for some water stones to some degree though. But I am not holding the Ark in question to judge flatness - so it's hard to say. If it's flat and proven flat by a quality straight edge across multiple axes, it's flat.

No idea how to measure specific gravity. I just have that little metal ruler to check flatness, but I don't see light coming from under it

 

[Gamma]

Not all of my metal rulers are very straight.. my oldest is waaay off from using it to cut leather. Yours may be fine though.
These days I use a calibrated straight edge that is longer than the stone and I check across 8 axes.
Lengthways by both edges and the middle, short-ways at both ends and in the middle, and across both diagonals. With Arks, its not uncommon to find one long edge is 'in' while the other long edge is 'out'.

Your stone might be super hard, and very flat, dunno. Assumptions can lead to frustration though, double checking can help remove frustrating hidden variables.

Lep it, hone on it, see how it goes. If you like it you like it. That's all that matters at the end of the day.

 

[bmiller3230]

When I was lapping the "Ark", I marked a grid pattern in silver ink using a silver sharpie that I have that I use for labeling shotgun shells I load. I was measuring progress by the amount of that pattern removed by the lapping stone (using water, of course). The pattern was gradually removed from the edges in to the middle

 

[Legion]

No idea how to measure specific gravity. I just have that little metal ruler to check flatness, but I don't see light coming from under it

Here you go.

 

[duke762]

Specific gravity testing would probably be useless in your situation. In the Black/Trans, SG shoot outs, the Blacks can score higher due to high SG impurities, some of which cause the Black color. SG is not a measure of hardness however, it's density and weight compared to......well...anyhow.

Flatten it, dress it to about 600 wet/dry and give it a go and see how it works. I'd like to hear what happens.

 

[Kyle89]

Tried sending you a PM but I don't know if you have it turned off or if it's because you limit who can see your profile.

Anywho, how's the edge off of the maybe Ark?

 

[SliceOfLife]

Surface of that hard black definitely does not look lapped. If you took the picture before lapping... that's why it's easy to lap. That looks like SIC/abrasive powder blasted surface... meaning it's loose and craggy and will be VERY easy to lap... at first... and get progressively harder as you get closer to having it lapped. If that is after lapping... stop using that lapping stone... it's roughing up the surface, not lapping it. Get either wet/dry and a flat surface or a diamond plate.

 

[H Brad Boonshaft]

How many times did you grid mark and remove it completely?

It usually takes several grid marking and removal to get to flat. The grit and slurry wash off the sharpie long before the stone is flat. Pencil is useless on an Ark or hard stone.

A good test, a sharpie grid should be removed completely in less than 10 laps, ideally in a single lap. Got Grit.com sells a loose Silicone Carbide grit selection from 60-500 for about $15.

Most of the work, flattening is done on 60 grit, once flat you can run through the other grits quickly.

Sad that modern Ark purchase is such a gamble now days. You can buy a small vintage Ark for just a bit more and can finish a razor on a 4 or 6 inch stone easily.

 

[Gamma]

When I was lapping the "Ark", I marked a grid pattern in silver ink using a silver sharpie that I have that I use for labeling shotgun shells I load. I was measuring progress by the amount of that pattern removed by the lapping stone (using water, of course). The pattern was gradually removed from the edges in to the middle

This is a common but often unreliable method of gauging flatness. The grids can and do often wear off long before actual flatness is achieved. Sometimes, just to see how far 'out' things are, I start off with a grid to see where I am at. I use the straight edge as the final say when I am done. Arks can be a pita in this regard. Some go easier than others though - had a smaller Translucent recently that I was able to get dead-flat relatively easily. So that is always a possibility. But if a proven straightedge says it is flat across all axes, then it's flat and good to go.

Photos can be deceiving , I can't tell what the surface is like from the pix and judging stones by photos is always sketchy anyway. Sometimes really fine Arks look like total arse until the surface is cleaned up. Sometimes they show up looking really nice though. You never know.
Get some steel on it, see what it does. You might like it the way it is. I usually proof unknown Arks with some mid-tier cutlery first, then a few test razors.

 

[bmiller3230]

This is a common but often unreliable method of gauging flatness. The grids can and do often wear off long before actual flatness is achieved. Sometimes, just to see how far 'out' things are, I start off with a grid to see where I am at. I use the straight edge as the final say when I am done. Arks can be a pita in this regard. Some go easier than others though - had a smaller Translucent recently that I was able to get dead-flat relatively easily. So that is always a possibility. But if a proven straightedge says it is flat across all axes, then it's flat and good to go.

Photos can be deceiving , I can't tell what the surface is like from the pix and judging stones by photos is always sketchy anyway. Sometimes really fine Arks look like total arse until the surface is cleaned up. Sometimes they show up looking really nice though. You never know.
Get some steel on it, see what it does. You might like it the way it is. I usually proof unknown Arks with some mid-tier cutlery first, then a few test razors.

I honed a bit with it tonight using water with a drop of dish soap. It felt and sounded like basalt or volcanic glass. The the kind of sound it made when turning the blade and the ring when the spine touched. The surface is like glass. It doesn't at all feel or sound like the ILR which is supposed to be some kind of slate.

 

[bmiller3230]

Surface of that hard black definitely does not look lapped. If you took the picture before lapping... that's why it's easy to lap. That looks like SIC/abrasive powder blasted surface... meaning it's loose and craggy and will be VERY easy to lap... at first... and get progressively harder as you get closer to having it lapped. If that is after lapping... stop using that lapping stone... it's roughing up the surface, not lapping it. Get either wet/dry and a flat surface or a diamond plate.

That was before lapping

 

[bmiller3230]

Tried sending you a PM but I don't know if you have it turned off or if it's because you limit who can see your profile.

Anywho, how's the edge off of the maybe Ark?

I can't send PM's to people either. Maybe there is a required number of posts to allow that? I tried it tonight. I have one of my favorite razors that in a moment of inattention while stropping, cut deep into my horse hide strop and needed re-honing. So, I decided to do it on these stones.

I started on the coticule, hoping that was all that was needed. I tried the Dilucot method with a thick slurry and progressively thinning to just water. But I was not satisfied with the keenness of the edge. I'm new to coticules, so that is probably my technique. This one seems harder than I was expecting and seems to be a slower cutter than my synths, but I still need to get used to these rocks and learn their qualities to get the best out of them. I'd say I got the edge to where my Norton 8K would take it.

So, I decided to try finishing with the Ark. I'd say 50 X-strokes later and several stroppings later had it where I wanted it as far as tree-topping, the tomato test, and dry shaving.

I haven't shaved with it yet, but will later this evening or in the morning. I'm due for one.

 

[Gamma]

That was before lapping

I think Ian is referring to the pic where the grid lines are still showing in the corner, that appears to be 'post lapping' , no?
That surface does look 'unfinished' to me, but maybe it is the pic.
Arks don't usually feel like slate.
Dunston stone, which is slate, doesn't feel like typical slate either.
Some Basalt can feel like slate.

You mentioned Basalt and volcanic glass in the same sentence, did you mean basanite?
Seeing them referenced in a honing context is uncommon.