Getting serious about a Black Arkansas stone

[duke762]

Can you elaborate on your pockmarking issue? I may have had something similar happen once.

I'd like to add my theory on the pockmarking you mentioned. Loose grit, as used by the manufacturer and by us, rolls around under the stone and actually flattens it by fracturing out little pockmarks. This is why loose SC can flatten a hone quickly but not finish it smooth. Fixed grit such as W/D sand paper does not roll and finishes the surface through conventional abrasive action. Think how sand paper works on wood. I was once driven to try and remove every little one until I had a perfect surface. Now, if the surface is flat and smooth enough, I just view them as little oil reservoirs.

I’m torn between water or oil on the arks though.

The Black/Trans family can go back and forth between water and oil very easily. Some detergent on the oilstone Ark and it's a water stone. Very versatile in that respect. Softer Arks...your pretty well locked into some sort of oil. I happen to dislike water as a honing fluid. It's a phobia thing, not a performance issue. I do use water on my synthetic bevel setter and whine the whole time, but the results are great! An oil with a water like consistency works best for me on Black/Trans. Choose your flavor. My very favorite thing is WD 40. Try everything and see what you like and what works best for you.

Happy to see more Arkholics in the making!

 

[life2short1971]

I’d like to see some pics closeup of the pockmarking on stones that are victim to it please.

 

[Friedramen]

Here's a trans from nwc with some. This is an 8x3x1 which surprisingly came pretty flat on one side but came with some deep pock marks on both sides. On the flatter side I lapped with sic up to 800 iirc but there are still visible pock marks. I think I would use up my whole supply of sic if I tried to eradicate them completely. So far they haven't had an any ill effect on a razor. Lovely stone otherwise.

The last 2 pics are from the side I hone on.

 

[life2short1971]

Here's a trans from nwc with some. This is an 8x3x1 which surprisingly came pretty flat on one side but came with some deep pock marks on both sides. On the flatter side I lapped with sic up to 800 iirc but there are still visible pock marks. I think I would use up my whole supply of sic if I tried to eradicate them completely. So far they haven't had an any ill effect on a razor. Lovely stone otherwise.

The last 2 pics are from the side I hone on.

I can see air bubbles which as the stone is lapped they rise to the surface and get popped. they will show up eventually no matter how its lapped but maybe SiC opens them faster. I'm sure the hardness in the stone plays a part in how fast they appear also. I would also think the stray chip that gets freed as the stone is used may cause the occasional rogue scratch as well.
Thank you for showing your stone.

 

[Alum of Potash]

I've ran in to the pockmarks but I think they are caused by the stone itself rather than the SIC. Some of the translucent and blacks have what looks like little tiny bubbles in them and when you lap into them they leave those marks. I just finished up lapping a 12x3x1 Norton Black on 400x SIC and it's smooth as glass-no marks at all.

No reply from the source of the remark, and I recognize that this is OT from the original post, but thanks for your comment David. The reason I ask has to do with a "true hard" Arkansas (more like a translucent) that I picked up from Dan's a few years back. On the surface, there are a few holes filled with what looks like a black pore. I have yet to really succeed with this surface and have been thinking that it might be caused by some coarse particles of SiC lodged within from the original lapping session.

 

[duke762]

Bought a Dan's plain vanilla hard a few years back. So much lapping debris was trapped in it's surface, it changed colors quite a bit after I lapped it out.

 

[Alum of Potash]

I'd like to add my theory on the pockmarking you mentioned. Loose grit, as used by the manufacturer and by us, rolls around under the stone and actually flattens it by fracturing out little pockmarks. This is why loose SC can flatten a hone quickly but not finish it smooth. Fixed grit such as W/D sand paper does not roll and finishes the surface through conventional abrasive action. Think how sand paper works on wood. I was once driven to try and remove every little one until I had a perfect surface. Now, if the surface is flat and smooth enough, I just view them as little oil reservoirs.

Thank you for your remarks. This was a few years back, but as I recall, I lapped the stone in the early stages with loose SIC up to around 320x, followed by w/d sandpaper, 600x and 1000x. My concern is that if a lodged particle is there, then it maybe something like 120x, wreaking havoc. If not, then maybe it's a peppering of black hard Arkansas. It appeared to be causing some chipping then, but maybe it had to do with my technique at the time.

My understanding is that Dan's lapping is done with an enormous rotating 120x abrasive disc, rather than loose particles, or so they have told me. The fresh discs are used to lap the soft Arkansas line and the worn discs are used to lap the hard Arkansas line.

 

[Alum of Potash]

Here's a trans from nwc with some. This is an 8x3x1 which surprisingly came pretty flat on one side but came with some deep pock marks on both sides. On the flatter side I lapped with sic up to 800 iirc but there are still visible pock marks. I think I would use up my whole supply of sic if I tried to eradicate them completely. So far they haven't had an any ill effect on a razor. Lovely stone otherwise.

The last 2 pics are from the side I hone on.

I appreciate these shots. Looks pretty similar to the condition I mentioned. Thanks.

 

[SliceOfLife]

The Pockmarking I experienced was distributed across the stone... it was caused by a piece of abrasive sticking to the stone and moving with it rather than cutting it... basically gouging out its own little cave to live in, then another piece would hop into the cave and push the first one further up, etc. This happened all across the stone. It's not a big problem with the higher grits, but I was using 60-100 grit stuff... so these were BIG holes all across the surface that I had to spend quite a bit of time on a DMT to sand past. It mostly was a problem with Charnleys.

 

[Toro Blanco]

I remember reading a old report on air bubbles in Arkies. It stated that it was most common in washitas and Rosy Reds had them the most.

 

[HVenture138]

Well this arrived today

it’s came dead flat and lapped pretty smooth. I sent Dans an email asking what grit it was lapped to. Anybody wanna wager a guess as to what they’ll say? I think I’m gonnatake a gold dollar as far as I can with the surface like this

 

[SliceOfLife]

I remember reading a old report on air bubbles in Arkies. It stated that it was most common in washitas and Rosy Reds had them the most.

Soft Washita in general (I think all Rosy Reds are Soft, but I'm not certain), are quite porous. I wouldn't really call them air bubbles though... They're pretty regular. I suspect it's from a mineral being in the matrix that was very slightly water soluble and washed away over millions of years.

The really dark, coarse, translucent washita are the easiest to see this in. They're fun stones... Look like a hard ark dressed up as a washita... act almost exactly like a turkey stone.


@HVenture138 Wild guess, but I'm gonna say 600-1200 from the looks of it. Beautiful stone. I certainly wouldn't bother polishing it further.

 

[HVenture138]

@HVenture138 Wild guess, but I'm gonna say 600-1200 from the looks of it. Beautiful stone. I certainly wouldn't bother polishing it further.
[/QUOTE]

“All of our stones are hand cut and hand finished on a large lapidary wheel with somewhere around a 90 grit silicon carbide that has been recycled to a little bit finer that is ran on the wheels that we finish the Black Arkansas (ultra fine) and Translucent Arkansas (extra fine) stones. When you start using the stone – the natural texture of the stone should appear. The grit of the Black Arkansas stone is around 1,200+. It is the finest stone that we manufacture. It help you to achieve a keen razor sharp edge on your blades. You should be able to start using the stone right out of the box. I have been receiving a lot of inquiry about lapping the stones – we do not feel that it is necessary. The unique make up of the material will help to achieve a keen razor sharp edge.”

No pockmarks at all, very smooth.

 

[Toro Blanco]

I was refering to the one friedman posted that looks more like su on jnats. I have one with a bid one and have seen them in other peoples stones too. It could be erosion but some look more su like, if you will.

This red one is my example. I have had over two dozen washitas and have only found it on two.

 

[David]

I remember reading a old report on air bubbles in Arkies. It stated that it was most common in washitas and Rosy Reds had them the most.

Here's a pic of a Rosy Red on top and a Lily White Washita on the bottom. You can tell the RR has a more open grain and is softer than the LW. As far as the bubbles, I don't recall ever seeing them on a LW, but I do have at least one number 1 grade that has large su like bubbles on the surface.

 

[Bowmaker]

In some old literature I have read (can't remember where)they talked about "sand hollows". I have had stones that would wreck an edge, still do have one. They seem to be more prevalent in the multicolored stones around the color changes that also signals a change in texture.
I know color doesn't matter and all that stuff, but I sure have come across stones I didn't like with uneven feedback ect that sure did correspond to a change in color. YMMV

 

[Toro Blanco]

I know what you mean Bow, those were the lower grades. Fast cutting and even feeling surface was something I quickly learned to look for in a washita.

I forget what they called them( orb things, lol)it's been so long. I was referring to the sand holes like this one.

This was pin size but the more I used it the bigger it got. Now getting to the bottom.
Ll they cut it out, RR has been so much rarer it was overlooked was a response from a very knowlegeable collector but he could not prove. Said he got it from the manager of norton right before they changed a lot of their operations. This was 5-6 years ago so I could be off a little.

 

[Alum of Potash]

I remember reading a old report on air bubbles in Arkies. It stated that it was most common in washitas and Rosy Reds had them the most.

I've seen Washitas or soft Arkansas with "air bubbles." But what seemed lodged within seemed reduced and of natural occurrence.

 

[Alum of Potash]

The Pockmarking I experienced was distributed across the stone... it was caused by a piece of abrasive sticking to the stone and moving with it rather than cutting it... basically gouging out its own little cave to live in, then another piece would hop into the cave and push the first one further up, etc. This happened all across the stone. It's not a big problem with the higher grits, but I was using 60-100 grit stuff... so these were BIG holes all across the surface that I had to spend quite a bit of time on a DMT to sand past. It mostly was a problem with Charnleys.

Interesting. Thanks for the reply. I do have a Charnley with a similar "blackhead" situation come to think of it. And I pretty much lapped it in the same way. But the lodging there has never been a problem. Perhaps the hole is larger and it is below the honing surface. Coarsest loose SiC grit I have used here is 120x.

 

[Alum of Potash]

I think we need a thread on the "pockmarking" issue. Or maybe SoL started one a while back?