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My Journey Into Black Arkansas

rbscebu

Girls call me Makaluod
For many months I have coveted a black Arkansas whetstone. last week a knife bloke in Brisbane offered to sell me his 200mm x 50mm x 12mm (8" x 2" x ½") black Arkansas for a price I couldn't refuse. His reason for selling was that it was just too hard for him to use on his knives.

My black Arkansas arrived in this morning's mail.

Blk Ark as received.JPG

Fig. 1 - As Received
It came without a timber case (to save postage) but did include a black silicon rubber base support. I didn't mind not having a case as I intend to make a western red cedar case for it, to match my other natural stone cases. The surface shown was noticeably smooth except for the ends and along one side. I an guessing this was the surface he used to try and sharpen his knives.

After inspecting it all over, I decided to measure the stones SG. Volume was measured three times using the water displacement method and gave an average reading of 129,326mm³. The stone has a measured mass of 352g ±2g. This gives an SG of 2.72, surprisingly dense.

I had a few sheets of 100grit W&D, so got out my polished granite slab and got to work. About an hour and six W&D sheets ($18) later, the top side was lapped reasonably flat - removing the marker pen grid in about 10 laps. There are still two 8mm triangular areas at diagonally opposite corners that show marker pen. I am not bothered about those two small areas for now.

I then broke the edges (12) of the stone all round with some of the worn W&D. Realising that I needed to be able to differentiate between each side of the stone, I ran a white paint marker around the edge of the surface I had just roughly lapped. Here is my black Ark now:

Blk Ark marked.JPG

Fig. 2 - Lapped & Marked

As suggested to me by @Tomo, I have some 160 grit SiC on order that should be delivered within a day or two. Once I get that, I will finish the initial lapping of both sides.
 
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rbscebu

Girls call me Makaluod
Do you know where the seller originally sourced the stone from, by any chance?
No, although I expect it was originally from the USA. I didn't know from whom in the USA. I didn't ask him as I believe that it had no bearing on the quality of the stone.

Dan's are highly regarded mainly because he takes the trouble to properly lap them flat. As mine was used, I expected that I would need to lap it before use.
 

Legion

Staff member
No, although I expect it was originally from the USA. I didn't know from whom in the USA. I didn't ask him as I believe that it had no bearing on the quality of the stone.

Dan's are highly regarded mainly because he takes the trouble to properly lap them flat. As mine was used, I expected that I would need to lap it before use.
Yeah. There are some different stones sold as black arks, from a few different sellers in the US. I think Dans even has a couple of types. I was just trying to get a read on the type of stone because it is really hard to tell from pictures sometimes.
 

rbscebu

Girls call me Makaluod
Yeah. There are some different stones sold as black arks, from a few different sellers in the US. I think Dans even has a couple of types. I was just trying to get a read on the type of stone because it is really hard to tell from pictures sometimes.
I agree. Knowing the dimensions of the stone, before buying I asked the vendor how much it weighed. He told me and I cancelled that it had an SG of about 2.7. (I thought that SG was rather high but it has since been proven correct.) That and the pics he provided was enough to get me to commit.

So far I am very happy with what I received. Of course the real test will come with shaving.
 

Legion

Staff member
I agree. Knowing the dimensions of the stone, before buying I asked the vendor how much it weighed. He told me and I cancelled that it had an SG of about 2.7. (I thought that SG was rather high but it has since been proven correct.) That and the pics he provided was enough to get me to commit.

So far I am very happy with what I received. Of course the real test will come with shaving.
Yep. The proof is in the pudding.
 
The problem with not flattening an Ark completely is most of your stone is smooth but parts are not. As the stone wears or your stroke alters, the edge comes in contact with the “rough spots” and can spoil the edge. The stone gets the blame, but it could just be stone prep, and the “stone” is just fine.

So, how much contact does it take to muff an edge? Not much. And if you are new to Ark finishing a razor, you just added a ton of variables to your process.

Two things that affect Ark finish on a razor, 1. the quality of the stone, 2. stone preparation.

If you are lapping, you need an aggressive abrasive, 60 grit loose Silicone Carbide or 60 girt Diamond. Diamond is twice as fast as loose Silicone Carbide. Wet and Dry cut the slowest and wears out fastest. Wet and Dry is great for altering a stone face ONCE the stone face is flat and completely smooth.

Remember to flatten a stone, you must remove all the flat part of the stone to the level of the lowest part of the stone. With 100 grit Wet and Dry you are conditioning the already flat part and not removing much stone.

A Coarse Silicone Carbide stone and 60 grit loose Diamond powder is the fastest way to lap a new hard Ark flat and smooth.

The trick to all honing is to simplify, and eliminate as many variables as possible, so you can pinpoint problem when they occur.
 
Nice looking stone R!

You're right it is very heavy for a black ark - weirdly so. Though I'm sure will still be grand, perhaps just a little less pure than some. And you'll only ever need to flatten it once toom which is nice!

(If it wasn't flat when you got it then that's not from previous use, it just wasn't flat originally. You can't noticeably dish a black ark from knife sharpening. Prolonged, heavy use for tool sharpening perhaps.)
 

rbscebu

Girls call me Makaluod
....
(If it wasn't flat when you got it then that's not from previous use, it just wasn't flat originally. You can't noticeably dish a black ark from knife sharpening. Prolonged, heavy use for tool sharpening perhaps.)
My initial lapping (all I have done so far) consisted of cross hatching the surface with marker pen and starting on 100 grit W&D - because that is what I had available.

At first nothing was happening to the hatching. Then, without me noticing, it disappeared except at the ends and down one side. More sheets of W&D and more heavy laps gradually removed most of the hatching except for the two small diagonally opposite cornes. By then I was down to my last sheet of W&D so decided to give it a rest untill my SiC powder arrived.

I agree that the stone was probably not dead flat from the "factory". The previous owner also probably used it as received. That would explain the smoother area on one of the stone's faces.

My main concern now is to finish lapping both faces using SiC powder (when it arrives). Then I will use a progression of W&D grits to get to 600 on one face and 1k on the other face. Once that is done, I will start working out what level of conditioning I prefer for each of my different SRs. Luckily I only have about 10 different types of SRs.

W&D is easy to source locally. SiC powder is a bit more difficult. That has to come from Brisbane, over 1,000km away, with limited grits available. Diamond powder costs 5 to 10 times as much as SiC and I need to source that from overseas, taking a month or two to arrive.
 

Legion

Staff member
My initial lapping (all I have done so far) consisted of cross hatching the surface with marker pen and starting on 100 grit W&D - because that is what I had available.

At first nothing was happening to the hatching. Then, without me noticing, it disappeared except at the ends and down one side. More sheets of W&D and more heavy laps gradually removed most of the hatching except for the two small diagonally opposite cornes. By then I was down to my last sheet of W&D so decided to give it a rest untill my SiC powder arrived.

I agree that the stone was probably not dead flat from the "factory". The previous owner also probably used it as received. That would explain the smoother area on one of the stone's faces.

My main concern now is to finish lapping both faces using SiC powder (when it arrives). Then I will use a progression of W&D grits to get to 600 on one face and 1k on the other face. Once that is done, I will start working out what level of conditioning I prefer for each of my different SRs. Luckily I only have about 10 different types of SRs.

W&D is easy to source locally. SiC powder is a bit more difficult. That has to come from Brisbane, over 1,000km away, with limited grits available. Diamond powder costs 5 to 10 times as much as SiC and I need to source that from overseas, taking a month or two to arrive.
For future purchases you can get SIC on Aliexpress.
 
I have similar problems geting SIC - i have used wet and dry, it just means i go through lots of sheets. I only have 2 arks (ones was from dan's) and neither needed full lapping for hours. Enjoy, I am relatively new to arks and love the edges they give me
 
my Ark produces as good an edge as I can muster. but I have to present it will really nice edge from the get go, lncluding geometry etc. I dont have the skills or patience to be doing some sort of compensated rolling x thingamajig with torque on the toe on a trans ark. Stricly "perfect" edges make it to my ark.
 
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