Black Arkansas "primitive" Happy B-day to me!!!

[Dilbone]

No slurry on the coticule...just water and very light pressure.

The shave test seemed ok until I got to ATG on my neck/under jaw. No good.

I'm not sure what I have to do to get a decent edge off this but man I'm growing weary....

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[kelbro]

Well, my experience with the black arkies and translucents is that a freshly lapped surface produces the sharpness/keenness and the burnished side only polishes the scratches away. You have two stones there. A finisher and a polisher.

 

[eKretz]

What are you using to hone - oil or water? I only use oil and always get very nice edges from Arks. Another thing you may want to consider is your pressure level. Often it helps to use a little more initially with Arks, then back it down as you go.

 

[Dilbone]

I've used Smith's honing solution, mineral oil, glycerin/water, and most recently plain water.

The surface just isn't ready yet I don't think. Looking closely at the spine hone wear there are scratches from the arkie that aren't there after the coti. I hit it with another session of burnishing yesterday before trying a few (100) laps on a razor again and the scratches were less noticeable.

I think I'm just not finished with burnishing yet. It looks the most mirror like it ever has but there are still little grainy marks throughout....those are getting fewer and further between as I burnish so I guess I'll keep up with the burnishing.

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[eKretz]

Out of curiosity, what grit did you lap up to?

Edit: NVM, see that it's 2000 wet/dry. I'm kind of surprised you're not there yet. I didn't spend more than a few hours finishing mine after lapping. It might be worth exploring some pressure variations just to be sure.

 

[Dilbone]

I'm going to do one more round of burnishing with the soap and water before I hit it with the razor again. Here's a close up of the graininess.

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[Dilbone]

I just did another 15min session with dish soap and water but I feel like I'm at a point of diminishing returns.
Should the entire surface be glass like or is it normal to be grainy though highly reflective?

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[C FrankC]

I have a primitive from Dan's, looks a lot like yours did before making two out of it. I took mine beyond 2K W/D and used some .5 diamond spray on it. Don't really think that was necessary but what I found very useful was to burnish with a bar of high speed tool steel(8"X1"X.5") using quite a bit of pressure.
A large chisel could be used in the same way, pressure was my friend in this final stage and a hard chisel or bar of tool steel allowed the use of heavy pressure and was easy on the hands.
You might try this on yours with just water, mine got a lot smoother after this treatment.
These primitives are a boatload of work but so worth it in the end.
Hang in there I think you are very close.

 

[eKretz]

I just did another 15min session with dish soap and water but I feel like I'm at a point of diminishing returns.
Should the entire surface be glass like or is it normal to be grainy though highly reflective?

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Looking at the closer up picture I think you have some remaining "grain" or coarser scratches from the earlier lapping - you might not have spent enough time lapping those out at the finer grit. More burnishing might make it okay but I would go back and work those out I think.

A burnishing trick I use occasionally is to use a piece of flat ground tungsten carbide for burnishing. It's WAY harder than the abrasive in the stone and will not go out of flat no matter how much burnishing you do. That stuff burnishes natural stones VERY quickly.

Here are a few shots of my translucent black Ark that I mentioned earlier - the stone is dry in these with no oil or water on the surface:

 

[Dilbone]

I have been looking at hones again and whenever I get the itch to get a hone I remember my poor black arkie and that I still haven't gotten in worked out.
After bidding on and not winning a nice coti last week I decided this weekend that I would get my primitive back out and see if there was anything I could do to make it work.
I got out my norton 8k and used it for quite a while and it knocked most of the burnishing off that had already been done and I was hoping I would have a smoother surface then to work with. I decided I would just go back to burnishing it and see if it just needed more time. Just as I felt like I was getting somewhere and switched to oil from water I noticed I actually scratched the stone pretty well with the Gold Dollar razor I was using to burnish it. I was so angry at myself for using too much pressure and honestly I'm still not sure how it even happened. It was dead straight down the middle of the stone. I should have taken pics but I was too disgusted with myself.
I started with 800grit W/D paper on a marble tile. It was doing very little and the scratches weren't going anywhere so after 2 sheets of that I gave up.

I was doing some searching and came across Krodor's account of readying his black arkie for use. He said at one point he used a barbers hone to finally get some progress on his after taking it to the belt sander.

It dawned on me that I should try my King 1k and see if the slurry of that stone would maybe help. I'll be darned if that King made some remarkable progress. the scratches were gone in less than an hour and I continued to work on it here and there to get some other surface imperfections and make sure the scratches were good and gone. It is the most uniform and consistent the surface has ever looked. All the hours and sore arms and sheets of W/D paper in the trash and all I needed was a couple of hours on the King 1k.

I then did a short time on the King 6k and went on to burnishing.

I really should have gotten pics of all of this but I was just happy to be seeing some progress. I'll have to snap some pics tonight of where it is now. I think I may actually be able to hone with this thing within a week. Woo hoo

 

[Dilbone]

Here are some pics of where it is now compared to where it was when I first cut this larger stone in half. I know some of you will shudder at the thought of me cutting this 4"x7" primitive in "half" but I'm good with it.

On the left is where it is now. The old piece shows some of the "texture" I was dealing with that I was able to get rid of with the King 1k. The piece I've been working on didn't look as bad as the other when I started this weekend. I had spent several hours this summer with W/D paper that barely made a dent but it was at least a dent.

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[kelbro]

Looking good!

 

[Dilbone]

Looking good!

I wish I could tell when it's ready!!

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[Dilbone]

This is what it looks like to my eye directly under the lights only clearer after another 20 minutes of burnishing under water. It's terrible to get a decent pic of the reflection straight on

And another

Here it is after another 10 minutes of burnishing (I've been trying to do 10 minutes at a time)

I'd like to try it again but I don't want to ruin the edge I just got back again on the razor I've been experimenting with. Oh well.

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[eKretz]

I think you are there.

 

[kelbro]

Agree with eKretz. Law of diminishing returns is at work here...

 

[Dilbone]

I think you are there.

Agree with eKretz. Law of diminishing returns is at work here...

I ended up doing some laps on it and it seemed to kill the edge. No shave test with it because it wasn't topping any hairs at all on the FOTF test or was very weak at best while straight off the coti it plows through arm and leg hair floating well above skin.

Since then I had a naniwa 12000 arrive and tried it out. The edge was very similar after the Nani as it was after the arki. Not topping hairs very well compared to off the coti.
I decided to shave with it anyway and it seemed to be a sharper edge than off the coti.

Does that seem normal at all? Does the coti leave it with some kind of saw tooth edge that catches hairs better but isn't necessarily any sharper?

I'm gonna do some experimenting with the arki again and do a shave test with it and see if maybe it is sharp enough, but now I've got the nani to figure out too.

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[eKretz]

Are you stropping before trying the test? That is not something that happens in my experience - I can only suggest trying the shave test anyway and see what you've actually got.

 

[Dilbone]

Just a few laps on my pant leg or forearm for pretest stropping


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[kelbro]

I think that you have gone above and beyond on the effort with that stone and it's just not going to happen for you. It seems to be cursed since you cut it in half and the Xi escaped from it. Novaculite is like that, you know.

Send the lousy rock(s) to me and I will dispose of it properly when I drive through Washita in a couple of weeks.