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Testing Natural Hones & Eval/Determination

I’ve been spending some time lately trying to more objectively evaluate some natural hones I’ve acquired over the last few months and years. some have explicitly been cut as whetstones, a couple are random stones just big enough to hone on.

I may have asked these questions before, i cant remember if i asked them the same way or even the same thing since i didnt have certain stone experiences before.

I’ve watched a bunch of vids on surface prep, particle size, shape, distribution, substrate, read the diy hone and regular surface prep/finishing threads.

i see some people prep a surface at 120, some at 300, some at 600, some at 1000 and some to ~3000.

I think I also understand there is an interplay of material “issues”, as in at times the honing surface may more be affected more by the cutting of the lapping medium and the base stone hardness and then as the lapping becomes finer the base stones inherent qualities would become more pronounced. and sometimes balance is found by conditioning a surface by either toning it down (steel on ark) or refreshing it (deglazing for example). I think i get its about size, distribution and exposure.

i’m trying to understand how someone decides they will stop at 300 grit for lapping versus 600 or even use 2000 high polishing. (Especially when they are using a “low” mag loupe). Is it just guess/check and shave test subjective experience? Are they honing to a known space (like 12K for example) and then working backwards or forwards, until it obviously regresses an edge? Or doesnt do anything after a certain number of laps? and just spending days testing it?

are folks primarily looking for how low a surface prep cuts before moving it turns to polishing? Or is it where you are looking for it to cut a bevel, act as an intermediate, or to finish?

for example, a question i have is if you overprep a modern hard ark or it glazes over and it’s slowly slowly polishing, would you consider it a finisher? Is it much slower than a surgical black? or would you keep lowering the surface prep until it cuts and you see swarf? Do you need to see swarf on your finishers?

I’ve been working on a 2 semi-random chalcedony pieces (not the ancient ocean jasper) and had them really highly polished finish, and they seemed to be improve a 10K edge but then i recently saw a comment where they talked about surface prep at 300. And it got me paranoid about consistency and objectivity.

so i guess I’m really interested in your test and evaluation process.

is there and obvious tell about what a stone will give up to you as far as capacity and where it works best?

is testing first done for you on a chisel or kiridashi?
 
This may be slightly off topic and maybe not the kind of answer you are looking for.
But I usually use my ark with water, when it starts to bead on the surface I rub a soft nagura(they clear embedded dwarf good enough on jnats so why not arks?) on it and it gets its cutting power back and stops beading.
I have not tested different surface grits so much, but I am interested in hearing this aswell.
 
But I usually use my ark with water, when it starts to bead on the surface I rub a soft nagura(they clear embedded dwarf good enough on jnats so why not arks?) on it and it gets its cutting power back and stops beading.

Yeah, not so much what i am aiming for, but good add. This is for finishing? SB or transluscent?
 
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Yeah, not so much what i am aiming for, but good add. This is for finishing? SB or transluscent?
It's a SB. I went the sandpaper route, not doing it again 😂
I went maybe up to a 1000 grit then I use nagura stones for refreshment.
Have used my coticule to rub on the ark aswell to smooth the coticule and refresh the ark. Either seems to work alright.
 
You have a lot of different questions tied up in there GlobalDev but one theme. I’ll try and give you my opinion and what I do, but I am sure everyone is a little different.

I have no formula and it is just about using the stone and what works. If something is too coarse you will feel, see and know it. If something feels like it is finished so fine the stone can’t work, you will feel, see and know it. I use a 400 and 1000 plates for flattening and so 95% of the time it will be one of those just because that is what I use. For non-novaculite, I don’t think it matters that much with most stones. If you leave it too coarse it is like a rough file and will cut coarsely until those ridges are knocked down by honing. But anywhere finer than that and the properties of the stone, particles, and release all should take over. 400, 600, 1000, probably doesn’t matter to me on most stones.

Novaculite is not about grit as you know, so a little different. Finish, pressure, burnish/loading all affect both performance and outcome. You can manipulate each of these factors in the equation to suit you. Want a fast cutter? Finish coarsely, use with strong pressure, and be sure to refinish stone often to remove any burnishing and keep coarse. Complete opposite end of the spectrum where you want a fine finish? Finish the stone to 2000 grit W/D, burnish with a wide soft-steel blade, and use with light touch. Do that last one well enough and it may never even remove steel. You can manipulate all of those to affect speed and cutting of novaculite.

So my answer is do what is obvious to you. You have a chalcedony that won’t cut, try roughing it up some and see what happens. Have a jasper that is too coarse, take it down a notch or two with some W/D and see if that changes anything. You may get a change and may not. Sometimes you have to keep refinishing, often the stone dominates. Novaculite is a little different and is why some people prep both sides of a stone differently effectively making a dual speed hone. But there is a limit to prepping. You can’t prep a poor stone into working well. A glazy stone will glaze, coarse stones are just coarse, etc. Prep is more like fine tuning and some stones can be tuned and others scoff at your attempt to manipulate them.

Only true test is time on the rocks and experimentation. Part of the fun though, right?
 
I’ve been spending some time lately trying to more objectively evaluate some natural hones I’ve acquired over the last few months and years. some have explicitly been cut as whetstones, a couple are random stones just big enough to hone on.

I may have asked these questions before, i cant remember if i asked them the same way or even the same thing since i didnt have certain stone experiences before.

I’ve watched a bunch of vids on surface prep, particle size, shape, distribution, substrate, read the diy hone and regular surface prep/finishing threads.

i see some people prep a surface at 120, some at 300, some at 600, some at 1000 and some to ~3000.

I think I also understand there is an interplay of material “issues”, as in at times the honing surface may more be affected more by the cutting of the lapping medium and the base stone hardness and then as the lapping becomes finer the base stones inherent qualities would become more pronounced. and sometimes balance is found by conditioning a surface by either toning it down (steel on ark) or refreshing it (deglazing for example). I think i get its about size, distribution and exposure.

i’m trying to understand how someone decides they will stop at 300 grit for lapping versus 600 or even use 2000 high polishing. (Especially when they are using a “low” mag loupe). Is it just guess/check and shave test subjective experience? Are they honing to a known space (like 12K for example) and then working backwards or forwards, until it obviously regresses an edge? Or doesnt do anything after a certain number of laps? and just spending days testing it?

are folks primarily looking for how low a surface prep cuts before moving it turns to polishing? Or is it where you are looking for it to cut a bevel, act as an intermediate, or to finish?

for example, a question i have is if you overprep a modern hard ark or it glazes over and it’s slowly slowly polishing, would you consider it a finisher? Is it much slower than a surgical black? or would you keep lowering the surface prep until it cuts and you see swarf? Do you need to see swarf on your finishers?

I’ve been working on a 2 semi-random chalcedony pieces (not the ancient ocean jasper) and had them really highly polished finish, and they seemed to be improve a 10K edge but then i recently saw a comment where they talked about surface prep at 300. And it got me paranoid about consistency and objectivity.

so i guess I’m really interested in your test and evaluation process.

is there and obvious tell about what a stone will give up to you as far as capacity and where it works best?

is testing first done for you on a chisel or kiridashi?
I consider flattening and lapping to be two separate processes. Lapping is to flattening as honing is to sharpening.
 
I consider flattening and lapping to be two separate processes. Lapping is to flattening as honing is to sharpening.

i, too, consider them to be different, i think the length of the post and intersection of questions/thoughts while typing it out on a mobile phone gets in the way of better writing and clarity for me.
 
I haven't been putting in the work I would like to recently but am experimenting with scratched, furrowed or corrugated surface. Not sure what to call it. I got there with a piece of jasper that bumped edges pretty well only to discover I hadn't removed all the saw marks. Not sure there is really a benefit but not ruling it out.

And then I come across this gentleman on youtube doing similar to his ark.


I have not tried this with arks but probably will at some point. I suspect it may just be reducing surface contact and speeding up the stone or perhaps cutting down on suction also. I really don't know.


Throw in lubrication, pressure, technique and all kinds of results may be possible. Never mind all the cool rocks to play with.
 
i’m trying to understand how someone decides they will stop at 300 grit for lapping versus 600 or even use 2000 high polishing.

Typically, if a stone is on the soft side, most feel there is no need to dress it fine because it will become smoother through use.
This is especially true if you are using any form of slurry with the stone.
Through my own experience (without using slurry) but using just the hone with water I found a better result occurs when dressing to a finer state (with an Escher) - at least initially, that is, it may become as fine through use with just water but it may take some time.
As these don't typically "clog" I always dress to the finer side. You will not get a lesser result doing so.
It may make a particular type stone somewhat slower but it will still be the finest it can give IMO.
 
Through my own experience (without using slurry) but using just the hone with water I found a better result occurs when dressing to a finer state (with an Escher) - at least initially, that is, it may become as fine through use with just water but it may take some time.
As these don't typically "clog" I always dress to the finer side.

whats the finer side? 600,1K or 3K?
 
I have taken an Escher to 1k as I use it with water only.
It will eventually smooth out even just with water but why not start with a fine surface.
In my tests years ago if it was dressed to 400 Atoma or similar and used with water it would not produce as nice of an edge as dressed to 1k.
 
I have taken an Escher to 1k as I use it with water only.
It will eventually smooth out even just with water but why not start with a fine surface.
In my tests years ago if it was dressed to 400 Atoma or similar and used with water it would not produce as nice of an edge as dressed to 1k.
I’ve never used any other than 1k w/d on my stones, happy with results, never tried something else and likely never will...
Aren't you guys using rub stones with your Thuringians? I would expect the rub stone to make the surface prep somewhat mute.
 
"Through my own experience (without using slurry) but using just the hone with water I found a better result occurs when dressing to a finer state (with an Escher) "

No, never.
If I did then it would not matter.
 
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