Japanese Nagura stone

when i got my full set of naniwas i also brought the the yellow nagura stone to help scrub them clean. In doing so i found my hones wern't feel smooth in honing omtimes a little rough. so i lapped them with dmt c and in honing they are now very smooth and i have to say feel exallant. I found this with my kitiyama which comes with nagura stone that made my hone feel not as smooth in honing so i never used it again. I will clean with palm of hand and srub them up,with dmt. Any one one else come across this ?

The nagura does clean hones up well just the surface is left not as smooth don't no why.

Natural Nagura stonesare not all equal. The grit size will vary just as the natural Jpanese stones do. The same applies to man made nagura stones. The result is a "texture" on the hone surface that may be unpleasant . I finish lapping my hones with a 1000 grit hone. That way I always have the same texture starting point.


Just my $.02,:)

I find dmtc gives a nice smooth hone at least it feel smooth the nagura is not nice. So could i hone my naniwas with 1k norton?

You can but will not make a sense . Use Sandpaper for that purposes(if you want to get 1000grit surface).

I i will stick to my dmtc it gives a quik clean up on synthetics and i should imagine they are reltavly flat.

When I lap my hones I use either sandpaper or a diamond hone but I always finish with a 1K Norton to give me the texture I want.

When I lightly "refresh" ( cleans and flattens between razors) my hones I use only the 1K Norton.

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Originally Posted by hi_bud_gl

You can but will not make a sense . Use Sandpaper for that purposes(if you want to get 1000grit surface).

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when you say something like this; the Why is always needed. :)

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Originally Posted by randydance062449

When I lap my hones I use either sandpaper or a diamond hone but I always finish with a 1K Norton to give me the texture I want.

When I lightly "refresh" ( cleans and flattens between razors) my hones I use only the 1K Norton.

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I will have to try norton 1k does it leave a smoother surface than dmtc?

Why is a smooth beyond 325 grit surface needed, as well, for what grit stone? (keeping separate synthetic from high grade natural)

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Originally Posted by kevint

Why is a smooth beyond 325 grit surface needed, as well, for what grit stone? (keeping separate synthetic from high grade natural)

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don't mean to be rude but don't quite under stand what your asking better explanation may help on both your posts

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Originally Posted by gary haywood

don't mean to be rude but don't quite under stand what your asking better explanation may help on both your posts

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I imagine 325 gives good surface on your hones surface and laps fairly quik whilst the 1000 will smooth surface even better i'm just presuming but like i say 325dmtc works extremly well for me.

I was asking why are the surface scratches on a hone given such attention.

I have seen techniques that include progressive lapping and such to get to an apparently magical 1000 grit. If fineness is so important why is that fine enough?

Also do people treat coarser stones differently- finer lapping for finer stones?

Finally why would one consider sandpaper superior to using a flat stone?

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Originally Posted by kevint

Finally why would one consider sandpaper superior to using a flat stone?

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i can answer to this question . i said sandpaper because it is cheaper and available to most people. if you have norton go head use Norton. i never go until 1k grit i have gone 600 sandpaper that is it. i may need to try 1k maybe i will like the result.hope this clear 's my part.

I would use wet and dry sand paper i would use p600 on say 4k 8k 121 k ,coticules or my 325 as for a 1k i'd use 325 or 220 wet and dry. but to be onest 325 dmt is fine on every thing i did have norton flatterning stone it was good but the hone surface wheather it be 1k or 8k 4k etc was'nt as nice as the 325 dmt left i think most people on srp use dmtc it does'nt need lapping and its quik and easy it cleans your hones up in seconds synthetic that is. I just felt when honing i could feel the differance and i got realy good edges .

sand paper is cheaper but in the long run a dmtc would pay for its self./

Only don't use dmt 1200 and higher for lapping purposes. diamonds will get loose very fast.hope this helps.

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Originally Posted by gary haywood

I will have to try norton 1k does it leave a smoother surface than dmtc?

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I have not used a DMT 8C, which I understand to be a 325 grit, but I have used a EZ Lap 400 grit diamond hone.
I find the 1000 grit texture to be to my liking, it is nothing more than a personal preference. Some people like a 325 grit texture to start! Try both and see which you prefer.

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Originally Posted by kevint

Finally why would one consider sandpaper superior to using a flat stone?

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Sandpaper has more abrasive grains per square inch so it is faster plus you don't have to lap it!:)

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Originally Posted by gary haywood

So could i hone my naniwas with 1k norton?

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Why not? Just make sure the Norton 1000 is flat when you start.

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Originally Posted by kevint

Why is a smooth beyond 325 grit surface needed, as well, for what grit stone? (keeping separate synthetic from high grade natural)

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Smooth beyond 325 is not needed IMHO. It i just a personal preference. As you know the primary purpose of lapping is to flatten a hone. The other major benefit is to removed any embedded swarf ( junk) left over from previous honing sessions. Along the way you find that it is nice to start from the same texture each time. Which texture and on which hone is a personal decision.

Just my $.02,:)

what about the smooth surface, steel plasticity can-o-worm you opened over in another thread?

kevint,
Steel plasticity can of worms? Can you cite that thread for me? I'd like to (re?) read that one. However plastic steel may be, I'm not sure I see the connection of that to the surface fineness or surface "feel" of a hone. Unless you're worried about the plasticity of steel being sufficient to allow it to flow into the ruts left by lapping the hone on a device with a coarser grit rating than the hone itself. :shrug:

OK, some time ago when Robert Williams had his website there was a post commented on by Robert, Mike Blue and MParker. Part of the thread discussed the plasticity of steel and honing. This was a surprise to me since I had never heard of steel having plasticity.

At what level this comes into effect I do not know and I have not brought it up here simply because it would be so technical that I doubt we can make use of it.

OK , that's the can of worms.:)

AHA! Thank you Randy.

Now those of us with screwdrivers can begin to pry off the lid and delve into the mysteries of...



plastic?? :aargh:

http://straightrazorpalace.com/advan...mentary-3.html

right there near r the end than start.

Besides the issue of better tactile feedback ("feel") being provided by a smoothed out polishing stone is the fact that a stone will cut more efficiently in this state. A smooth stone presents more of it's surface (area) to the tool being sharpened thus cuts faster and often provides better results in edge quality than what can be achieved by using the same stone in a rougher state.

FWIW - I use a DMT Dia-Sharp D8XX for all my stone flattening/lapping. For polishing stones I follow that with a D8C and then I further smooth with a synthetic nagura, my favorite being a Naniwa 600x (supplied with Choseras).

I find that the most enjoyable surface on my
Nakayama can be had by lapping with a D8C
followed by the use of a Nakayama rubbing
stone. I continue to use the rubbing stone,
which is basically the same as the hone itself,
to refresh the surface between honings.

- Scott

within reason the texture of a bonded abrasive doesn't matter. It will wear down/smooth out with use. This is what I argued with my sedimentary (and as I was corrected, metamorphosed sedimentary) rock. The grit is determined by the cutting particle size, not the texture of the bonding agent.
If you use something solid and hard than steel (jade, quartz, jasper) the texture would matter as the surface itself is doing the cutting.
That being said, in theory you can lap with a 120 grit paper and be just fine. It just leaves scratches. I lap at 120 or 200ish, then quickly (fivish mins of work) work my way up to 1000 grit paper. Just to get rid of cosmetic scratches on my naturals and Swaty's.
my .02

has anyone noticed differences between using natural nagura vs. synthetic?

especially those very soft white ones.

personally i find it very difficult to tell the difference between 400 and 1000 as regards the feel of steel on stone. maybe the difference is constant wash vs slurry acting with the plate. Or sandpaper(hate it) vs plate, or coarse stone vs paper or plate.

jade, quartz jasper must all work the same as any other hone. ultimate smoothness - such as sub-micrometer mirror polish may lead to more of a burnishing effect rather than honing- just making stuff up but its a fact now

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Originally Posted by kevint

jade, quartz jasper must all work the same as any other hone. ultimate smoothness - such as sub-micrometer mirror polish may lead to more of a burnishing effect rather than honing- just making stuff up but its a fact now

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They don't. And won't. A coticule cuts with garnets that are within a certain size range, giving it it's grit. Naniwas, Shaptons, Nortons, all have little pieces of grit that do the work, most of the stone is adhesive to hold that grit in stone form, like grit on a sand paper. The glue breaks down releasing more abrasive to cut.

The solid crystalline rocks that are harder than steel will do whatever finish they are given. For example, steel files. Lets say you made a file out of quartz. If you make the grooves large, it will remove lots of metal= coarse grit. if you make small grooves, it will remove less metal =finer grit. If you polish it, it will smooth/polish metal = finishing grit.

Please correct me if I'm wrong...

Because last time I checked if you lap a Norton 1k up to 325 its 1k, if you lap it up to 1k its still 1k, and if you lapped it with 2000 its still only 1k. If you lap a Norton 8k up to 325 its still an 8k, if you lap it up to 1k its still an 8k, and if you lap it up to 2000, its still an 8k. Because waterstones almost always are bonded abrasive, and the size and percentage of abbrasive determines grit, not smoothness. With something homogenous, single-crystaline and harder than steel, ie a textured surface, ie a jade jasper quartz etc hone, the finish on the surface determines the grit, like a series of steel files getting finer and finer.

let's set aside single macrocrystals. Jade and jasper are not single large crystals. they are composed of microscopic crystals as is novaculite.

Yes.... but a large rock of jasper is a large rock of jasper.... with a combined hardness harder than steel, so I don't see how the steel is going to keep refreshing the smaller crystals?

How can you honestly say that if I purposefully textured something that is harder than steel that somehow through use the steel would break it down into its smaller particles? That doesn't make any sense.

This is what I recommend you do to prove it to yourself. Get a hone that you don't mind scratching, the side of a norton for example, or the side of a natural. And take a blade you're okay with damaging, maybe a kitchen knife or a nail. Scratch the hone. Notice that the hone scratches (this means the steel is harder than the hone). Now take the knife and try and scratch glass, or if you have on hand, quartz jasper jade corundum etc. You won't be able to scratch it. You'll blunt the blade. This is called "Moh's test for mineral hardness" and is rocks 101. Even if you have a bonded stone with cutting particles harder than steel, if the stone is not harder than steel the bonds break and it scratches. the little particles are breaking off and you get grit based on these particle sizes. If the stone is harder than steel the particles will almost never break off.

Yes, water erodes canyons. Over how many hundreds of years? and many if not most canyons are in sandstone. Plus, that water is flowing continuously. And water can only eroded chemically. What does the eroding is all the SAND and ROCKS and PARTICULATES in the water. The water is constantly rubbing them, like sandpaper.

i dont need to test. i have novaculites. I understand how it works which is why such things make unreasonably pitiful hones.

perhaps you should sign up for experience 101

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Originally Posted by khaos

Yes.... but a large rock of jasper is a large rock of jasper.... with a combined hardness harder than steel, so I don't see how the steel is going to keep refreshing the smaller crystals?

How can you honestly say that if I purposefully textured something that is harder than steel that somehow through use the steel would break it down into its smaller particles? That doesn't make any sense.

This is what I recommend you do to prove it to yourself. Get a hone that you don't mind scratching, the side of a norton for example, or the side of a natural. And take a blade you're okay with damaging, maybe a kitchen knife or a nail. Scratch the hone. Notice that the hone scratches (this means the steel is harder than the hone). Now take the knife and try and scratch glass, or if you have on hand, quartz jasper jade corundum etc. You won't be able to scratch it. You'll blunt the blade. This is called "Moh's test for mineral hardness" and is rocks 101. Even if you have a bonded stone with cutting particles harder than steel, if the stone is not harder than steel the bonds break and it scratches. the little particles are breaking off and you get grit based on these particle sizes. If the stone is harder than steel the particles will almost never break off.

Yes, water erodes canyons. Over how many hundreds of years? and many if not most canyons are in sandstone. Plus, that water is flowing continuously. And water can only eroded chemically. What does the eroding is all the SAND and ROCKS and PARTICULATES in the water. The water is constantly rubbing them, like sandpaper.

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Now is this correct??? I thought water erodes by mechanical not chemical. If it was chemical wouldn't the water dissolve the sand??
Forgive me, I flunked chemistry. LOL

Sand is formed with covalentt bonds whihc don't dissolve. Things like lime is calcite which is ionic so it dissolves. If you were to have streams of deionized pure water it would be a pitiful eroding agent. You are correct in that water erodes mechnically, it picks up particles and grinds them together. The water itselsf does not cut anything. It can't.
KevinT I'm not gonna argue this any more. Yes, you can make a hone out of solid rocks with high mineral hardness. you just have to texture them.

A 10k stone will always be and cut as a 10k stone regardless of how it is lapped, however, it will not cut at the same rate nor have the same tactile feedback regardless of how it's lapped. A smooth polishing stone makes for much quicker work. This is evident when polishing large surface areas of steel.

As one final piece of evidence, how often do we have to lap bonded abrasive stones? How often do you lap a dmt (yes technically it is abrasive bonded to a surface, but for all practical purposes, it is a solid with a texture, and a hardness greater than steel)