Thread: Synthetic Nagura - better understanding requested

Hello everyone,

I'm hoping to get some answers on why synthetic nagura sometimes I have grit ratings? I know that these nagura are more of a cleanup stone/correcting stone, but I do not understand why the grit rating. I know that with the asano nagura there is a progression (typically botan --> tenjou--> mehiro --> komo [sorry for the spelling]) but I have heard that these synthetics are not for progression and to make a slurry from them will pollute the slurry with larger grit than desired. So am I correct, and if so why the grit ratings. I am posting an example in hope for y'all to have an example of what I'm looking at and talking about.

Synthetic stones are man made and consistent so their performance is known and they can be assigned a grit. Natural stones are not consistent and only through use by many people can a particular stone be characterized as a finisher or pre finisher etc. Over time locations produce certain stones and those pieces from those location get a reputation. A Coticule for instance has no assigned grit rating and you will see members talk about them depending on the location in the mine they are from and the time they were mined. Some say they are fast others say slow some are great finishers and some not so much.

Also grit ratings are somewhat different from certain countries to others especially from the East.

Originally Posted by thebigspendur

Synthetic stones are man made and consistent so their performance is known and they can be assigned a grit. Natural stones are not consistent and only through use by many people can a particular stone be characterized as a finisher or pre finisher etc. Over time locations produce certain stones and those pieces from those location get a reputation. A Coticule for instance has no assigned grit rating and you will see members talk about them depending on the location in the mine they are from and the time they were mined. Some say they are fast others say slow some are great finishers and some not so much.

Also grit ratings are somewhat different from certain countries to others especially from the East.

Yes I very much agree. However my question is not about the comparison between natural and synthetic but only mention progression as a reference and know that comparing natural progression and synthetic progression is like comparing apples to oranges.

But my question is solely why the grit rating on the synthetic naguras at all. I notice that for them you will find #1000, #3000, #5000, and #8000. But if they pollute slurry and used for cleaning/correcting, then why the grit rating at all. The closest thing I've found is that you match the nagura grit with the base synthetic stone grit, but what does that do? Why can't you use an 800 with a 8000 base or visa versa?

It depends on your goal

They can be used EXACTLY like the Natural Nagura in a progression on a harder higher grit hone..

ie: I can take those marked synth nargura, put them on a Gokuyama 20K and do everything I can do on a Nakayama and the Natural nagura,,,, Yes really

The edge may feel different but the progression works the same

I think, the toppic becomes convolutet, if you use the term Nagura for each of the different uses it serves in this field.

The pictures you chose are typical for different uses: the first one is mainly used to clean the surface of an artificial stone of residue. The slurry created is not meant to serve for a specified use afterwards, so it's mostly used under running water. The second Nagura is meant to create slurry specifically to be useful during sharpening on your artificial stone.

Let's describe the different uses:

cleaning:
mostly coarser, dense stones of a less harder material are preferred, but you can try any stone you have. If it serves your purpose, go for it.

conditioning:
make the surface smooth, break used and dull particles out of the surface. You want to do that with a suitable stone and that very much depends on how hard the artificial stone is that you are going to use the Nagura on. Many times the first type of Nagura you use for cleaning serve in this purpose too.

create slurry:
you create additional slurry before sharpening on your artificial stone. You want a specific particle size for this, otherwise you would get a coarser finish, a step back in your sharpening process. If you create a certain finer slurry, it helps very much to prevent additional loadup of you stone. Mostly you simply wash the slurry of, and the stone surface should be relatively clean. Slurry helps to brak down the swarf particles and it limits a foil burr.

On artificial stones the first to uses don't need a specific grid of the Nagura, the particles are mostly swept down the drain before the artificial stone is used anyway.

But if you intend to use the created slurry for your sharpening process you want it to be of a clearly defined grid size.

Originally Posted by gssixgun

It depends on your goal

They can be used EXACTLY like the Natural Nagura in a progression on a harder higher grit hone..

ie: I can take those marked synth nargura, put them on a Gokuyama 20K and do everything I can do on a Nakayama and the Natural nagura,,,, Yes really

The edge may feel different but the progression works the same

I think I may like trying that out.

What Hein31 and Gssixgun said.

They're fun to play with. A while back I was looking for ways to set bevels with a natural stone and expand the low end of my one-stone honing kit. The solution was a marriage of synthetic and natural materials. I grabbed a Naniwa 800 grit hone and lopped off a nagura sized piece.

Bingo.

Now residing in my Cnat tackle box is everything needed to go from bevel set to final polish on that one stone via nagura.

Rlmn. I'm sorry to high jack your thread but I can't seem to figure out how to send you a private message.
I live in White Pine and I was wondering if I could talk you into honing my sr. Pls email me at [email protected].

Thank you

It depends on your goal

They can be used EXACTLY like the Natural Nagura in a progression on a harder higher grit hone..

ie: I can take those marked synth nargura, put them on a Gokuyama 20K and do everything I can do on a Nakayama and the Natural nagura,,,, Yes really

The edge may feel different but the progression works the same



That and you may want a progression, to smooth out a high grit synthetic or even Natural stone face.

I use high grit synthetic slurry stones to refresh synthetic stone faces, when I do not want to get up and use a diamond plate at the sink.

I often use a progression of synthetic full size stones, to finish lap stones, both synthetic and naturals. Does it make a difference, who knows? It does not hurt…

Additionally, using Natural Nagura and Natural stones as slurry stones, produce some interesting results.

I recently honed a razor with a Naniwa 8k Junpaku, Snow White, and,Tsushima slurry, with interesting results, a hazy bevel with a super straight edge. It also removed 4k stria quickly.

Many natural stones continue to break down producing much finer finishes. Do not get, so caught up in the look of the bevel, that you forget about the edge.

Experiment and find what works for you.

Not to derail this thread, but from the comments, I'm interested in a range of base stones for use with synth stones cut to nagura size. Gokumyo 20k and a Cnat were mentioned. Perhaps a translucent Arkansas would work similarly? Or frosted plate glass? Any suggestions?