Thread: Nakayama Maruka

A few months ago I was advised to try a DMT slurry (It had been about a year since I last tried) so I purchased a fine DMT credit card.
Raised a slurry, leaving no visible scratches on the hone. The results were bad. If I recall it felt like the edge had regressed or had become rougher.

The DMT is scratching the surface of the stone and that surface is what gives you your desired edge in conjunction with the slurries.

The Tomo (not sure about the other Naguras) performs polishing whilst releasing some base stone particles It puts a shine on my Nakayama, a DMT shines nothing.

Above is what was explained to me by some one who is very knowledgeable and it makes total sense to me.

I've also had better results from the softer Naguras rather than the harder types. The harder ones releases more of the base stone particles.

I'm not saying that you don't know your stuff, you know more than me I can tell that.

How you are getting great results from a DMT plate or better results than with a Tomo is beyond me. Maybe it has some thing to do with the different make up of stones and their particles? I know when I lap my Nakayama it releases a dark brown slurry that smells like mud. My Shobu releases white slurry. So these stones have different attributes .

I could be wrong but I think more people get better results with Naguras rather than DMT plates.

Cheers

Originally Posted by JOB15

A few months ago I was advised to try a DMT slurry (It had been about a year since I last tried) so I purchased a fine DMT credit card.
Raised a slurry, leaving no visible scratches on the hone. The results were bad. If I recall it felt like the edge had regressed or had become rougher.

The DMT is scratching the surface of the stone and that surface is what gives you your desired edge in conjunction with the slurries.

The Tomo (not sure about the other Naguras) performs polishing whilst releasing some base stone particles It puts a shine on my Nakayama, a DMT shines nothing.

Above is what was explained to me by some one who is very knowledgeable and it makes total sense to me.

I've also had better results from the softer Naguras rather than the harder types. The harder ones releases more of the base stone particles.

I'm not saying that you don't know your stuff, you know more than me I can tell that.

How you are getting great results from a DMT plate or better results than with a Tomo is beyond me. Maybe it has some thing to do with the different make up of stones and their particles? I know when I lap my Nakayama it releases a dark brown slurry that smells like mud. My Shobu releases white slurry. So these stones have different attributes .

I could be wrong but I think more people get better results with Naguras rather than DMT plates.

Cheers

Well in the whole dmt/no dmt debate, I've never heard anyone suggest using a brand new dmt. The thing needs to be well worn, not fresh out of the packaging. How long have you been honing razors and how many different razors have you honed? Where did you purchase your hone, and have you had good results before? I think there is more at play in your story than just the issue of dmt slurry.

Originally Posted by JOB15

A few months ago I was advised to try a DMT slurry (It had been about a year since I last tried) so I purchased a fine DMT credit card.
Raised a slurry, leaving no visible scratches on the hone. The results were bad. If I recall it felt like the edge had regressed or had become rougher.

The DMT is scratching the surface of the stone and that surface is what gives you your desired edge in conjunction with the slurries.

2 reasons a DMT will scratch the stone.
1. It has high spots. These will create irregular patterning (See pic with obvious circled areas)
2. The stone is not "well" worn.

A well worn DMT C will leave a virtual mirror finish on a stone even finer than the 1200 Atoma surfaced stone pictured below.

Originally Posted by onimaru55

2 reasons a DMT will scratch the stone.1. It has high spots. These will create irregular patterning (See pic with obvious circled areas)2. The stone is not "well" worn.A well worn DMT C will leave a virtual mirror finish on a stone even finer than the 1200 Atoma surfaced stone pictured below.

My experience has been the same as Oz's. Fresh ones scratch, mellow ones don't. Of course there are some very fine invisible scratches, as Alx points out, the "nagura", natural or diamond, has to abrade the hone or there is not slurry.Cheers, Steve

I agree with all of the above. My experience is that a well used DMT 325 will leave very fine scratches on the hone surface, and the first use of nagura/tomonagura for the slurry the stone will be completely smooth.

Originally Posted by alx

You are covering a lot of bases here. Let me ask you. With the DMT slurry, what grit was the DMT and what were the negative effects?

When I use a tomonagura on the surface of my base stone I am roughing up the surface on purpose in an effort to release the slurry particles. If the base stone is super level 5+++ the idea is that the tomonagura nagura will get roughed up so that the grit comes from the nagura. With a medium hard base stone it is easier to match up a nagura that is compatible in a way that both the base and the nagura contribute some of their slurry and both base and tomo get roughed up. With softer base stones they will sometimes self slurry.

It is all same with a white Mikawa type nagura, and the same with a Diamond Nagura or a tomonagura, that is what they are for and if they did not rough up the surface you would not use them because with no abrasion there would be no slurry provided to speed up the cutting action on your razors.

This is exactly what happening to a lot of fellows here who bought level 5++ or harder base stones and were provided cheap level 5++ tomonagura. Each stone scratched the other in an uncontrolled and uncompromising way.

The idea in my opinion in using any nagura is to rough up the stone in a controlled way, not too rough and not too smooth but instead tailored to the job at hand. Usually the natural nagura is a slightly coarser stone to begin with and less expensive per gram, but it can be advantageous to sometimes use a nagura that is finer than your base stone and hardly ever or rarely advantageous to use a piece of the base stone as a nagura. Quality natural nagura are often more expensive per gram than your base stone. In either way you are using up grit, depleting part of one or both of your stone to perform a task. Every action requires energy, and the fuel of honing stones is their grit. If you don't use your base stone grit but choose to substitute an alternate grit source like a tomonagura, well that is fine too. But no matter the source if you want to remove steel with a Jnat, loose slurry is your ticket.

Softer nagura is not necessarily better nagura, high quality nagura just like base stones comes down to percentage of grit per weight which in the right hands can represent cutting speed. We are all here interested in cutting speed whether we admit it or not. Three days to set a bevel and 4 more days to finish it. Or one day to set and two 24 hour days to finish it off to shave ready. No one here is interested in doing that week after week. Cutting speed and grit quality and skill and technique is what honing razors is all about.

Many super hard 5+++ stones are grit rich but you cannot access the grit without a diamond nagura. If you want to just use your Japanese Natural 25mm thick super hard and expensive stone as a polishing stone you might just as well use an Arkansas with a tomonagura or Mikawa nagura, you will get about the same results because it will be the nagura doing all of the cutting while the base stone just acts as a polisher or burnisher platform. A medium hard grit rich and expensive Japanese natural will easily contribute some of its own grit and is more flexible to use because it can act as a platform for your nagura while at the same time it will provide some of the grit in the mix.

I have gotten some amazing edges from a level 5++ or 5+++ Jnat's with a really fine diamond plate generated slurry. These very hard stone slurries can be very aggressive in the initial stage and when breaking down can leave a fine hazy finish on almost any blade. At the same time I have gotten some really amazing edges off a level 5+++ stone by using nagura and Mikawa nagura. It is all a matter of style.

I will not deny that a diamond plate scratches my base stone, but I will tell you that my and your stones heal surprising easy. The shallow scratches left from a worn out #1200 Atoma are so shallow that you cannot see them. Those from a new DMT 300 you can see and I do not know why anyone would use that coarse a diamond plate anyhow for raising a slurry. The scratches left from a mellow Diamond Nagura will not be noticed and will heal as soon as you touch the stone with a tomonagura. The same mechanical healing happens after using a DMT but it takes longer or more rubbing. I only know of one person who wears out a Japanese natural stone through regular use and he is a furniture maker. I would like to meet a person from this forum who has worn out a Jnat. Most of us will die with 80% or so of the thickness of our stones remaining.

Bladesmiths love diamond plates for shaping steel, stone users love diamond plates for lapping (shaping stone). This indicates to me that if stone or blade users 200 years ago had cool diamond plates like we do, they would have found and developed some creative uses of them and surely some of them would have used them to raise a slurry. The rumor that was floating around 3 or 4 years ago that "No one in Japan uses diamond plates to raise a slurry" was stupid. Of course people did, and more do now, just like here in the the U.S. and Europe. Some fellows stick with the old party line because they feel safe but creative craftspeople are always looking for new tools and new ways to use tools.

Next time you lap your stone, try and use the slurry instead of just washing it down the drain.

Alex

Excellent points Alex, I like the fact that you are articulating based on your experience, which IMO is difficult not to beleive.

Ok, lot of great discussions here. Just trying to get the terminology straight. A NAgura could be a Mejiro, Tenjou Botan, or Koma. in Japanese circles, could be more kinds.

A Tomo is a small piece of the same stone is my Beleif? For example if I'm using a Nakayama Kita the tomo nagura is a small Nakayama kita as well? Correct?

Scientifically then we are grinding two equally similar surfaces (hard, homogeinity, granularity etc) like diamond on diamond. I therefore would like to assume but would refrain that this too will scratch both surface nagura and hone similarly and may probably raise very very less amount of slurry albeit very fine.

Originally Posted by prodigy

Well in the whole dmt/no dmt debate, I've never heard anyone suggest using a brand new dmt. The thing needs to be well worn, not fresh out of the packaging. How long have you been honing razors and how many different razors have you honed? Where did you purchase your hone, and have you had good results before? I think there is more at play in your story than just the issue of dmt slurry.

I've been honing for 2 years but I might have been saying that for quite a while, I don't have a specific time line.
I hone lots of different types of blades ,mainly European apart from Hart Steel and a custom.
My hone came from JNS ,the best finisher he had in stock at the time of purchase.
Have I had any good results before , I don't understand the question.
I'm also Aquarius

Originally Posted by onimaru55

2 reasons a DMT will scratch the stone.
1. It has high spots. These will create irregular patterning (See pic with obvious circled areas)
2. The stone is not "well" worn.

A well worn DMT C will leave a virtual mirror finish on a stone even finer than the 1200 Atoma surfaced stone pictured below.

You live and learn. I never thought a DMT plate could create a mirror finish.

Originally Posted by Steve56

My experience has been the same as Oz's. Fresh ones scratch, mellow ones don't. Of course there are some very fine invisible scratches, as Alx points out, the "nagura", natural or diamond, has to abrade the hone or there is not slurry.Cheers, Steve

I should wear my DMT down some and try again. But dosnt a Nagura break down into finer pieces of slurry than base stone?