Question about slurry on a JNAT

[Monsieur Blaireau]

I recently got an Ozuku Asagi from chefknivestogo, then picked up a Mejiro nagura and an Ozuku Tomo nagura from Aframes Tokyo. I get a nice slurry from the Mejiro without too much effort. With the Tomo, however, I have had mixed results, at best. I did manage to get a light slurry at one point, but that was after giving up on an initial attempt, and since then I haven't been able to repeat the success.

I have seen grooves cut in slurry stones, once on a CNAT I got from another member here, and again on an Ozuku tomo nagura I saw posted on the BST.

Would grooves ease my path here, or damage the nagura? Am I missing something else entirely?

Thanks in advance.

 

[Gamma]

I'm not a fan of cutting notches into any type of Nagura.

There are other ways to get slurry out of a hard Tomo/stone combo.
Soak the Tomo or the top of the Awasedo - or take the polish off the face of the Tomo with a lower grit w/d.
Another thing to try is to round one long edge/side on the Tomo and use it with a gentle rocking motion.

Getting a softer Tomo is another option.

 

[professorchaos]

I'm not a fan of cutting notches either. I soak the top of the stone for a few minutes. There's usually still a puddle on top when I start raising the mud.

 

[casus4844]

I have the same stone as you do. Getting slurry from the Tomo is going to require much more effort than the Mejiro. I've never made grooves on my tomo but maybe other members can chime in.

 

[jpcwon]

I too have an Ozuku Asagi. I found that the Ozuku tomo was causing me problems when finishing & was more effort to raise a slurry than it was worth (it is VERY hard). So I ended up settling on a Nakayama Kiita tomo that is much easier to use, and the edges it produces are fantastic...Perhaps look into obtaining a different tomo?

 

[Monsieur Blaireau]

Thanks for the responses. maybe I was being too literal in my interpretation of "Tomo" as "same" or "friend"; I thought the ideal tomo nagura was from the same stratum as the Awasedo. But a softer one would make sense, as the mejiro isn't really giving me any trouble. Meantime, I'm going to try soaking it longer - that may have been what led to the positive results the time I did get a slurry.

 

[Brooksie967]

If you're against cutting grooves (there's no problem doing that) and you've tried putting it on 80 grit wet dry to scuff the surface and you're still having issues, smooth a smaller section of it and use that. The smaller surface area won't stick as much. Also, rounding it off and rocking it would work. You've got lots of options just have to pick what's best for you. Honestly I'd cut the grooves, there's nothing wrong with doing that at all, just isn't pretty.

You're right about the meaning of the tomo but it doesn't necessarily mean that it matches the base stone. It matches it in the sense that it's partnered with it properly. It should be slightly softer than the awesado.

 

[mainaman]

When I started, I did not know about the grooves in the tomonagura ans how that could help with slurry generation.
When I found out that many cut grooves I did too to some of my tomonagras, did not really like the idea too much.
I reverted back to plain tomonagura. In the end the tomonagura to work well has to be reasonably soft one, in your case it looks like you have a harder one that does not slurry easy.

 

[Doc226]

I round off one of the edges and rub the tomo while rocking it.

 

[P Funk]

Are the grooves in the Tomo to aid with producing slurry (theoretically)?
Or are they to prevent the Nagura from sticking to the hone and possibly scratching?
I think I heard somewhere it was the latter.

I have the same stone and have grooves in tomo; it seems to help rub the stone effectively though I don't think it helps with slurry production. The stone is very hard.
I also have botan and mejiro nagura which I have not put grooves in nor do i plan to do so.

 

[xuzxuz]

Another thing to try is to round one long edge/side on the Tomo and use it with a gentle rocking motion.

Thats what I do. Raises slurry in a hurry (well in more of a hurry than using a whole side).

Clearly it's working by increasing focal pressure.
What effect this has on the stone, I don't know.
If the stone has hardened veins, there is a possibility that the "edge rubbing" could dish out the stone surrounding those veins faster.
Which would be bad. But I can't be sure.

 

[mainaman]

Are the grooves in the Tomo to aid with producing slurry (theoretically)?
Or are they to prevent the Nagura from sticking to the hone and possibly scratching?
I think I heard somewhere it was the latter.

I have the same stone and have grooves in tomo; it seems to help rub the stone effectively though I don't think it helps with slurry production. The stone is very hard.
I also have botan and mejiro nagura which I have not put grooves in nor do i plan to do so.

less sticktion to the base

 

[mainaman]

Thats what I do. Raises slurry in a hurry (well in more of a hurry than using a whole side).

Clearly it's working by increasing focal pressure.
What effect this has on the stone, I don't know.
If the stone has hardened veins, there is a possibility that the "edge rubbing" could dish out the stone surrounding those veins faster.
Which would be bad. But I can't be sure.

this works with clean stone, if thereis any inclusions in the tomoagura it will scratch the base.
One other way to use tomonagura is to make a flat along one of the edges, then you have less surface to rub with and that helps make easier slurry

 

[SliceOfLife]

I've seen a few guys cut channels in their tomo's... I can't remember a single one who was glad they did.

 

[Gamma]

this works with clean stone, if thereis any inclusions in the tomoagura it will scratch the base.
One other way to use tomonagura is to make a flat along one of the edges, then you have less surface to rub with and that helps make easier slurry

Hmm - I think something is missing from that equation.
From my perspective,

if the inclusion in the Tomo is harder - it can scratch the stone and it doesn't matter if the tomo is flat or rounded in that case.
if the inclusion in the Tomo is softer - then it won't scratch the stone, regardless of whether it's rounded or flat.

 

[mainaman]

Hmm - I think something is missing from that equation.
From my perspective,

if the inclusion in the Tomo is harder - it can scratch the stone and it doesn't matter if the tomo is flat or rounded in that case.
if the inclusion in the Tomo is softer - then it won't scratch the stone, regardless of whether it's rounded or flat.

Obviously I meant harder inclusion.

 

[BakerAndBadger]

Ok, maybe I'm missing something but isn't the whole idea of using a tomo to ensure that you actually hone with the awasedo's slurry and not the nagura when finishing? Surely if you use a softer tomo you'll end up honing with the slurry of the nagura and very little from the awasedo. We then get back to the whole issue of the importance of the awasedo when honing.
Now I'm probably getting this all wrong so Gamma or some other Jnat wizard pls correct me.

 

[life2short1971]

When using two very hard stones together I take the slurry stone and give it a few circles wet on my DMT 220grit and the slurry made plus the roughened surface easily make enough slurry for the task at hand.

 

[Brooksie967]

+1 with what Scott said. Great idea just be careful with a NEW DMT as users have reported diamonds dislodging (i have yet to have that happen)

 

[SliceOfLife]

Ok, maybe I'm missing something but isn't the whole idea of using a tomo to ensure that you actually hone with the awasedo's slurry and not the nagura when finishing? Surely if you use a softer tomo you'll end up honing with the slurry of the nagura and very little from the awasedo. We then get back to the whole issue of the importance of the awasedo when honing.
Now I'm probably getting this all wrong so Gamma or some other Jnat wizard pls correct me.

If your tomo is harder then your stone, then yes. You can use a softer one though and it'll basically just act as an extremely fine nagura though... which assuming the particles it releases are similar in size and makeup to your stone (aside from the stone being softer) will work much the same as a harder tomo would. I don't think there is a "right" way for a tomo to work, you just find one that works how you want it to. My stone is glass and the tomo I wound up keeping (after trying 4 + DMT slurrying) is even harder. Yes it doesn't slurry much or fast, but damn does it give me a lightning edge.