Natsuya polish

[CodyJ]

Hello everyone I recently got a natsuya and am attempting to polish my new HF Gyuto. I’ve attached a crappy video of the polish I’ve achieved after about 20 minutes of work and in my opinion it’s an ok polish but I have these awkward looking scratchy/shiny blotchy areas that I’m unsure of how to smooth out.


I’d like to know

A. What I did to get the smooth areas
B. How I made the mistakes of the not so pretty spots and
C. What I should be doing in terms of polishing, ie: I’ve been doing a forced slurry with an atoma 140, little water, more water etc.


I’m SUPER green and inexperienced and just looking to learn so any tips would be appreciated!

 

[ethompson]

Starting with a slurry definitely isn’t a bad thing, but the finish will be less fine. These stones generally are hard and do their best work when they’re almost, but definitely not, dry. So just add little splashes of water at a time and sue super light pressure and small strokes. It’ll start refining nicely then. Won’t ever be fully scratch free like a finer suita stone, but you can get lots of detail and a v pretty uniform finish.

 

[dragjp]

On the other side, slurry tends to make the surface hazier especially with mid-grit stone like Natsuya. Maybe also try to start without any and polish in the way Ed described above, see if you like the result.

 

[CodyJ]

Starting with a slurry definitely isn’t a bad thing, but the finish will be less fine. These stones generally are hard and do their best work when they’re almost, but definitely not, dry. So just add little splashes of water at a time and sue super light pressure and small strokes. It’ll start refining nicely then. Won’t ever be fully scratch free like a finer suita stone, but you can get lots of detail and a v pretty uniform finish.

Understood thanks dude! Beautiful stone.

 

[CodyJ]

On the other side, slurry tends to make the surface hazier especially with mid-grit stone like Natsuya. Maybe also try to start without any and polish in the way Ed described above, see if you like the result.

Will give it a go. So much to learn..

 

[ethompson]

And if you don’t figure it out with experimentation I’m just up the road and am happy to help, I use these all the time cause I really like them and

 

[CodyJ]

And if you don’t figure it out with experimentation I’m just up the road and am happy to help, I use these all the time cause I really like them and

Thanks man I’m gonna mess with it a bit and see what I can do. I’ll let you know though thanks so much

 

[Uncle Danny]

Natsuya has a tendency to spit out rough particles, making it a bit frustrating trying to get a clean polish.
You need to work with pressure, slurry and water. It can take a long time and some stones won’t let you get a finish you truly accept.

 

[lesslemming]

You have embarked on a journey and your starting point, it seems, is better than mine. So let us start by saying you did a better job on your first attempt than many others, including myself.

The road before you is fraught with impulses that have no greater desire than to roll up your dollar bills and smoke them. A little voice wondering if another stone will get you there is something you will get to know soon.

With a Natsuya, you have a fantastic Nakatoishi, capable of doing a little bit of grinding (I mean metal removal) that leaves you with a contrasty, detailed, albeit slightly scratchy finish. One can be very happy with that.
Here is a good video with lots of background information on these stones:
(Not my video, of course)

Now, I do not know your knife or the condition it is in.
In my opinion, a Natsuya would be a starting point for a knife that has a very even bevel. Large, thin surfaces like a knife tend to warp, wobble, bend and be generally uneven. Such unevenness can result in blotchy and uneven results in the finish if the stone one uses is incapable of removing enough metal to remove said unevenness.

Therefore, I always like to start with a hard and flat stone that will show high and low spots before I spend time on a Nakatoishi (medium fine JNAT) or even a finisher.

Such a stone could be a Shapton Glass 500 or any other of the highly regarded hard and coarse stones. These will show unevenness and are capable of removing high and low spots at the same time.

My recommendation: mark the area you wish to polish with a sharpie (just some lines or a grid pattern). Let it dry. Polish on your Natsuya for a moment and check where the marker is removed first (indicating either a high spot or a point where you focus pressure unevenly) and take note of any areas the sharpie is not or only reluctantly removed (low spot or an area you don’t focus enough on).

Like I said, a Natsuya wouldn’t be my choice if there were high and low spots to be removed. A coarser synth or some wet dry sandpaper on a flat surface may be required.

Laying the correct foundation is challenging but the best way to ensure success in the later stages

 

[CodyJ]

You have embarked on a journey and your starting point, it seems, is better than mine. So let us start by saying you did a better job on your first attempt than many others, including myself.

The road before you is fraught with impulses that have no greater desire than to roll up your dollar bills and smoke them. A little voice wondering if another stone will get you there is something you will get to know soon.

With a Natsuya, you have a fantastic Nakatoishi, capable of doing a little bit of grinding (I mean metal removal) that leaves you with a contrasty, detailed, albeit slightly scratchy finish. One can be very happy with that.
Here is a good video with lots of background information on these stones:

Now, I do not know your knife or the condition it is in.
In my opinion, a Natsuya would be a starting point for a knife that has a very even bevel. Large, thin surfaces like a knife tend to warp, wobble, bend and be generally uneven. Such unevenness can result in blotchy and uneven results in the finish if the stone one uses is incapable of removing enough metal to remove said unevenness.

Therefore, I always like to start with a hard and flat stone that will show high and low spots before I spend time on a Nakatoishi (medium fine JNAT) or even a finisher.

Such a stone could be a Shapton Glass 500 or any other of the highly regarded hard and coarse stones. These will show unevenness and are capable of removing high and low spots at the same time.

My recommendation: mark the area you wish to polish with a sharpie (just some lines or a grid pattern). Let it dry. Polish on your Natsuya for a moment and check where the marker is removed first (indicating either a high spot or a point where you focus pressure unevenly) and take note of any areas the sharpie is not or only reluctantly removed (low spot or an area you don’t focus enough on).

Like I said, a Natsuya wouldn’t be my choice if there were high and low spots to be removed. A coarser synth or some wet dry sandpaper on a flat surface may be required.

Laying the correct foundation is challenging but the best way to ensure success in the later stages

Thank you for such a detailed response. Luckily for me the gyuto I’m using is a HF that has already had its bevels worked on with naturals. I’m finding some success although there are random times where I believe some coarse particles will scratch the bevel and mess up my polishing work that I had done leading me to start again. I definitely have much to learn!

 

[ethompson]

Worth noting that the stone @CodyJ has is an old sun Tiger branded stone not one of the newer ones that are retailed primarily from hitohira and their network.

Sometimes look similar, but actually rather different. The older ones are more like an Aizu but 500ish grit coarser, much finer than the common refrain I hear of natsuya being 800-1500 grit. There can be some particle inconsistency certainly, but usually nothing too crazy and certainly nothing that would lead someone to drop down a grit to remove it.

The old stones are rather tricky on highly convex surfaces though just because they’re so hard.

I prefer to work without slurry, but to to condition the surface freshly before starting and then let the surface of the stone refine as I go which is when bright burnishing will start.

 

[CodyJ]

Worth noting that the stone @CodyJ has is an old sun Tiger branded stone not one of the newer ones that are retailed primarily from hitohira and their network.

Sometimes look similar, but actually rather different. The older ones are more like an Aizu but 500ish grit coarser, much finer than the common refrain I hear of natsuya being 800-1500 grit. There can be some particle inconsistency certainly, but usually nothing too crazy and certainly nothing that would lead someone to drop down a grit to remove it.

The old stones are rather tricky on highly convex surfaces though just because they’re so hard.

I prefer to work without slurry, but to to condition the surface freshly before starting and then let the surface of the stone refine as I go which is when bright burnishing will start.

When you first start and have conditioned the surface with an atoma and have built up some slurry, to further refine your scratch pattern and start burnishing the steel do you wash off the surface and lighten your pressure?

 

[ethompson]

First you can use a plate to raise a light slurry and polish with that, keeping the slurry wet and loose. Next I’d lap the surface again to rough it up a bet, then rinse off all the slurry and work with just water. After awhile the surface of the stone will glaze over a bit and slow down considerably and this is when you can start pushing the refinement. I always recommend light pressure, pretty rare I’m using heavy pressure on any project at any point,

 

[ethompson]

Great news is that once you learn to master a natsuya in terms of surface prep, slurry management, water management, pressure, etc. - you’ll have a super strong base for figuring out how to get the most out of other stones as well.

 

[lesslemming]

Great news is that once you learn to master a natsuya in terms of surface prep, slurry management, water management, pressure, etc. - you’ll have a super strong base for figuring out how to get the most out of other stones as well.

And that’s why people keep recommending hard, medium fine Nakatoishi like the Natsuya. They can do excellent work and teach you the foundation

 

[ReiHamono]

I really enjoy the shiro nagura bench stone for this more and more as time goes on.

And that’s why people keep recommending hard, medium fine Nakatoishi like the Natsuya. They can do excellent work and teach you the foundation

 

[CodyJ]

Man this is such an interesting experience. I feel like I’m beginning to understand what does what in terms of what I’m doing. The polish in my opinion has gotten a bit better. I’m finding a lot of success when I generate some slurry with the atoma, polish a bit, spray a tiny bit of water to keep everything slick and keep going. It seems when I wash off the slurry and attempt to follow the contrasty polish achieved by the slurry is when I start getting way more obvious scratches and a less clean and cohesive polish. I’m suspecting I’m not using enough water or my pressure is too much given that the surface is now more clogged and doesn’t have any slurry to help skate along the surface. The attempt to burnish is what I’m now trying to understand and get better at.


Thanks for all the tips y’all are the best

 

[user 16756]

Man this is such an interesting experience. I feel like I’m beginning to understand what does what in terms of what I’m doing. The polish in my opinion has gotten a bit better. I’m finding a lot of success when I generate some slurry with the atoma, polish a bit, spray a tiny bit of water to keep everything slick and keep going. It seems when I wash off the slurry and attempt to follow the contrasty polish achieved by the slurry is when I start getting way more obvious scratches and a less clean and cohesive polish. I’m suspecting I’m not using enough water or my pressure is too much given that the surface is now more clogged and doesn’t have any slurry to help skate along the surface. The attempt to burnish is what I’m now trying to understand and get better at.


Thanks for all the tips y’all are the best

a good way to reduce pressure is to change the position of your fingers on the blade.

instead of holding them pressing straight down, find a comfortable grip where you are only pushing (nearly only) forward. for me this means rotating my wrist outwards.

 

[CodyJ]

a good way to reduce pressure is to change the position of your fingers on the blade.

instead of holding them pressing straight down, find a comfortable grip where you are only pushing (nearly only) forward. for me this means rotating my wrist outwards.

Will try this, thanks!

 

[lesslemming]

Man this is such an interesting experience. I feel like I’m beginning to understand what does what in terms of what I’m doing. The polish in my opinion has gotten a bit better. I’m finding a lot of success when I generate some slurry with the atoma, polish a bit, spray a tiny bit of water to keep everything slick and keep going. It seems when I wash off the slurry and attempt to follow the contrasty polish achieved by the slurry is when I start getting way more obvious scratches and a less clean and cohesive polish. I’m suspecting I’m not using enough water or my pressure is too much given that the surface is now more clogged and doesn’t have any slurry to help skate along the surface. The attempt to burnish is what I’m now trying to understand and get better at.


Thanks for all the tips y’all are the best

That looks really good!

Typically, with slurry most stones create what is sometimes referred to as kasumi. This describes a hazy kind of polish which is great at hiding scratches.

When used without slurry, hard JNATs tend to burnish or at least polish more. Everything will become brighter and more reflective. This also means scratches from previous steps or the stone itself will become more evident.

As mentioned before, the Natsuya is not capable of creating a perfect scratch free polish. Even? Yes. Clean with lots of detail? Yes. Scratch-free? No.

So maybe, just maybe, you have reached what is possible with the Natsuya in terms of polishing. Welcome to the question what other stones can do. May I interest you in a Mikawa Nagura bench stone?

 

[CodyJ]

That looks really good!

Typically, with slurry most stones create what is sometimes referred to as kasumi. This describes a hazy kind of polish which is great at hiding scratches.

When used without slurry, hard JNATs tend to burnish or at least polish more. Everything will become brighter and more reflective. This also means scratches from previous steps or the stone itself will become more evident.

As mentioned before, the Natsuya is not capable of creating a perfect scratch free polish. Even? Yes. Clean with lots of detail? Yes. Scratch-free? No.

So maybe, just maybe, you have reached what is possible with the Natsuya in terms of polishing. Welcome to the question what other stones can do. May I interest you in a Mikawa Nagura bench stone?

This is what I’m thinking as well. Still have some work to do to polish better without as much slurry and just water.

I understand why so many people call this the rabbit hole. This seems quite addictive haha.

I am more in the koppa price range at the moment but will definitely be excited about trying different stones