JNat Beginners Guide to Buying: Stories of Success, Pitfalls, and Fails

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milangravier said:
I have tried about 2 months ago to test some sword polishing techniques. Damian Kordic was very kind to show me the basics.
I have done 2 knives with that technique and then go back to my own one, as I did not get the results I wanted.

What I learn : It is very hard to control and be sure you're not overgrinding the top of the bevel. Mostly because I am making knives with kurushi/hammered part on top of the blade, the shinogi is not set as a perfect line but is moving with the differences of thickness of the blade. So I was overgrinding that shinogi part, did not see I was overgrinding and when I get to finer stones I could see the stones were not touching the all bevel.
Normally, sword polishers are not grinding everywhere like from heel to tip, but they look at the blade, find the high spot or high area where there is too much material, select it and grind only that part, then look again, etc... I did not succeed to do that. It needs... eyes! it needs to know what to look at, find the subtle change of light because in some place there is too much material.
Must be little bit easier with a full polished blade compare to a blade with kurushi, maybe.

What I could see was that with the convex shaped stones + the way using them, the technique could grind very fast. For sure faster than flat stones. And the blade even with san mai, get bright so you really have a nice view on scratches and bevel shape.
The main problem of that technique is not a problem but a knowledge : you need to practice again and again so you have eyes to see your blade and see what to do looking at it, before you grind it. That need experience and knowledge, years of work. It is powerful technique, but it is just harder to learn.
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Yeah, the more one can see and can feel often lead to better outcomes. It is very admirable what the sword polishers can see with their bare eyes.
 
JDC said:
IMHO, the most important stones are the coarser ones (synthetic), as you will need to efficiently shape the blade and remove all low spots.
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I tend to disagree, but it is only my experience. Course synthetic stones leave very deep scratch patterns which are difficult to remove AND maintain geometry along the length of the bevel. It is IMO way to easy to remove too much material and end up with deep scratches that force one to remove even more material.

Over time, I've really become quite fond of the Aoto/Aizu combo for removing the makers grind marks, low spots etc, while maintaining the makers intended geometry. This is particularly true for San-Mai blades as Milan discusses above. It is a slow and laborious process, but the results I think speak for themselves.

Here is an example: 1. Knife from the maker 2. First session on the stones. 3+ today. I'm not sure I could have maintained the subtle curvature of the bevel spine/edge & heel/tip with a course stone. It would have also made it more difficult to reveal the subtle banding of the steel.

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Hanmak17 said:
I tend to disagree, but it is only my experience. Course synthetic stones leave very deep scratch patterns which are difficult to remove AND maintain geometry along the length of the bevel. It is IMO way to easy to remove too much material and end up with deep scratches that force one to remove even more material.

Over time, I've really become quite fond of the Aoto/Aizu combo for removing the makers grind marks, low spots etc, while maintaining the makers intended geometry. This is particularly true for San-Mai blades as Milan discusses above. It is a slow and laborious process, but the results I think speak for themselves.

Here is an example: 1. Knife from the maker 2. First session on the stones. 3+ today. I'm not sure I could have maintained the subtle curvature of the bevel spine/edge & heel/tip with a course stone. It would have also made it more difficult to reveal the subtle banding of the steel.

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That’s very nice finish indeed! However, not all makers deliver reasonably even bevels to customers. In fact, a lot of Japanese knives require considerable amount of regrinding to reach this level of finish. Someone like Milan who goes above and beyond is definitely precious to the community.
 
JDC said:
That’s very nice finish indeed! However, not all makers deliver reasonably even bevels to customers. In fact, a lot of Japanese knives require considerable amount of regrinding to reach this level of finish. Someone like Milan who goes above and beyond is definitely precious to the community.
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Fully agree, which is why I presented the knife I did. Dan is one of my favorite makers, but he delivers the knife with a very "rustic" finish. Some have complained that Dan's knives are all over the map in terms of grinds. Not my experience, but it's out there.

This is perhaps different then TF and some of the more notoriously uneven grinds of Japanese blades. My only point being that a slower approach to regrinding process leads to better results, at least for me. Can't put material back on the blade once you've removed it. For this reason, I generally avoid synthetic stones for anything other then edge work. Just a thought
 
Hanmak17 said:
Fully agree, which is why I presented the knife I did. Dan is one of my favorite makers, but he delivers the knife with a very "rustic" finish. Some have complained that Dan's knives are all over the map in terms of grinds. Not my experience, but it's out there.

This is perhaps different then TF and some of the more notoriously uneven grinds of Japanese blades. My only point being that a slower approach to regrinding process leads to better results, at least for me. Can't put material back on the blade once you've removed it. For this reason, I generally avoid synthetic stones for anything other then edge work. Just a thought
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Yeah it's case by case. Working with a TF bevel can be frustrating on finer stones. But as you said, coarse stones remove metal fast and can change the geometry easily. Any new polishers should have enough practices and know what they want to achieve before putting their fine cutters on coarse stones.
 
Hanmak17 said:
Fully agree, which is why I presented the knife I did. Dan is one of my favorite makers, but he delivers the knife with a very "rustic" finish. Some have complained that Dan's knives are all over the map in terms of grinds. Not my experience, but it's out there.

This is perhaps different then TF and some of the more notoriously uneven grinds of Japanese blades. My only point being that a slower approach to regrinding process leads to better results, at least for me. Can't put material back on the blade once you've removed it. For this reason, I generally avoid synthetic stones for anything other then edge work. Just a thought
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finer synths can be excellent contrast setters for folks who are into huge contrast, or for knives where you're just not gonna get anything interesting out of the cladding.

also Im kind of with JDC here that for most Japanese knives you probably should go down and just fix whatever problems immediately, rather than let them continue, with the one exception being if you have a low spot placed high enough up the grind that there is no danger of it becoming a hole in the edge. I have found this REALLY improves the performance of knives and has turned some 'mediocre' blades into some of my favorites (e.g. my Hinoura kinda sucked then I just refinished it and evened things out a bit and now it is an amazing cutter).

Ive also found that the media blasted finishes tend to look really fine but cannot be easily nuked with a natural finisher.
 
Hanmak17 said:
Fully agree, which is why I presented the knife I did. Dan is one of my favorite makers, but he delivers the knife with a very "rustic" finish. Some have complained that Dan's knives are all over the map in terms of grinds. Not my experience, but it's out there.

This is perhaps different then TF and some of the more notoriously uneven grinds of Japanese blades. My only point being that a slower approach to regrinding process leads to better results, at least for me. Can't put material back on the blade once you've removed it. For this reason, I generally avoid synthetic stones for anything other then edge work. Just a thought
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Very interesting. As a maker, I am really used to grind metal, a lot ! so for me I feel someone who want to play with naturals and their effect should go down 180 grit and fix the bevel geometry, as there is almost always something to clean, and to my experience is the only way to really play with the finish of stones at the end ! But you're very true about the fact to not to grind too much material and that some mistakes can be regretted, doing some scratches hard to erase.
Still my theory is that if the bevel is well shaped, there won't be much work to erase any 180 scratches (apart from diamond maybe). Most scratches that are hard to erase are in fact a low spot, not a deep scratch.
 
JDC said:
Any new polishers should have enough practices and know what they want to achieve before putting their fine cutters on coarse stones.
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Exactly, I've (unfortunately) bought a couple of knives off the BST over the years that were seriously f'd by previous owners attempts at thinning or removing low spots. I think maybe my opinions on this are biased accordingly...:)

I love working with natural stones, it's a more laborious process, but I find it all to be very rewarding.
 
I've had one of these and another quite similar piece from Matsunaga. Great for sharpening and intermediate work, but mine had some scratchy bits that make them unfit for the final Kasumi finishing. Edges off them are amazing though.
 
blokey said:
Not sure if this is the right thread or I should open a new one… Anyone have experience with Tanaka Aoto CKC is selling now? I have no experience with Jnat and this looks like a good one to try. Planning to use it for finishing after Gesshin 2k and doing some bevel Kasumi.
https://carbonknifeco.com/collectio...a-toishi-aoto-natural-stone-softer-discounted
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Aoto for polishing are sort of hard to come by, it seems to me most of them have at least some scratchiness to them. Agree with @DHunter86 re: being great for edges and some clean up from lower grit synths, but if clean kasumi is what you’re after, other options may do better. Not to say it’s not possible tho. If you can find one of Takeda’s soft stones, they’re my current gold standard for prefinisher - no scratching and anything from texture to a soft mirror is achievable.

That price can’t be beat, but it looks like it’s sold - did you buy it already? If so good buy, and a great place to put your first jnat data point.
 
Pie said:
Aoto for polishing are sort of hard to come by, it seems to me most of them have at least some scratchiness to them. Agree with @DHunter86 re: being great for edges and some clean up from lower grit synths, but if clean kasumi is what you’re after, other options may do better. Not to say it’s not possible tho. If you can find one of Takeda’s soft stones, they’re my current gold standard for prefinisher - no scratching and anything from texture to a soft mirror is achievable.

That price can’t be beat, but it looks like it’s sold - did you buy it already? If so good buy, and a great place to put your first jnat data point.
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Totally agreed. My Aoto isn’t great for polishing. Too scratchy. But it puts amazing edges on my vintage carbons.
 
Pie said:
Aoto for polishing are sort of hard to come by, it seems to me most of them have at least some scratchiness to them. Agree with @DHunter86 re: being great for edges and some clean up from lower grit synths, but if clean kasumi is what you’re after, other options may do better. Not to say it’s not possible tho. If you can find one of Takeda’s soft stones, they’re my current gold standard for prefinisher - no scratching and anything from texture to a soft mirror is achievable.

That price can’t be beat, but it looks like it’s sold - did you buy it already? If so good buy, and a great place to put your first jnat data point.
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Sadly not me, missed this one. Thanks for the answer!
 
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@blokey

That one looks like an oozing soft aoto.

Super duper aggressive edges. You'll get a kasumi with drag. But it'll haze up. Having tried like 10+ aoto so far, yeah this one looks softer and coarser

Yeah edge agression wise, soft aoto type stones are the best of all I've tried
 
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Second hand stones nudged me to buy. Some good stuff from reliable shops went by. A Kaedeyama and Tsuchima, a bit over 100€ each just arrived. The seller bought them in Japan. No further information added.

So far Kaegeyama felt smooth and a little slick. The seller marked the bottom as grinding surface. Top side got some scratches and laquer at the sides. Time will show what I got. Of course the deal is based on trust of "bought in a reliable toolshop in Japan"

Ordering some tools I added an Ozuku koppa from a local shop. Ozuku might be a known finisher, help to compare results.

Feel free to comment wether this is a reasonable route.

Hanmak17 said:
I tend to disagree, but it is only my experience. Course synthetic stones leave very deep scratch patterns which are difficult to remove AND maintain geometry along the length of the bevel. It is IMO way to easy to remove too much material and end up with deep scratches that force one to remove even more material.
Click to expand...
milangravier said:
Very interesting. As a maker, I am really used to grind metal, a lot ! so for me I feel someone who want to play with naturals and their effect should go down 180 grit and fix the bevel geometry, as there is almost always something to clean, and to my experience is the only way to really play with the finish of stones at the end ! But you're very true about the fact to not to grind too much material and that some mistakes can be regretted, doing some scratches hard to erase.
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I appreciate that discussion and this thread. So, once I got a foundatition to start my fist polish, where should I start?
 
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Well, I bought 3 stones to a dealer in Japan 2 years ago, I thought he was very serious... I overpaid the stones like hell, and I couldn't see some clear signals that showed me that I should have run from him.

He pretend to sell me premium stones, they are not. Lesson learned, I moved on... but it is pretty painful you know
 
TheLuthier said:
Well, I bought 3 stones to a dealer in Japan 2 years ago, I thought he was very serious... I overpaid the stones like hell, and I couldn't see some clear signals that showed me that I should have run from him.

He pretend to sell me premium stones, they are not. Lesson learned, I moved on... but it is pretty painful you know
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Ouch. Painful, yes. How did you find out that they were not premium stones? I am going through something like this right now, with this Natsuya I got from, let us say, a prolific source. I've been glaring at it, wondering: do I just not like Natsuya? Or is this not a good Natsuya?

"Worst stone purchase" would be an interesting thread, but with naturals especially, I always have to wonder if I have just not found the use in which they will be great. I am pretty sure I have at least two stones that are great, but which I have not found the right role for.
 
I talked about my stones with various specialists, who knew a lot og things! The more I read about that, the better I knew about the market. The stones have some cracks too, and this is disapointing!
 
The stones are great, I just overpaid. $1280 USD for the Shobu, $780 for the Okudo and $840 for the Nakayama
 

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D J said:
The lines don't look very bad at all from the pictures. Two of the stones are suita's, so you can expect to have su in them. You may have paid a bit more than you should but the stones look fine.
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Thanks for your post D J, yes I am not super unlucky and they are fine! I started in the world of the Jnat, and they are good enough for me right now! I know where to find premium stones on the market so, my future should be not bad at all! My guitars should be happy!
 
Stones look really nice.
This is just my perspective on the topic. My own experiences. Doesn’t matter how perfect the stone is or how much I may have paid to get it. I have to troubleshoot every knife or stone differently depending on the steel cladding stones hardness reactivity bevel flaws. There’s just a million factors. If I don’t take the time to tinker around with these things I will always be disappointed. And then I go back and start over because I find it enjoyable.
No point to my story really just a rambling stone addict.
 

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Hassanbensober said:
Stones look really nice.
This is just my perspective on the topic. My own experiences. Doesn’t matter how perfect the stone is or how much I may have paid to get it. I have to troubleshoot every knife or stone differently depending on the steel cladding stones hardness reactivity bevel flaws. There’s just a million factors. If I don’t take the time to tinker around with these things I will always be disappointed. And then I go back and start over because I find it enjoyable.
No point to my story really just a rambling stone addict.
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Good points, and nice rig! The thing I found very satisfying, is to find the perfect stone for each tool. I know this is a forum where people are sharpening their knives, but every tool is the same after all... we all love a nice silky smooth surface, that could cut anything!
 
Rangen said:
Ouch. Painful, yes. How did you find out that they were not premium stones? I am going through something like this right now, with this Natsuya I got from, let us say, a prolific source. I've been glaring at it, wondering: do I just not like Natsuya? Or is this not a good Natsuya?

"Worst stone purchase" would be an interesting thread, but with naturals especially, I always have to wonder if I have just not found the use in which they will be great. I am pretty sure I have at least two stones that are great, but which I have not found the right role for.
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There were a half dozen mines producing natsuya and unfortunately the really great ones are from a specific section of only one of the mines. Luckily that section produced a lot of stone. midgrits can be tricky haha.

The newer ones on the market (often popping up on morihei) are not at all like the old ones sold by companies like suntiger. Suntiger had all the nice stuff when it was available so if you want a good natsuya, one of their old stock stones is your best bet. There is still a risk of duds but it's sooo much lower with them. Stay away from anything with stripes unless it's been tested and fits your metrics.
 
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