I know this is an older video but I actually chose the professionals so I could use my own base… I much prefer my rubber base and the freedom of a plain stone because I can fit my stone in my drying rack which I could not do with an attached base. Also, the performance is excellent. I also really enjoy the Suehiro Cerax collection (at least for my Japanese knives). I posted this on the response but for anybody reading this a wire drying rack for kitchen plates is the greatest storing/drying solution for your stones that you could ever find for eight dollars.
The Professional series is not available in Japan. The package of your stone has a large "made in Japan" writing in English on its front, so it strongly suggests that the Professional series is launched for western markets. Its color variation to each grit is almost the same as Chosera series, so I think the Professional series is almost the same quality as Chosera series schemed by western dealers for availability.
+virtuovice yes, the quality feels the same. So they will not replace Chosera in Japan, thats interesting. it suggests naniwa is doing the same as shapton with it's professional serie and ha-no-kuromaku series. stay safe!
i got all my original nainwaa choseras on amazon, so get them befor they may run out their 400 is a pperfect choseraa why they name a different seller is a mystery, but yhe box , numbers , performance and lobster like logo and serial numbers are all their all the other are sold as nainwa, strange but i know although the 400 chosers is named on amazon description as super ceramic is some weird thing i and others have it and find it to be a true chosera
they still sell original japanese chosera and kurumaku on amazon from japan and fast sevice, i am so happy i can still get them and the price is maybe a few dollars more
A sharpening tip: Always keep the three fingers on the blade directly on the stone. This applies an even pressure the full length of the blade and keeps it true. When fingers are off to the side (so fingers are hanging over the edge) the blade touching the stone has less pressure and thus grinds less metal off on that section of blade, over time the results of this incorrect method will become very apparent. So let the blade move freely but keep the fingers on the centre of the stone at all times.
actually a lot of professional sharpeners don't like those bases and Naniwa has received countless request to get rid of it, you might be upset about that base being gone but so many are jumping for joy, the thinning stones thing is getting really old really quick though the stones are expensive enough but now getting a half to a 3rd of the stone in some cases is really not right at all!
I really didn't like the option to buy without the base, as i have a stone holder i really like and can use over the sink to wash off swarf and wet the stone when needed. I originally liked the bases, but don't like not being able to use both sides
hello, I have been looking into different brands of water stones and have heard a great deal about Shapton and the Naniwa brands. Do you have a preference between the two? what would you suggest? Thanks, Travis
Please don't worry because new series comes without a base. Choseras with base look great but they are bulky to handle and I believe there is smaller risk of cracking when stone comes without a base. Thanks for a great video.
Disappointing that they did this, can still get Chosera stones in Canada but they have to be imported. You get so much more stone with the Choseras that it's worth it to me to buy it. Running a few Shapton Ha No Kurumakus 1k 2k 5k and 400 and 3k Chosera. Want to get a Naniwa 8k snow white soon. I think the Chosera stones are beautiful with the markings and the base.
I've seen on a few commercial websites that the Chosera line is now limited to Japan only. That pretty much says enough to me. The Professional line is for expert to the barbarians.
Can you say clearly if the Chosera was better for you? Because from what you say §I understand Chosera is better even if you didn't say directly!!!! I need a the best artificial stone grit 10000 and that's my interest . I found Professional Naniwa is probably the most expensive 10.000 K but not sure! Thanks for your advices!
I wish I could do convex or scandi on my wicked edge. I did try your method on benchmade 162, but I did a garbage job. If anyone can give me advice on how to do those angles on a wicked edge; I’m all ears
I plan to buy professional to reduce risk of cracking. Remember to dry it perpendicular so both sides will dry at the same rate. Otherwise chosera is awesome
The greatest purchase I ever made for my stones was a wire drying rack for plates. I took a pair of wire cutters and cut every other wire to widen the slots. After doing that I can fit six stones and a diamond flattening plate in the rack to dry for as long as needed.
Completely off subject I know but that is swarf not slurry. ;) (I restore and hone straight razors as a hobby) But yeah, I'll be searching for a Chosera and buying a couple to keep as backups as opposed to buying the new Professional series.
im new to waterstones, I just got a king combo stone to try them out. You said that the stone is nearing the end of its life but it looks like most of the stone is still there, how thin can you get them before you have to get a new one?
+West Coast Warriors Archive you can basically use it until you're completely trough the stone as long as you keep the stone flat and flatten it if it becomes concave. This stone was about 3x the height you see here. I still use it but after this winter it's completely worn. Cheers and good luck with your stones!
Any tips on the very cheapest wetstones ( maybe a combination of wetstones) to make any knife (kitchen and outdoor) hair-shaving sharp? Looking for the absolute budget wetstones.
If you still looking the king deluxe stones seem to cut fairly well and the 1200 grit stone is avaiable on amazon for $20 (in the US). The hardest steels that I have (D2, aogami #2 shirogami#2, and CPM-20CV all get sharp on it). If you want something guarenteed to sharpen ANY steel maybe go with diamond plates, EZ-LAP sells some that are at or below $50 but those will be 6 inches by 2 inches
For sharpening a variety of bushcraft and other outdoor knifes, what stones and grits should i choose to be able to reprofile and also get a stable, scary sharp, satin finish mirror grind and egde? Something like 400 + 5000, something between as well or what? Looking for good value, "low cost, high functionality".
I have the 400 professional stone. Love it. I was bummed out it not being the Chosera. But I don't like the base since I use the rubber adj. Base. Naniwas website claims improved bonding etc. So it was interesting to watch your video. The 5k is still a thirsty stone in the series. I'm gunna skip that stone and get the" snow white" 8k and the pro 3k. Beautiful edge on that santoku I might have to ship my knives to Europe to be sharpened ;)
+Big Brown haha, thanks for the comment mate! Snow white isn't the hardest stone but also doesn't take much water. I find the Snow white to be very comfortable. The chosera 3k might be my most favourite stone of all time. It's really like skating on ice with that stone.
Vraagje: Als mijn keuze zou vallen op een Naniwa steen, welke zou dan het beste geschikt zijn voor “onderhoud” van een mes? Dus machinaal slijpen en tussentijds bijwerken met een wetsteen als een aanzetstaal net tekort komt.
just bought a professional 400 and i having a hard time getting a paper cut edge (very toothy) light or heavy preassure ? never sharpen with water stone before..(was using diamond) thanks
thanks, I just wish someone would do a side by side comparison on youtube. Who knows maybe I will do that lol. By the way, I really enjoy your vids guys. keep it up!
The new stones ARE more expensive... they have increased the price. However they are selling the old choseras at higher prices because they are 5mm larger and in higher demand.
I loved mine too, cept my 5k grew cracks all through the stone after about 3 uses. Now my 1k is doing it as well. 400 is still fine. I will never spend another dime on chosera... Naniwa super on the other hand I really enjoy for razors.
Luckily my chosera's don't show cracks. My naniwa snow white does all over the place. I also discovered a crack in my shapton ha-no-kuromaku 5000 stone sadly. I think it's the bonding of these harder stones that cause the cracking.
unless you live in Japan you shouldn't get the ha-no-kuramaku stones... they make the western versions for our climate. A lot of people use the cheaper ones without issues but I would just get the non Japanese version to be safe.
If you want the japanese version, you can get it on ebay. the most cracks due to people who soaks it too long, like cheaper stones. there are splash and go stones, soaking isn't needed
the orig chosera with base is best for me. and having good service from japan thru amazon and same old price , generally, and why use shapton pro when you can still gey ha hu kurumaku on amazon, i wont buy for the western market when i can get the rel deal on amazon
The super stones are still super stones, but dealers tend to let you know/call them new super stone... the new pros are the Chosera series’s now. At lease here in US. There are also a traditional series of stones by Naniwa too.
On the naniwa website, they explain that the professional line is a replacement for the chosera line, along with forums and most other websites that no longer sell choseras, but do still sell the professional, at a lower price, which indicate that they are a direct replacement for the choseras.
+James Landale I would suggest taking a 120 grit sandpaper, a 400 grit sandpaper and a 1k sandpaper. 120 grit for the fast flattening and 400-1k for polishing out those deep scratches. You could even start with 40 grit sandpaper as long as you polish out those scratches. 1k should be good enough to finish on.
JFYI, you just compared a Chosera against a Chosera of the same grit and found a winner. LOL !!! The professional series Naniwa stones are 100% (CHOLERA STONES) WITHOUT THE BASE) hence, the word (professional). Meaning you have your own sharpening gear and don't need a base. Both stones are produced using the same material, same formula. The only difference is slightly thinner and no base. So basically you get a little less stone and no base with the Professional line, Oh and pay more. However, it's still 100% a Chosera stone. When you said this is a rock. I LOL so hard, for some reason if stuck me right in the funny bone. Now the Naniwa Super Stone is a new line, made using a different formula and different grade of material. However, the Naniwa Professional line is still a 100% a Chosera. This is right from the manufactures mouth. However, you don't even need here it from Naniwa, you can see for yourself. Naniwa changes stone color for every new line that has a change in formula. As you can see these two stone are the same color meaning the same formula. just wanted to point this out. to help those who might not buy a professional stone because of this review. If you like the Chosera you will surely like the Professional as they are the same. However, in the review defense, there are no two stones natural or man made the feel and sharpen the exact same. How I know this = I was looking for a new stone. I noticed the professional line had same color as Chosera stones. so I did my research and found the answer. Just as you can if you need more proof then this. My Bad on only typing errors no time to read over. got to go. have a great day!
Very well said. In addition these stones are light years ahead of the user behind it. Key is practice technique. Rykys video shared that so well and to prove his point I went to sharpen with a brick. Achieving sharp edge. However it’s brick so abrasive compound isn’t good at all. He did it with low Rockwell knife of under 60.
save money? you are too nice. Making more is what i would say, and just looked to rip off the what they think may be ignorant non Japanese people, i hope that is not the case , but i have a hard time trusting, otherwise why is it still in japan, i am upset about this, i am not happy with new one, i know you aren't either
The plastic is alright but if your needing to travel with your stone to bring them to work or whatever it makes it much easier without the plastic stand.
Nice video again! Love the choseras and I got a second choseras 400 before they were replaced by the new series. What type of flattening stone do you use? Need to get one, much more convinient than sandpaper. Is there a way to contact you via email or facebook? Would like to share experience :)
+MrWeedpeet hey, You can contact me via mail on maart510@yahoo.com. I have a naniwa flattening block 220 grit that I use with siliconcarbide powder. The powder is needed to fasten up the process. Without the powder the block will dull and it will take ages for flattening. I now use a diamond sharpening stone (sk-11 150 grit and 600 grit) to give my stones a short flattening after every few uses. It's easy to use and much more easy to clean. For a really concave stone I would still need my flattening block though.
I know this is an older video but I actually chose the professionals so I could use my own base… I much prefer my rubber base and the freedom of a plain stone because I can fit my stone in my drying rack which I could not do with an attached base. Also, the performance is excellent. I also really enjoy the Suehiro Cerax collection (at least for my Japanese knives). I posted this on the response but for anybody reading this a wire drying rack for kitchen plates is the greatest storing/drying solution for your stones that you could ever find for eight dollars.
The Professional series is not available in Japan. The package of your stone has a large "made in Japan" writing in English on its front, so it strongly suggests that the Professional series is launched for western markets. Its color variation to each grit is almost the same as Chosera series, so I think the Professional series is almost the same quality as Chosera series schemed by western dealers for availability.
+virtuovice yes, the quality feels the same. So they will not replace Chosera in Japan, thats interesting. it suggests naniwa is doing the same as shapton with it's professional serie and ha-no-kuromaku series.
stay safe!
+virtuovice yes they are trying to rip us off with a thinner stone.....
virtuovice called Ebi in Japan
i got all my original nainwaa choseras on amazon, so get them befor they may run out their 400 is a pperfect choseraa why they name a different seller is a mystery, but yhe box , numbers , performance and lobster like logo and serial numbers are all their all the other are sold as nainwa, strange but i know although the 400 chosers is named on amazon description as super ceramic is some weird thing i and others have it and find it to be a true chosera
they still sell original japanese chosera and kurumaku on amazon from japan and fast sevice, i am so happy i can still get them and the price is maybe a few dollars more
A sharpening tip: Always keep the three fingers on the blade directly on the stone. This applies an even pressure the full length of the blade and keeps it true. When fingers are off to the side (so fingers are hanging over the edge) the blade touching the stone has less pressure and thus grinds less metal off on that section of blade, over time the results of this incorrect method will become very apparent. So let the blade move freely but keep the fingers on the centre of the stone at all times.
Thank you so much for the video! I was able to find the chosera stones on Amazon and ordered three and a flattening stone.
I miss these videos...
Did Naniwa completely stop production of the older stone with the base and dressing stone?
actually a lot of professional sharpeners don't like those bases and Naniwa has received countless request to get rid of it, you might be upset about that base being gone but so many are jumping for joy, the thinning stones thing is getting really old really quick though the stones are expensive enough but now getting a half to a 3rd of the stone in some cases is really not right at all!
I really didn't like the option to buy without the base, as i have a stone holder i really like and can use over the sink to wash off swarf and wet the stone when needed. I originally liked the bases, but don't like not being able to use both sides
hello, I have been looking into different brands of water stones and have heard a great deal about Shapton and the Naniwa brands. Do you have a preference between the two? what would you suggest?
Thanks,
Travis
+Travis The Jiu-Jitsu Guy funny enough we ourselves use a combination of the two!
Dutch Bushcraft Knives interesting. Would you tell me your stone choices with the two brands? thank you.
Please don't worry because new series comes without a base. Choseras with base look great but they are bulky to handle and I believe there is smaller risk of cracking when stone comes without a base. Thanks for a great video.
Disappointing that they did this, can still get Chosera stones in Canada but they have to be imported. You get so much more stone with the Choseras that it's worth it to me to buy it. Running a few Shapton Ha No Kurumakus 1k 2k 5k and 400 and 3k Chosera. Want to get a Naniwa 8k snow white soon. I think the Chosera stones are beautiful with the markings and the base.
What stones do you use now, and what's grits?
Thanks! =D
I've seen on a few commercial websites that the Chosera line is now limited to Japan only. That pretty much says enough to me. The Professional line is for expert to the barbarians.
But when should i grind a 1000 grit professionals stone
How do you compare Naniwa Pro vs Shapton pro?? Thanks
i like the base also and keeps me from me making a mistake and using the other side i like to keep with one side and flatten
+gunny agreed!
Can you say clearly if the Chosera was better for you? Because from what you say §I understand Chosera is better even if you didn't say directly!!!! I need a the best artificial stone grit 10000 and that's my interest . I found Professional Naniwa is probably the most expensive 10.000 K but not sure! Thanks for your advices!
Is there a benefit with the new stone because now both sides can be used?
Hello, What did you use there for polishing the wet stones?
I wish I could do convex or scandi on my wicked edge. I did try your method on benchmade 162, but I did a garbage job. If anyone can give me advice on how to do those angles on a wicked edge; I’m all ears
I plan to buy professional to reduce risk of cracking. Remember to dry it perpendicular so both sides will dry at the same rate. Otherwise chosera is awesome
The greatest purchase I ever made for my stones was a wire drying rack for plates. I took a pair of wire cutters and cut every other wire to widen the slots. After doing that I can fit six stones and a diamond flattening plate in the rack to dry for as long as needed.
What do you think of Skerper stones. Are they worth it to buy? Thank you master
They are pretty much the same as naniwa specialty stones. Definitely not bad but not for crazy super steels
Thanks a lot!
You have come along way my knife fiend friend
How are these compared to nano hone? And shapton?
reattaching if you can would be great, i like the base and dont have to worry on which side i used and have to flatten, do it and let us know
i've reattached it! I used boiling water to get rid of the chosera remains and used epoxy to glue this stone back on the base.
Completely off subject I know but that is swarf not slurry. ;) (I restore and hone straight razors as a hobby) But yeah, I'll be searching for a Chosera and buying a couple to keep as backups as opposed to buying the new Professional series.
chosera has that confident but not to aggressive sound when sharpening. would you consider a 600 git professional in place of a 400 grit chosera
400-600 very little difference, 800 is what i use to set bevels unless chipped or dinged then i use an atoma 400
im new to waterstones, I just got a king combo stone to try them out. You said that the stone is nearing the end of its life but it looks like most of the stone is still there, how thin can you get them before you have to get a new one?
+West Coast Warriors Archive you can basically use it until you're completely trough the stone as long as you keep the stone flat and flatten it if it becomes concave. This stone was about 3x the height you see here. I still use it but after this winter it's completely worn.
Cheers and good luck with your stones!
Any tips on the very cheapest wetstones ( maybe a combination of wetstones) to make any knife (kitchen and outdoor) hair-shaving sharp? Looking for the absolute budget wetstones.
I wouldn't go more budget than King Stones. check out King stones but don't expect them to sharpen steels like 3v very well
Dutch Bushcraft Knives any budget stones that sharpen all types of steel to a razor edge? (kitchen & outdoor knives)
Dutch Bushcraft Knives any suggestions on budget stones that sharpen any steel well? Not going over 50€
If you still looking the king deluxe stones seem to cut fairly well and the 1200 grit stone is avaiable on amazon for $20 (in the US). The hardest steels that I have (D2, aogami #2 shirogami#2, and CPM-20CV all get sharp on it). If you want something guarenteed to sharpen ANY steel maybe go with diamond plates, EZ-LAP sells some that are at or below $50 but those will be 6 inches by 2 inches
For sharpening a variety of bushcraft and other outdoor knifes, what stones and grits should i choose to be able to reprofile and also get a stable, scary sharp, satin finish mirror grind and egde?
Something like 400 + 5000, something between as well or what? Looking for good value, "low cost, high functionality".
I have the 400 professional stone. Love it.
I was bummed out it not being the Chosera.
But I don't like the base since I use the rubber adj. Base.
Naniwas website claims improved bonding etc.
So it was interesting to watch your video.
The 5k is still a thirsty stone in the series.
I'm gunna skip that stone and get the" snow white" 8k and the pro 3k.
Beautiful edge on that santoku
I might have to ship my knives to Europe to be sharpened ;)
+Big Brown haha, thanks for the comment mate! Snow white isn't the hardest stone but also doesn't take much water. I find the Snow white to be very comfortable. The chosera 3k might be my most favourite stone of all time. It's really like skating on ice with that stone.
Vraagje:
Als mijn keuze zou vallen op een Naniwa steen, welke zou dan het beste geschikt zijn voor “onderhoud” van een mes? Dus machinaal slijpen en tussentijds bijwerken met een wetsteen als een aanzetstaal net tekort komt.
Who in the fuck would write a comment on a US website in fucking German? Now tektort you're fucktard ass out of here.
@@SOS89140 actually it is dutch you ignoramus, and channel is dutch bushcraft knives so.... Blame your parents for raising an igmorant prick
just bought a professional 400 and i having a hard time getting a paper cut edge (very toothy) light or heavy preassure ? never sharpen with water stone before..(was using diamond) thanks
400 grit will always leave toothy edge, which is why they make higher grit stones....
You will need, at the very least, a 1000 grit stone to get that. Realistically you really should be at about 3000 grit.
Hello
Sorry for my English but I'm French . Can I have the name and the model from your plastic boxes in all colors ?
+Sébastien Simon all are shapton ha no kuromaku. 120 grit, 220 grit, 5000 and 12.000
Toishi is the same Choosera?
I guess so
Does anyone know and is sure whether the new Naniwa "Traditional" 8000 is exactly the same as the old "Snow White"?
looks like the export version of the snow white. I think it's the same
thanks, I just wish someone would do a side by side comparison on youtube. Who knows maybe I will do that lol. By the way, I really enjoy your vids guys. keep it up!
Very good!
has good sound, but not like the original, well, i have no choice and just have to deal with it, i hope its new 400grit and others are ok
What about the Naniwa Speciality Stones?
+Loris Buschor they replaced the super stones. I never liked the super stones as they were too soft for my liking
The new stones ARE more expensive... they have increased the price. However they are selling the old choseras at higher prices because they are 5mm larger and in higher demand.
it's a sad story.. really loved those chosera's.
-cheers
I loved mine too, cept my 5k grew cracks all through the stone after about 3 uses. Now my 1k is doing it as well. 400 is still fine. I will never spend another dime on chosera... Naniwa super on the other hand I really enjoy for razors.
Luckily my chosera's don't show cracks. My naniwa snow white does all over the place. I also discovered a crack in my shapton ha-no-kuromaku 5000 stone sadly. I think it's the bonding of these harder stones that cause the cracking.
unless you live in Japan you shouldn't get the ha-no-kuramaku stones... they make the western versions for our climate. A lot of people use the cheaper ones without issues but I would just get the non Japanese version to be safe.
If you want the japanese version, you can get it on ebay. the most cracks due to people who soaks it too long, like cheaper stones. there are splash and go stones, soaking isn't needed
This is the same material, but you get less of this. Plus their save money on the stand too.
This is done by all big companies to make more profit.
I believe the Naniwa Professional line replaces Naniwa Super Stone line, not the Chosera line.
i think the naniwa super is still being sold and cheaper than the professional
ramble on thats the thing its new iphone 7 is more expensive then the 6
the orig chosera with base is best for me. and having good service from japan thru amazon and same old price , generally, and why use shapton pro when you can still gey ha hu kurumaku on amazon, i wont buy for the western market when i can get the rel deal on amazon
The super stones are still super stones, but dealers tend to let you know/call them new super stone... the new pros are the Chosera series’s now. At lease here in US.
There are also a traditional series of stones by Naniwa too.
On the naniwa website, they explain that the professional line is a replacement for the chosera line, along with forums and most other websites that no longer sell choseras, but do still sell the professional, at a lower price, which indicate that they are a direct replacement for the choseras.
If i want to flatten a naniwa 10000 grit super stone with wet sand paper what grit do you revomend i use?
+James Landale I would suggest taking a 120 grit sandpaper, a 400 grit sandpaper and a 1k sandpaper.
120 grit for the fast flattening and 400-1k for polishing out those deep scratches. You could even start with 40 grit sandpaper as long as you polish out those scratches. 1k should be good enough to finish on.
Thankyou for your info. I will give it a try 😎
JFYI, you just compared a Chosera against a Chosera of the same grit and found a winner. LOL !!! The professional series Naniwa stones are 100% (CHOLERA STONES) WITHOUT THE BASE) hence, the word (professional). Meaning you have your own sharpening gear and don't need a base. Both stones are produced using the same material, same formula. The only difference is slightly thinner and no base. So basically you get a little less stone and no base with the Professional line, Oh and pay more. However, it's still 100% a Chosera stone. When you said this is a rock. I LOL so hard, for some reason if stuck me right in the funny bone.
Now the Naniwa Super Stone is a new line, made using a different formula and different grade of material. However, the Naniwa Professional line is still a 100% a Chosera. This is right from the manufactures mouth. However, you don't even need here it from Naniwa, you can see for yourself. Naniwa changes stone color for every new line that has a change in formula. As you can see these two stone are the same color meaning the same formula. just wanted to point this out. to help those who might not buy a professional stone because of this review. If you like the Chosera you will surely like the Professional as they are the same. However, in the review defense, there are no two stones natural or man made the feel and sharpen the exact same. How I know this = I was looking for a new stone. I noticed the professional line had same color as Chosera stones. so I did my research and found the answer. Just as you can if you need more proof then this. My Bad on only typing errors no time to read over. got to go. have a great day!
+troy davis haha i believe you. Thank you for taking the time to share all this information!
Cheers
Very well said. In addition these stones are light years ahead of the user behind it. Key is practice technique.
Rykys video shared that so well and to prove his point I went to sharpen with a brick. Achieving sharp edge. However it’s brick so abrasive compound isn’t good at all. He did it with low Rockwell knife of under 60.
I hope one day I can get some nice quality whetstones to sharpen with, for now, this cheapo smiths tri-hone will do
knife needs repair not sharpening (nice chip)
أريد حجر زيت ناعم..12000النمرة..وشكرا
After watching you video, I really don't give a shit about what you think about them! with all do respect!
+Ramon Donestevez very good
Apparently you do because you took the time to watch and comment ;)
With all due respect I don’t care if you don’t like his opinion! Lmao waste of a comment bro
save money? you are too nice. Making more is what i would say, and just looked to rip off the what they think may be ignorant non Japanese people, i hope that is not the case , but i have a hard time trusting, otherwise why is it still in japan, i am upset about this, i am not happy with new one, i know you aren't either
the plastic is a waist, that's why
WASTE not waist
The plastic is alright but if your needing to travel with your stone to bring them to work or whatever it makes it much easier without the plastic stand.
There sure is folk with some kind of plastic waist right like Nicki Minaj;)
No, very bad!
Nice video again! Love the choseras and I got a second choseras 400 before they were replaced by the new series. What type of flattening stone do you use? Need to get one, much more convinient than sandpaper. Is there a way to contact you via email or facebook? Would like to share experience :)
+MrWeedpeet hey, You can contact me via mail on maart510@yahoo.com. I have a naniwa flattening block 220 grit that I use with siliconcarbide powder. The powder is needed to fasten up the process. Without the powder the block will dull and it will take ages for flattening. I now use a diamond sharpening stone (sk-11 150 grit and 600 grit) to give my stones a short flattening after every few uses. It's easy to use and much more easy to clean. For a really concave stone I would still need my flattening block though.
Honestly, a decent sidewalk is great for doing gross flattening work. Then use a extra coarse diamond stone for fine flattening.
I use an atoma 400, which also doubles as my bevel setter should i need it