# Stone req for thinning?



## aszma (Nov 4, 2020)

Looking for a low grit stone I can use to thin some of my knives as two are starting to wedge. Originally I was going to do it on a 1000 grit stone but I was recommended not too as it might take a while. Budget id like to keep it under 150USD and if anyone could shoot me some youtube videos as well ( I looked up myself but theres a lot of information on the internet and im not sure which one would be best to follow for someone whos never done this ). The knife im going to thin is a stainless clad blue #2 gyuto if that matters. Thank you.

BC i dont want to make several posts id also like to learn to polish my knives and give a mirror finish are there any guides good guides and equipment id need to do so?


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## JDC (Nov 4, 2020)

I love efficiency and anti-dishing, so my choices are diamond stones for low grits, specifically this stone: 
DMT WM8CX 8-Inch DuoSharp Plus Bench Stone Coarse / Extra-Coarse

I follow it with Shapton pro 1000, which erases the "coarse" scratches effectively.


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## M1k3 (Nov 4, 2020)

Sigma 240 followed by Shapton Glass 500.


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## Alder26 (Nov 4, 2020)

Shapton glass 220 or 320 are a good choice as well


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## inferno (Nov 4, 2020)

aszma said:


> Looking for a low grit stone I can use to thin some of my knives as two are starting to wedge. Originally I was going to do it on a 1000 grit stone but I was recommended not too as it might take a while. Budget id like to keep it under 150USD and if anyone could shoot me some youtube videos as well ( I looked up myself but theres a lot of information on the internet and im not sure which one would be best to follow for someone whos never done this ). The knife im going to thin is a stainless clad blue #2 gyuto if that matters. Thank you.
> 
> BC i dont want to make several posts id also like to learn to polish my knives and give a mirror finish are there any guides good guides and equipment id need to do so?



have you tried doing it on your 1k first?? i think you should try it with what you have.
its after you tried it and got tired of it you really need a coarser stone.

other than that, glass/pro 220 works and so does glass 500.


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## inferno (Nov 4, 2020)

M1k3 said:


> Sigma 240 followed by Shapton Glass 500.



how do you like the 240 sigma?? 

i think its too thirsty and the scratches are too deep. i think the shaptons are just as fast or faster and the scratches are much smoother and faster to erase.


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## M1k3 (Nov 4, 2020)

inferno said:


> how do you like the 240 sigma??
> 
> i think its too thirsty and the scratches are too deep. i think the shaptons are just as fast or faster and the scratches are much smoother and faster to erase.


I leave it muddy. Adding small amounts of water. I don't find the scratches to deep. Maybe because I let the mud build up?
I like it, it just keeps working while not dishing overly fast.


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## jwthaparc (Nov 4, 2020)

Do you just want a mirror finish on the core steel, or both the core and the cladding?


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## Unstoppabo (Nov 4, 2020)

Check out JKI's youtube videos on thinning. $150 goes a long way with low grit stones. I don't like flattening soft, low grit stones so I usually stick with Shapton glass 500 unless I'm really trying to change geometry but have thought about getting a SP 320 in the past. Even if you buy both, you should still have enough left over for a ton of wet/dry sand paper. Get a full progression up to like 5k if you want to get the SS cladding close to mirror. Cut pieces to fit a nice flat benchstone and slap the sand paper right on top. The grit from the stone is more than enough to keep the sand paper in place.


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## Benuser (Nov 5, 2020)

What knife is it you want to give a mirror finish? Quite some stainless cladding are soft — for a good reason: to protect the core of breaking. Get very easily scratched with use. The good news is scratches get easily removed as well. A mirror finish though is a lot of work, makes it extremely vulnerable and may lead to food sticking.


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## M1k3 (Nov 5, 2020)

Benuser said:


> What knife is it you want to give a mirror finish? Quite some stainless cladding are soft — for a good reason: to protect the core of breaking. Get very easily scratched with use. The good news is scratches get easily removed as well. A mirror finish though is a lot of work, makes it extremely vulnerable and may lead to food sticking.


Mirror finishes so scratches off better also.


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## aszma (Nov 5, 2020)

inferno said:


> have you tried doing it on your 1k first?? i think you should try it with what you have.
> its after you tried it and got tired of it you really need a coarser stone.
> 
> other than that, glass/pro 220 works and so does glass 500.


That was the original plan but a friend told me that it would be a huge ***** to do on a 1000 plus this kills two birds with one stone as ive been wanted to get a lower grit stone anyways. I do all the sharpening and knife fixing at my work place and these guys chip knives like crazy and im sick of fixing their chips on my 1000


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## aszma (Nov 5, 2020)

M1k3 said:


> Sigma 240 followed by Shapton Glass 500.
> [/
> 
> 
> ...


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## aszma (Nov 5, 2020)

jwthaparc said:


> Do you just want a mirror finish on the core steel, or both the core and the cladding?


both


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## aszma (Nov 5, 2020)

M1k3 said:


> Sigma 240 followed by Shapton Glass 500.


Would just one of these stones work or is there a huge difference when starting on a 240 then a 500?


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## jwthaparc (Nov 5, 2020)

aszma said:


> both


Ok, sandpaper might be your best bet then. Whetstones are going to tend to add a kasumi finish to the softer cladding in my experience.


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## jacko9 (Nov 5, 2020)

Unstoppabo said:


> Check out JKI's youtube videos on thinning. $150 goes a long way with low grit stones. I don't like flattening soft, low grit stones so I usually stick with Shapton glass 500 unless I'm really trying to change geometry but have thought about getting a SP 320 in the past. Even if you buy both, you should still have enough left over for a ton of wet/dry sand paper. Get a full progression up to like 5k if you want to get the SS cladding close to mirror. Cut pieces to fit a nice flat benchstone and slap the sand paper right on top. The grit from the stone is more than enough to keep the sand paper in place.



My Shapton Pro 320 is not a very fast cutter about the same as my Shapton Glass 500. I went and bought a Nubatama 180 Bamboo Black that will cut really fast and then go to my Shapton Glass 500 or my Shapton Glass 1000.


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## Runner_up (Nov 5, 2020)

I really like the shapton glass 320. Much better than the regular pro at that grit.


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## Slim278 (Nov 5, 2020)

I like the CERAX #320 I have. I think an inexpensive Norton Crystolon or similar stone would work well for thinning and you wont have to worry about dishing with them.


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## M1k3 (Nov 5, 2020)

aszma said:


> Would just one of these stones work or is there a huge difference when starting on a 240 then a 500?


The 500 would be fine for smaller chips and lighter thinning. Definitely faster than the 1k. The 240 or whatever lower stone you decide on, would be faster at the small chips (time is money) and good for more intense metal removal.


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## adrianopedro (Nov 5, 2020)

Suehiro Debado 200 is an great option for thinning and bevel flattening, fast cutter, not much dishing. You can follow it with Naniwa Chosera 400 for scratches removal.
Heard great things about nanohone 200 too


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## aszma (Nov 6, 2020)

jwthaparc said:


> Ok, sandpaper might be your best bet then. Whetstones are going to tend to add a kasumi finish to the softer cladding in my experience.


What grits would your recommend for me to get for sandpaper?


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## jwthaparc (Nov 6, 2020)

aszma said:


> What grits would your recommend for me to get for sandpaper?


It depends how deep the scratches are. 120, or 80 for really deep scratches, then go 150, 200, 250, 300, 400, 500, 600 (you can start around 400-600 if the surface doesn't really have scratches that need to be removed) then go from 700-1000, 1200, 1500, 2000, 2500, 3000 then maybe switch to a polishing compound, I personally go all the way up to around 7000-8000 if I really want a mirror finish. It's a lot of work.


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## Leo Barr (Nov 6, 2020)

Not really convinced that too low a grit is that effective for thinning since a lot of lower grit stones are quite soft. I had a big thinning job on a stick I tried some of the lower grits including sprinkling silicon carbide crystals on to them to start with but I think somewhere around a 320 I have a Nubatama Platinum which is hard a cuts well it felt like worked then went etc slowly upwards 400-600-1K I thinned it to a point where I felt it was acceptable it the maker had given it the profile of an axe although it was meant to be a sujihiki plus he had ground more out of the middle part of the knife I & the steel felt like it had not been toughened . The next sharpening should make it a half descent knife but if it is dropped it will chip it was handed to me with a broken tip.
In normal situations the courses grit I would use is 320 normally if the knife is half descent I will thin down to the edge with a 600.


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## inferno (Nov 6, 2020)

there definitely seems to be a relationship with speed/wear/hardness etc.
the coarser the stones the faster.
the coarser the softer.
the faster they are the faster they wear.

there are a few stones behave a little different though. for example i have read that the jns 300 and king gray 300 wear slow. but they're not very fast stones.

i've had good luck with the shapton pro 220 and glass 220. they they wear kinda fast if you want them work fast. but i feel the tradeoff is worth it. you get a lot done. the glass 500 is definitely slower but it also wears much slower. my imanishi 400 blue is not super fast but it wears very fast. it creates a slurry that hides subpar grinds in like 2 seconds.

basically all coarse stones are compromises. you just have to choose which ones are acceptable to you.


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## Staystrapped (Nov 6, 2020)

Are diamonds out of the discussion?


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## aszma (Nov 6, 2020)

Staystrapped said:


> Are diamonds out of the discussion?


They are not if they work im open to all suggestions


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## jwthaparc (Nov 6, 2020)

aszma said:


> They are not if they work im open to all suggestions


Diamonds are great. I used an atoma 140 to regrind a gyuto (not reprofile, I actually reground the whole knife) and for doing something like that by hand it was actually relatively fast. I pretty much KO'd that plate though, but that is way more wear than a normal person would put on it in that amount of time.

I'll edit this with a link to the images to show exactly how much work I'm talking about doing by hand.


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## Staystrapped (Nov 6, 2020)

This guy blasts a yanagi on a shapton 120 and atoma 140 pretty interesting


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## inferno (Nov 6, 2020)

the problem with diamonds is that you wear them out very fast when thinning blades.


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## inferno (Nov 7, 2020)

hey guys i just tested out a stone that i had lent to a coworker.
its an "indiga" (its a german india copy) dual stone, C/F.

so i lapped the C side with 120SiC powder and the fine with a d-plate. the coarse side felt very coarse and aggressive.
put a stainless mora on there and basically nothing happens. it scratches the surface a bit, but thats it. its so slow i'd rather be sharpening on a brick.

its very hard and slow wearing. but its too hard, and wears too little, so after like 30 seconds when the abrasive is blunted no new abrasive ever gets exposed. basically the stone is a complete fail for knives. maybe good for machine tools or whatever it now was designed for??

so imo if you want to remove some metal with a coarse stone. make sure it release at least some abrasive.

now for the fine side. its just the same. i think its a 240 or 320 or even 400 by design but it felt like 1500 or so. and whats happening is that i basically fill up the pores in the stone around the abrasives until the stone turns dark, and then it stops cutting. because there is no new abrasive getting exposed. and this takes about 1 minute.

avoid ****** stones! they are not worth the time spent even if they're for free.


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## M1k3 (Nov 7, 2020)

Try some wd-40 on them.


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## dafox (Nov 27, 2020)

Here is an interesting video with a stone progression for thinning a Mazaki:


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