J-Nat sealing question.

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Currantly

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Hey KKF!

I’ve got a question about sealing a Japanese natural stone. I did some research on the site and know there’s a lot of different methods to achieve this. I was wondering if there’s anyone out there who seals stones for commission.

I really don’t have the confidence or space to do so myself, so any information on a lead would be great. I just recently purchased a Tanaka Toishi Aoto (I’ll show a photo) and I would really love to get it sealed before using. Looking forward to hearing from you all. Thank you!

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Nagakin

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I don’t know of any sealing services, but do have some tips that might make you more confident about doing it yourself. You don't need extra space, just somewhere to leave it where you won't be breathing in fumes all day. Right outside is fine.

Mask the sharpening surface and really press down with something rounded so you don't gouge the tape. Use something that dries quick and apply thin coats with a brush. If you lay the stone face down on something flat you'll avoid any drip this way.

If you're still worried, you also don't have to seal the entire stone at once. Just seal the sides first with your masked surface facing up and do the bottom afterwards for zero chance of drippage.

Tbh, even if you do get some sealant on your sharpening surface it's not a huge deal. Just let it dry and hit it with your diamond plate. Don't try to wash it or wipe it off with water or you'll just spread it out. You won't do be able to do any real harm without intending to, so it's worth a try.
 

inferno

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i usually just tape up the surface i dont want sealed, turn the stone up side down, and then spray paint it with clear coat. done.
 

GoodMagic

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What Inferno said. I have used spray on and it works fine. Usually three coats or more. I don’t think you even need to use shellac or lacquer, I’ve used spray on acrylic clear and seems to work fine and is easy to clean. Use masking tape on the top of the stone, I use blue painters tape.
 

Currantly

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Thanks for all the tips guys! I think with a little confidence I should totally be able to do it myself. Any recommend brand of clear you all use?
I was reading cashew laquer is traditional (but damn near impossible to find). I saw a site called “earth-paint” that’s supposedly cashew based. Any thoughts on that as well?
 

Fynbo

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I use a can of lacquer spray paint from the local hardware store. Cover the sharpening surface with painters tape.
 

Matus

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I used acrylic lacquer in a spray form on several synthetic stones that I permasoak. 3 coats (always allowing the previous to dry first) sealed the stones 100% and the coat appears to be perfectly water resistant. Super easy yo apply too.
 

PotterMcMuck

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Because I'm interested in the more traditional ways of doing things, I sealed my most recent stones with urushi, which is what was used before cashew lacquer came along. It's remarkably easy to work with - the hardest part is finding the stuff. It works the same as cashew lacquer, you just need to dilute it with artist grade turpentine in order to apply thin coats. The only real trick is that it needs to be in a warm and humid place in order for the urushi to cure properly. If the curing conditions aren't good, including if you've used subpar turpentine, a coat can take weeks to cure instead of a day (I speak from experience). Overall, it was way easier than I expected.

I've also sealed stones with spray on stuff, which works well. I've also used clear nail polish, which worked ok - I wouldn't really recommend it unless you're looking for a really cheap, temporary solution.

As mentioned, just cover the honing surface with something like painters tape. Don't worry too much about making a mess, you'll need to lap it before use anyways.
 

Currantly

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Answers like these are exactly why I love this community. Thank you everyone for the input, I’ve got a few ideas about how I’m going to attack this now.
 

Currantly

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Because I'm interested in the more traditional ways of doing things, I sealed my most recent stones with urushi, which is what was used before cashew lacquer came along. It's remarkably easy to work with - the hardest part is finding the stuff. It works the same as cashew lacquer, you just need to dilute it with artist grade turpentine in order to apply thin coats. The only real trick is that it needs to be in a warm and humid place in order for the urushi to cure properly. If the curing conditions aren't good, including if you've used subpar turpentine, a coat can take weeks to cure instead of a day (I speak from experience). Overall, it was way easier than I expected.

I've also sealed stones with spray on stuff, which works well. I've also used clear nail polish, which worked ok - I wouldn't really recommend it unless you're looking for a really cheap, temporary solution.

As mentioned, just cover the honing surface with something like painters tape. Don't worry too much about making a mess, you'll need to lap it before use anyways.
I’m always interested in doing things the traditional way, that’s why I wanted to find cashew lacquer for my stones. But it seems damn near impossible to find here in the states.
I haven’t heard of urushi before but I’m going to do a little reading on it tonight, maybe I’ll luck out and find some if I decide to take that path.
 

Currantly

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I used acrylic lacquer in a spray form on several synthetic stones that I permasoak. 3 coats (always allowing the previous to dry first) sealed the stones 100% and the coat appears to be perfectly water resistant. Super easy yo apply too.
Any particular brand that you’ve had success with? I noticed @D J mentioned about it being “food safe”.
 
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I was once a advocate for clear spray on shellac to seal stones. I have since gotten away from this because if you soak your stones for a period of time the coating will discolor and take on a gray dingy look. I have some stones with a great visual appearance and this soiled them.
Spray on sealant is easily removed by soaking the stones in denatured alcohol and scrubbing off.
+1 for urushi
 

D J

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Cashew and urushi are not available in Australia and the few attempts to get seller's to send it has not succeeded, due to hazardous or flammable goods not able to be sent...by mail.
 

Matus

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Any particular brand that you’ve had success with? I noticed @D J mentioned about it being “food safe”.
I don’t really care about food safety since not only there is very little of the lacquer that is being removed from the stone when sharpening, but you wash all the mud off before using the knife anyhow. I doubt that the stones themselves are particularly food safe.

I have used the lacquer by Edding. 3 (or 4?) coats created completely smooth (slippery when wet) surface on my JNS800 and I see absolutely no degradation after 1 year of permasoaking.

I have used some white-is ‘lacquer’ for natural stones before (I got it from some eBay seller - possibly metalmaster) and that one degraded and caused brown spots after year or two on my Gesshin Synthetic Natural - I may strip it off and re-coat with the Edding.
 

Fynbo

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I'm not concerned with the food safety of any lacquer. I always round the edges of the stones a little, the knife is never in contact with it.
I sealed this stone summer 2019 with a 10$ spray paint and it hold up fine. Its never soaked just splash and go.
Instructions said the paint can be used on wood, metal, stone, glass ect.

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PotterMcMuck

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I’m always interested in doing things the traditional way, that’s why I wanted to find cashew lacquer for my stones. But it seems damn near impossible to find here in the states.
I haven’t heard of urushi before but I’m going to do a little reading on it tonight, maybe I’ll luck out and find some if I decide to take that path.
It was really tough to find either urushi or cashew lacquer in Canada. In my search, I found a few places in the US, but because it wasn't relevant to me because of the problems with shipping, I didn't bother making notes. I have a feeling Keith Johnson (tomonagura.com) might sell cashew lacquer through his Etsy shop, but I might be wrong.

In the end, I found urushi through a Kintsugi artist in Toronto who imports various kinds from Japan. Before contacting him, I had no idea there was more than one kind of urushi, but apparently there are different kinds for different materials. He happened to have some toishi urushi on hand, so I lucked out.

I'm not suggesting you buy from him, because of the potential problems getting it over the border. But Kintsugi artists might be another avenue you can pursue if you want to search for urushi locally, or at least within your own country.
 
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