# Reinforcing Jnats



## Badgertooth (Apr 23, 2017)

Guide me oh learned ones. I've had advice to go the traditional route of rice paper and lacquer. Any modern twists? I've seen lacquered kite string wrapped around. Any modern more industrial approaches? Something I could pick up at the local hardware rather than order in from Japan?


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## Lazarus (Apr 23, 2017)

I'm not sure if it's sound advise, but my dad dips the bottom half of his oil stones in plasti dip, makes them pretty stout and they have built in grip at that point. Comes off pretty easy with a scraper.


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## KimBronnum (Apr 23, 2017)

I use ship laquer. I know also Maksim uses it. It hardens relatively quickly. 
- Kim


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## cheflivengood (Apr 23, 2017)

I was thinking of trying CA glue and butchers twine but have yet to take the leap.


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## aboynamedsuita (Apr 27, 2017)

Badgertooth said:


> Guide me oh learned ones. I've had advice to go the traditional route of rice paper and lacquer. Any modern twists? I've seen lacquered kite string wrapped around. Any modern more industrial approaches? Something I could pick up at the local hardware rather than order in from Japan?



I've just done the multiple layers of Cashew lacquer, but one stone I recently got from Shinichi was already lacquered and appeared interesting. Unless there was a ton of dust around at the time when the lacquer was applied, it appears to be fiber reinforced, that is to say, there are numerous small fibers which are lacquered over. I may be seeing this as a correlation with fiber reinforced concrete from an engineering standpoint when no correlation exists, but it would presumably increase the strength of the outer layer


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## Anton (Apr 27, 2017)

I don't see how loose strings will give any reinforcement since they are themselves unreinforced/tied to anything. 

I'm may try a piece of high quality mesh tape or joint tape, like what's used on sheet rock and patching.


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## Badgertooth (Apr 27, 2017)

aboynamedsuita said:


> I've just done the multiple layers of Cashew lacquer, but one stone I recently got from Shinichi was already lacquered and appeared interesting. Unless there was a ton of dust around at the time when the lacquer was applied, it appears to be fiber reinforced, that is to say, there are numerous small fibers which are lacquered over. I may be seeing this as a correlation with fiber reinforced concrete from an engineering standpoint when no correlation exists, but it would presumably increase the strength of the outer layer



To be honest, you're on the same track as what I'm going to be trying. My father-in-law has a bunch of boat repair stuff and the chief water resistant patch-em-up is fibreglass tape used to make a composite laminate with epoxy or polyester resins. So basically I'm taking a stone and giving it a tight wrap with some goop to hold it in place.


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## Badgertooth (Apr 27, 2017)

Anton said:


> I don't see how loose strings will give any reinforcement since they are themselves unreinforced/tied to anything.
> 
> I'm may try a piece of high quality mesh tape or joint tape, like what's used on sheet rock and patching.



I think the idea is to glue one end of the string to the side of the stone as an anchor and once it's set you use the side of the stone like a giant rectangular spool for the string. I presume you'd apply a layer of goop to the rest of the side once your anchor is set and wind it round that.

Photo credits thanks to Brooksie


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## malexthekid (Apr 27, 2017)

Anton said:


> I don't see how loose strings will give any reinforcement since they are themselves unreinforced/tied to anything.
> 
> I'm may try a piece of high quality mesh tape or joint tape, like what's used on sheet rock and patching.



Depends what you are trying to achieve. In concrete you fibre reinforce with tiny pieces of steel fibre. The idea being that the fibres span micro cracks as they start to open and prevent them from turning into proper cracks. Provided the fibres have the tensile strength required to prevent the cracks opening.

Its really the same principle as crack control with traditional reinforcing bars.


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## brooksie967 (Apr 28, 2017)

The string is knotted in the corner and wrapped tightly.


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## natto (Apr 30, 2017)

There are cotton fibers and textiles, like glass stuff, to reinforce resin compounds. I like to use them on ugly shapes, tear them into patches. Short cotton fibers can be mixed and painted.

I never reinforced a whetstone, don't know what to do with my cracked slate. Resin compounds are pretty tough and epoxy shrinks 1%, polyester 4%. I don't know much about the traditional way, but something like linseed oil paint and open paper might be a start. The paper used to build model airplanes eventually? Fingerstones?


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## pavel (May 4, 2017)

pavel
Has anyone explored using the fabric and resin used in making orthopedic casts to reinforce and stabjlize jnats ?


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## Badgertooth (May 29, 2017)

Ghetto reinforcement


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## Badgertooth (May 29, 2017)

I am literally willing it to dry so I can test this stone


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## Marek07 (May 29, 2017)

Badgertooth said:


> I am literally willing it to dry so I can test this stone


To twist an old saying... A watched stone never dries!


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## Badgertooth (May 29, 2017)

Yes it does...


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## Marek07 (May 29, 2017)

Badgertooth said:


> Yes it does...



Looks pretty wet from here!
&#128521;


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## natto (May 31, 2017)

I would like a reinforcement that doesn't affect sharpening and gets off with rounding corners.


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## Matus (May 31, 2017)

I have used several (5+) coats of a very thin, milk-like-looking, lacquer from 330_mate from eBay (it came in a small, about 50 ml plastic bottle without any label). That stuff can be dilluted with water, but after drying becomes water resistant. I wanted to buy some more, but he did not have it in stock since quite a while. After drying it is basically color-less. When dilluted to working solution (I used 1:2) it really reminds of mild viscosity-wise, so I rather applied more coats. You can not really see it apart from the stone becoming a little more glossy, though white-ish spots may form on edges7cracks where larger amounts of the lacquer would stick.

I also used it to seal Bester 220, but that stone did soak up quite a bit of it with the first 1-2 coats.


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## spaceconvoy (Oct 5, 2020)

Figured I'd bump this instead of starting a new thread... I have an ocean-mined Tsushima coming my way, and I'm more concerned about long term stability than I'd be for a regular stone. Here are a few interesting solutions I've found elsewhere online:






Washi paper with unknown lacquer, found here - Protecting Natural Sharpening Stones





Linen bookbinding cloth (can be called mull, crash, or tarlatan) with cashew lacquer, found here - 砥石と研ぎ用具 | アーティスト小林健二の道具や技法

Doing some research it seems this is still an area without much information unfortunately. I have a few questions I haven't been able to find answers to:

- When using washi, is it standard practice to wrap around the stone's edges, or cut individual pieces for each side similar to the example above? Could be mostly decorative, or maybe wrapping the edges is unnecessary and worse for longevity due to wear and potential fraying.

- In theory, is it better to have the larger surface area of the washi, or the higher strength of cloth mesh/wrapped string?

- How has the string held up over time, @Badgertooth or @brooksie967? I'm curious if you've had to remove any layers while flattening, and if so, how much of a mess it was.

- Is reinforcement overkill for a stone with no visible cracks? Maybe dealing with water intrusion and evaporation the biggest factor, and a few coats of varnish/urethane is good enough. Will I see problems slowly appear or should I go for overkill now to prevent unforeseen catastrophic cracking?

If my stone wasn't from an underwater mine I wouldn't be so worried about it. But then again, my family is catholic so unnecessary worry gives my life meaning.


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## Badgertooth (Oct 9, 2020)

Some food for thought in that post. And auspicious timing too. As I have literally just come from a friend’s house where we are reinforcing a stone with twine which has a crack appearing in it.
Your available methods are as follows

1. *Twine and lacquer/resin/cashew*
Leave a little quarter to half inch headroom between your lapped surface and the twine and you’ll likely never reach it. I am no closer to the twine on the one in the post than when I did the post.

2. *Glass cloth and resin* 
Basically makes a see-through fibreglass encasement. It’s a pain in the derrière to do but very effective. If you chamfer the edges regularly, it will grow with you.

3. *Paper and lacquer*
My most recent kick. Use a bit of wood glue to get it to stick before saturating with lacquer and applying subsequent layers. The paper is hand printed chiyogami. 










spaceconvoy said:


> Figured I'd bump this instead of starting a new thread... I have an ocean-mined Tsushima coming my way, and I'm more concerned about long term stability than I'd be for a regular stone. Here are a few interesting solutions I've found elsewhere online:
> 
> View attachment 97500
> 
> ...


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## KO88 (Oct 9, 2020)

KimBronnum said:


> I use ship laquer. I know also Maksim uses it. It hardens relatively quickly.
> - Kim




I use it too and works pefect...


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## spaceconvoy (Oct 11, 2020)

I went with what was easy to source from amazon, not sure how optimal they are, but most people suggest it doesn't matter a whole lot. I like this mulberry paper, it's thin but not too thin, and the fibers are nicely tangled together. You can kinda see how well it stretched around the chunk that was taken out of it (I'm guessing that was part of Shinichi's hardness testing?)

I've been building up coats, sanded with 1500 grit sandpaper in between. The paper seemed to absorb the first two coats, and I'll keep going until I can't feel the paper edges at the corners. At five now, and at least one more. I went with the water-based urethane just cause oil-based didn't seem good for a stone, but I don't think it actually matters.

Edit: forgot to mention that before spraying I joined them together with some acid-free spray adhesive I had lying around. It was much easier than I expected, no bubbles or creases. Might be this particular paper, since it's nice and stretchy.


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## waxy (Oct 14, 2020)

Question about all the reinforcement on the JNats, are they naturally flattened out or do they get pre-staged before sharpening?
I have a few JNats I bought and it's getting close to the protective layer.

Thanks in advance!


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## Badgertooth (Oct 14, 2020)

spaceconvoy said:


> View attachment 98258
> View attachment 98259
> 
> I went with what was easy to source from amazon, not sure how optimal they are, but most people suggest it doesn't matter a whole lot. I like this mulberry paper, it's thin but not too thin, and the fibers are nicely tangled together. You can kinda see how well it stretched around the chunk that was taken out of it (I'm guessing that was part of Shinichi's hardness testing?)
> ...


How’s the reinforcement of this one going?


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## Badgertooth (Oct 14, 2020)

C


waxy said:


> Question about all the reinforcement on the JNats, are they naturally flattened out or do they get pre-staged before sharpening?
> I have a few JNats I bought and it's getting close to the protective layer.
> 
> Thanks in advance!


You need to flatten yourself and judiciously maintain a chamfer as you eventually get nearer protective reinforcements.


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## spaceconvoy (Oct 14, 2020)

Badgertooth said:


> How’s the reinforcement of this one going?


Good timing, I was just about to post. I ended up going with six coats and let it dry for 72 hours. Unfortunately when I used it just now the paper soaked up some water. I tried to work quickly and use only a minimal amount of water. Here's how it looked right after using it:







After drying it seems fine now, but the places that got wet have a slightly different surface texture, more matted. I don't know what to make of it exactly. Is this:
- normal and to be expected
- used the wrong lacquer
- not enough coats
- didn't wait long enough to cure
- other ??


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## waxy (Oct 15, 2020)

Badgertooth said:


> C
> 
> You need to flatten yourself and judiciously maintain a chamfer as you eventually get nearer protective reinforcements.



Thank you for your response, I would assume a diamond flattening stone to create those chamfers.


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## DHunter86 (Oct 15, 2020)

Can be done with SiC powder on a flat tile or piece of glass as well.


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## DHunter86 (Oct 15, 2020)

spaceconvoy said:


> Good timing, I was just about to post. I ended up going with six coats and let it dry for 72 hours. Unfortunately when I used it just now the paper soaked up some water. I tried to work quickly and use only a minimal amount of water. Here's how it looked right after using it:
> View attachment 98789
> View attachment 98790
> 
> ...



From my limited experience, it seems that the fibers of the paper weren't fully saturated with the lacquer.


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## spaceconvoy (Oct 15, 2020)

DHunter86 said:


> From my limited experience, it seems that the fibers of the paper weren't fully saturated with the lacquer.


That makes sense... probably used too thick a paper. Looks like I'll have to sand it down and try again, maybe just skip the paper next time.


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## DHunter86 (Oct 15, 2020)

Or maybe try with a thicker coat of lacquer?


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## spaceconvoy (Oct 15, 2020)

I imagine adding more coats of this spray-on urethane won't saturate the paper any further. Maybe if I bought a paint-on lacquer so I could apply it thicker.


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## DHunter86 (Oct 15, 2020)

Possibly. I've been using paint on lacquer and found it easy to saturate any paper. Although I didn't like the yellowish tint it gave on some whiter stones, it's been doing its job.


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## Badgertooth (Oct 15, 2020)

spaceconvoy said:


> I imagine adding more coats of this spray-on urethane won't saturate the paper any further. Maybe if I bought a paint-on lacquer so I could apply it thicker.


Get a paint on lacquer, thin it judiciously to decrease the viscosity for the first 4 or 5 layers then leave it thicker once it’s reached a saturation point.


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