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Jnat: Lap then seal? Or seal then lap? Other random questions…

I apologize for another dumb question, I just can’t seem to find the correct answer. I’m probably over thinking things but I can’t help the OCD.

I finally got my cashew lacquer in the mail, and some spare time to seal my first Jnat. I’m a little stumped on what order to do this though.

Should I lap the stone first then seal it? If that’s the case, how long should I wait to let it dry before sealing? Any guidance is appreciated, or if someone has a good resource to read up on the order of doing things, I can’t seem to find the answer.

Side question: anyone ever repaint the stamps on a Jnat after lapping them off? I’m thinking about using a fine paint brush to add them to the sides of the stone before I add on the lacquer. It will serve no purpose other than aesthetics- dumb idea?

Lastly, I could only get “black” cashew lacquer, does anyone use that? I’m sure there is no difference other than color, just curious to see others’ experiences.

Thanks in advance, appreciate you guys!
 
Honestly, If I were doing it I'd seal the stone with a clear sealant... And photo/print and then seal over a picture of the original stamps on the side rather than trying to paint them myself... if it were me.

As it is, I've only ever sealed one stone myself... And it was cause it was cracking... and I used dollar store nail polish... so I'm certainly not the best to answer your questions. @Gamma ?
 
Honestly, If I were doing it I'd seal the stone with a clear sealant... And photo/print and then seal over a picture of the original stamps on the side rather than trying to paint them myself... if it were me.

As it is, I've only ever sealed one stone myself... And it was cause it was cracking... and I used dollar store nail polish... so I'm certainly not the best to answer your questions. @Gamma ?
Interesting idea. I thought about doing the backside but it is pretty rough. I wasn’t planning on lapping that side because it would take forever and wear down my Diamond plate.

What’s faster than a Diamond plate that I could use on the backside, because I like your idea.
 
Dont lap the backside... The natural "Skin" or whatever they call it is really important to some Jnat guys.

Maybe laminate a card with the original picture and store it with the stone instead if no side is flat enough?
 
Think it will make some stones harder to sell but I like the black finish. You do want to take photos before though so any future buyers (if you do sell) can see what is going on. You can also lap the corners some though to reduce chance of bumps hurting the stone. My stone from aframes came sealed with the edges having this treatment. 16748341336576955216966788757349.jpg
 
Dont lap the backside... The natural "Skin" or whatever they call it is really important to some Jnat guys.

Maybe laminate a card with the original picture and store it with the stone instead if no side is flat enough?
Thanks for the heads up! I guess I’ll just see what I’m feeling when the time comes, I’ll probably be too lazy to do anything after lapping it anyways lol. I’ll post some pictures if I end up doing something like that.
 
Think it will make some stones harder to sell but I like the black finish. You do want to take photos before though so any future buyers (if you do sell) can see what is going on. You can also lap the corners some though to reduce chance of bumps hurting the stone. My stone from aframes came sealed with the edges having this treatment. View attachment 1595327
That looks great, thanks for sharing!
 
I always seal first before lapping, because the stone gets thoroughly soaked while lapping and that’s what can cause cracking. Plus, some sealant might seep under the edges of the tape you’ll be putting on the working surface which will need to be lapped off anyway.

I opt for a translucent sealer. A black sealer will hide all of the parts of the stone that future buyers/enthusiasts will want to see and admire.

I personally would not repaint the stamps or kanji after lapping them off. That gives me “fake Maruka stamp” vibes, which drive more people away than having no stamp at all.
 
I always seal first before lapping, because the stone gets thoroughly soaked while lapping and that’s what can cause cracking. Plus, some sealant might seep under the edges of the tape you’ll be putting on the working surface which will need to be lapped off anyway.

I opt for a translucent sealer. A black sealer will hide all of the parts of the stone that future buyers/enthusiasts will want to see and admire.

I personally would not repaint the stamps or kanji after lapping them off. That gives me “fake Maruka stamp” vibes, which drive more people away than having no stamp at all.
Awesome info, thank you! Yeah I wish I coulda got my hands on some translucent cashew lacquer, but I got impatient so I’m kinda stuck with the dark stuff. Honestly though, I kinda like the look of darker lacquer so I’m not too worried. No plans to sell anytime soon lol. Thanks again!
 
I have only sealed a few of my Jnats, the rest have gone unsealed for years, without issue.

Yes, seal then lap. I used water based clear craft varnish. Dries quickly, easy to find and inexpensive.

I do not do an excessive bevel, just a small bevel on the face, more like rounding.

If you needed to lap off a lot of material, use loose Silicone Carbide or Diamond powder and a cookie sheet. A Silicone Carbide stone works well also.

If your stone back is not flat, glue on pieces of craft foam or yoga mat, or dabs of silicone, so it will sit flat on a rubber holder.
 
I have only sealed a few of my Jnats, the rest have gone unsealed for years, without issue.

Yes, seal then lap. I used water based clear craft varnish. Dries quickly, easy to find and inexpensive.

I do not do an excessive bevel, just a small bevel on the face, more like rounding.

If you needed to lap off a lot of material, use loose Silicone Carbide or Diamond powder and a cookie sheet. A Silicone Carbide stone works well also.

If your stone back is not flat, glue on pieces of craft foam or yoga mat, or dabs of silicone, so it will sit flat on a rubber holder.
Fantastic stuff here, thanks so much! I’m going to look into Diamond powder, I’ve heard of this but never looked into it, as I haven’t seen many people talk about it.

I’m seeing silicone carbide powder on Amazon, might go that route. Home Depot has “Diamond dust” however I’m guessing that’s not the same as it’s for adding sparkles to things lol
 
I buy Silicone Carbide from Got Grit.com. $15 will get you a progression from 60 to 500 grit.

60 grit is the work horse. Jnats lap easily compared to Novaculite.

I buy Diamond Powder from eBay, (Tec Diamond Tool) here again 60 grit is the one you want, it too is not expensive you only need a little, what you can pick up from a wooden coffee stir stick, add more as needed.
 
I buy Silicone Carbide from Got Grit.com. $15 will get you a progression from 60 to 500 grit.

60 grit is the work horse. Jnats lap easily compared to Novaculite.

I buy Diamond Powder from eBay, (Tec Diamond Tool) here again 60 grit is the one you want, it too is not expensive you only need a little, what you can pick up from a wooden coffee stir stick, add more as needed.
You’re the man, thank you!
 

Steve56

Ask me about shaving naked!
It doesn’t matter what prder that you lap/seal in, just as long as the stone is dry when you apply the lacquer. 24h is usually sufficient. If it isn’t really dry when you coat the stone, you can get little bubbles as the water evaporates out of the stone.

Usually you get a little lacquer on the surface and have to re-lap it anyway, or at least I do, so seal then lap works well, especially since you have to chamfer the edges and corners of the face.

I use the black a lot depending on the color of the stone. A yellow (kiita) stone looks very impressive with black lacquer on the sides.

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There really is no need to lap any Jnat with SIC. I recommend not using it on stones like that, the stuff is friable and can embed into the stone which can be problematic. If it gets in far enough, it will be a long while before the stones finishing qualities are realized.
Honestly, there is just no need for it - 220x w/d paper works fine. Save the SIC for Arks and Washita and similar.

For sealing - it's your stone so do what you like. I don't use solid color lacquer usually because that is what unscrupulous people use to hide cracks in the sides. Sometimes it's done to cover a glued fissure though, so the visual is nicer. Sometimes a Washi wrap is added for adding strength to weak or problematic stones. Whatever the case, it makes me uneasy when I see an expensive stone sealed in opaque lacquer. Honestly, 99.9% of the time - I would rather use clear nail polish than Opaque Cashew. The solid color Cashew is weaker than the transparent type, so there's that.
When nail polish is diluted well enough for the first few applications, it will creep into the stone deep enough to make both a good seal and added strength. Just applying something 'on top' will help prevent water ingress but it won't do anything else. It's called 'sealing' but the process is designed to be much more than just that.

I would not recommend trying to 'paint' stamps back on. There are enough stones with fake stamps out there as it is.
Photograph them, save them, if you ever go to sell you have the stamps to show.
 

Legion

Staff member
I think the black/clear argument depends on whether the individual stone has features on the sides that need showing off. If not, black would be fine.

I wouldn't hand paint the stamps back on. That would look sketchy, like you were trying to fabricate something. Just take lots of clear photos before you remove them.

I've lapped then sealed. One or two soakings shouldn't cause issues, and you will know exactly where the surface and chamfers are going to be when painting on the lacquer.


I've never used cashew lacquer, but clear slate floor sealant is practically purpose made for the task.
 

Steve56

Ask me about shaving naked!
I've never used cashew lacquer, but clear slate floor sealant is practically purpose made for the task.

Tile sealant is great, functionally. The best alternative to cashew that I’ve found is just plain old marine spar varnish.

It’s clearer than cashew, has a similar (but a little less) gloss, and if the stone has colors that I want to preserve, marine spar varnish is the choice.

Spar varnish is also good for finishing wooden hone bases. You can adjust the finish appearance with fine sandpaper, steel (or bronze) wool, various abrasive polishes, waxes , etc.
 
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Craziest seal is that biniroze. The Tsushima I have is sealed in Kermit the frog green biniroze paint. It's vinyl based afaik
 
Just my personal feelings……

Use the stone a few times before sealing it. It gives you a feeling of what you want to do and what you expect to see when the sealing is finished.

I was on a cashew kick years ago but then they came out with a newer clearer urushi (varnish?) that is spray on. Costs more but it’s all around better IMHO.

PLEASE practice on a practice stone first. There is a learning curve with cashew.

Do it outside. It finds a way to get messy, and it gets really messy.

You might need to use some thinner to get a good consistency. Looks better thin but then it tends to run like crazy. Runs probably don’t matter as much with the black.

Use painters tape on all surfaces you don’t want cashew on. Personally I run a line of tape all around about 3 mm down from the sharpening surface then I fold that in and cover the rest of the surface.

Have somewhere to store the stone outside. Cashew wreaks of cat urine for about a week before it fully dries.

Personally I like to scrub my stones with Barkeepers Friend to get the surfaces as clean as possible before coving with clear varnish. This makes them look really good. I have a vintage Maruka and the stamp came out looking even better. I have a new-age Maruka and the stamp almost instantly disappeared. YMMV, but cleaned stone and clear lacquer can have a very beautiful effect.
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