Thread: Sealing a J-nat

I have a J-nat which I bought unsealed. It may be my imagination but I think I see a crack developing so I want to seal it. I have read some posts about cashew /urushi lacquer and whilst I appreciate that this is the traditional way to go I wondered what would be an acceptable alternative that would be more readilly available.

Thanks
Claude

I use water resistant vinil glue, inexpensive but a good solution, it take some days to completely dry, but it's inexpensive and effective

Regards
Luca

Originally Posted by kairen

I use water resistant vinil glue, inexpensive but a good solution, it take some days to completely dry, but it's inexpensive and effective

Regards
Luca

Thanks. Would a clear epoxy glue be suitable?

You can use a spray can of automotive clear coat or any clear that is an alkyd ester.
Water resistant & tuff but slippery when wet.
Just put the stone face down on a cloth to prevent runs onto the work surface. A few quick sprays & you're done.

You can also use your wife's clear nail polish. Just don't let her catch you.

I've actually never understood it. I always thought the sealant was to protect the stamps.

After-all it's a rock and putting a coat of whatever on will not stop a crack. Most start internally anyway.

I use shellac and it works just fine.
To further reinforce the stone you can also add a layer of tissue paper around the sides and lacquer it, and if you want to go all the way mount it on a base.

Originally Posted by thebigspendur

I've actually never understood it. I always thought the sealant was to protect the stamps.

After-all it's a rock and putting a coat of whatever on will not stop a crack. Most start internally anyway.

Some J-NATS are more prone to cracking, especially Aoto. The sides & base are often coated in urushi over paper. A bit like the concept in fibreglassing.
Might not stop cracks but gives more integrity than without.

I recently sealed one of my stones with 4-5 layers of tissue paper, because I found a crack. I did a coat of polyurethane and then laid the tissue paper on it and made sure it was as flat as I could get. I did this a few more times and then did 4-5 coats of polyurethane as well. From what I understand, this should help protect against further cracking, but we'll see...

I believe that the sealing of the edges was originally done to prevent moisture from entering the end and edge grain of the stones. During cold weather in particular, the absorbed moisture could cause cracking and delaminating. In those days the J Nats did not live the pampered lifestyle (in J ) that we give them today.