J-Nat Club

[Andrey V]

I got the shellac, already in a ready-to-use solution. Also a bottle of overprized isopropylalcohol dubbed 'shellac solvent'. That's how you sell basic stuff for a nice profit.

So, now how to go about it. I want to remove the old laquer from the stone and put new laquer on it. I own three Atoma diamond plates, 140, 400 and 600 grit as well as different grit sand paper. The way i guess it could work is i flatten the sides of the stone with the 140 Atoma which will remove the laquer as well. If there is some laquer left in dents, i can use the sandpaper. Then i'd wash the stone with clear water (to wash out the lose particles which will have accumulated in the little (Suita) holes. Then let it dry and apply a first thin coat of laquer. Then let this dry and coat again.

Is this about right so far and how many thin coats would you suggest? Is there something like a howto already posted somewhere?

Cheers!

Great! So you don't know for now which type of lacquer has your stone, right? I would say- try to use your isopropyl to see if it can dissolve your existing lacquer- just on one side. If not- then you'll have to switch to " mechanical" rather then to " chemical" process. ( not to use " harder" solvent's stuff and just to scratch it off)
I don't see any need to use the sand paper to remove all the particles from everywhere- these are the sides, the coating will be needed to protect the stone from the water, and to " glue"/ reinforce it, preventing developing of new and existing cracks. So it's definitely not a Paganini violin, though the nice finish is welcome .
So all the best for you and show us your result!

[TaJ]

It's most likely shellac. I should have thought about trying ro remove it with the alcohol, good tip! Now, this might be a dumb question, but would i use the diamond plate with water or dry?

[icanhaschzbrgr]

It's most likely shellac. I should have thought about trying ro remove it with the alcohol, good tip! Now, this might be a dumb question, but would i use the diamond plate with water or dry?

From my limited experience with one coarse diamond plate it works well with or without water. Water could help flush away removed material but that's the only difference I noticed.

Out of pure interest: why would you want to remove old lacquer from stone? As Andrey said: stone is not a Paganini violin, why don't just cover it with shellac as is, without using abrasive materials. It would save you some time at least and would give your stone just the same protection from water as if you first remove old lacquer.

[Andrey V]

From my limited experience with one coarse diamond plate it works well with or without water. Water could help flush away removed material but that's the only difference I noticed.

Out of pure interest: why would you want to remove old lacquer from stone? As Andrey said: stone is not a Paganini violin, why don't just cover it with shellac as is, without using abrasive materials. It would save you some time at least and would give your stone just the same protection from water as if you first remove old lacquer.

Agree!!! Some other idea to use: just to scratch it with the sandpaper for better contact and cover it with shellack!
I do it with some old stones ( all my good old-stock stones come already lacquered, but often just with one simple coat).
Additional idea to clean the surface ( maybe you are much more accurate then me, i find always some lacquer dots on the stone surface)- i use the stuff from my daughter's nail polishing arsenal - the liquid thinner for the nail lacquer ( no aceton, no other stuff, mostly alcohol pure )- it works just great! I cleaned up right now all the stones i have lately lacquered easily! But not the nail lacquer remover!!!

[Andrey V]

It's most likely shellac. I should have thought about trying ro remove it with the alcohol, good tip! Now, this might be a dumb question, but would i use the diamond plate with water or dry?

One more question: have you already thought how to clean the diamond plate after? If the base of the previous lacquer is gummy/ pitchy, that will not be that easy, i have some experience . Of course, it can be done, but i still advise just to think maybe to scratch the previous lacquer with some sandpaper for better contact and to coat it with the shellack. Of course, the choice is yours, we just exchange here some opinions!
And: even on my last picture there are 2 stones which had so e previous lacquer on! Coated in same way as described above.

[TaJ]

Thank you for all your tips.

I tried to remove some laquer with the isopropylalcohol, did not work. Either it will take a long time to dissolve the laquer, or it was no shellac and not alcohol-based. So, back to the diamond plate idea.

I wanted to remove the old laquer because it was not pretty, did not cover everything anymore and was flaking off in some places. Just covering it with new laquer would not have made it nicer, also, because of the flaking, it would not have adhered to the stone in these places.

Because today was a nice day, i went to action outside. I chose to go with the Atoma plates and water. My goal was to remove the laquer from all four sides and mostly from the bottom and doing that, flatten the sides and smoothening them almost as much as the top.

So i used the 140 grit plate and ground away the laquer at all four sides. The laquer did not gum up the plates (i was wondering if it would as well). Since the stone was very nicely and evenly shaped to begin with, it went quite good. Only one of the long sides was a bit uneven, so it took longer. After that ground away the scratches with the Atoma 400 and then with the Atoma 600. This being done i beveled the edges a bit. Then there was the bottom. Since that is more uneven i did not want to grind all of that off (my first thought was to make it a second working plane, but i scrapped that). So, i took a new kitchen sponge with a very coarse scrubbing side with which i scrubbed off (with water again) almost all of the laquer on the bottom.

The sides showed scratches from the diamond plates still, so i used my JNS Red Atoma and JNS 6000 to grind them off and make the sides smooth. I know, synthetic and natural stone does not mix well, but i only used it on the sides which will not be used to sharpen anyway. After that i cleaned the stone very well and let it dry for a while. Then, i used a new brush and isopropylalcohol to clean the stone again (remove grease from my hands).

So, that is where i am now, after quite some hours of hard grinding. It looks very good, about how i wanted it to be

I'll try and post some pictures soon.

[TaJ]

Here are the pictures. They don't really show the smoothness of the sides though. The forum software resized the pictures to be really small.

The difference in colour between the before and after pics is because the first were taken in sunlight and the latter with artificial light.

Before:


After:

[Asteger]

Quel changement!

Looks like you removed those Danish swarf stains on the sides, didn't you? Well done. Also, looks like you Atoma-ised the bottom. Very nice.

That one close-up photo really shows the su holes in this one.

[TaJ]

Yep, these ancient stains, which looked like they were even older, like from a Japanese owner some decades ago, are gone. The bottom just looks this way, i just scrubbed it with a harsh scrubbing sponge, no Atoma. And yes, the holes are clearly visible.

The stone is much nicer in person, these tiny pictures cant show that. The different colours with the different coloured renge and inclusions look a bit like pictures of the universe with some nebula and stars shining through. The longer you look the nicer it becomes. You begin to think it's three dimensional.

One of the next days i'll try to laquer it.

[Asteger]

Yep, these ancient stains, which looked like they were even older, like from a Japanese owner some decades ago, are gone. The bottom just looks this way, i just scrubbed it with a harsh scrubbing sponge, no Atoma. And yes, the holes are clearly visible.

The stone is much nicer in person, these tiny pictures cant show that. The different colours with the different coloured renge and inclusions look a bit like pictures of the universe with some nebula and stars shining through. The longer you look the nicer it becomes. You begin to think it's three dimensional.

Whoa, you're getting quite poetic there, Thomas. The universe seen through a single stone.

About the stains being new or old from before, the stone came stamped and so 'new'. However, of course it can happen that a stone maybe be 'old' and is re-stamped by a wholesaler, so you never know. In the end, it's about how it performs and how you like it. Glad you're happy.

Exactly what kind of harsh brush did you use to scrub? Was it metallic and did it remove the old shellac?