Sealing/lacquering stones (synthetic and natural)

[msum]

Hi,

I know there are many threads about this, but I have a bunch of questions about sealing stones which I don’t think are completely answered elsewhere. In no particular order...

- Who here seals splash and go synthetics? I know some do.

- Is there a problem with using polyurethane, other than being untraditional? I have seen fellow Aussies suggest Bondall, which is polyurethane, if I understand correctly.

- Where are people getting cashew lacquer from, these days?

- How bad does cashew lacquer smell (e.g. compared to other alternatives)? When it is described as semi synthetic, what parts of it are synthetic?

- How difficult is Urushi lacquer to work with? I think I can avoid toxicity/allergy problems by using appropriate personal protective equipment. But I worry about having the right conditions for curing. I have seen urushi sold in tubes on more than one website, but not sure how far a tube goes and not sure how to tell whether the urushi is good quality.

- Are there any food safety implications for sealing stones with any kind of lacquer?

- What products do people use to stick stones to bases?

- Does everybody bevel off the edges on sealed stones?

Thanks all!

 

[Nemo]

I seal all of my S&Gs with Bondall Monocell Gold (thanks @Badgertooth for the steer in this direction). It works well. No cracking issues at all. Having said that, I live in a mostly dry climate, so maybe it's the climate rather than the sealing which is protceting my stones... dunno. I don't know whether other urethanes will work as well.

I wash my knives well after sharpening, so hopefully food safety is not an issue.

You can use an epoxy to stick stones to things. What sort of base are you thinking of?. This has the benefit of filling in uneven bits on the base of naturals. Has the disadvantage of being permanent. I have heard of people using contact adhasive on Edgepro stones. Might work on full sized ones.

Not sure what you are getting at with bevelled off edges. Do you mean bevelling the edges of the sharpening surface? Yes, definitely bevel these. Every time you flatten (thus, every time you sharpen).

 

[nutmeg]

urushi is great but takes ages to dry. Sometimes months.. I wouldn‘t use it again!

 

[msum]

Thanks Nemo.

I have oil based Estapol (a Wattyl polyurethane product), so I’d be keen to brush that on. Maybe I can just go ahead and try... Did you go with a spray on Bondall product?

Yes, I assume that after a good washing it’d be okay for food safety, given that dining tables are sometimes finished in polyurethane.

Yes, I meant bevelling or rounding off the corners of the sharpening surface. I assume this would also minimise contamination of the blade with bits of lacquer.

 

[msum]

urushi is great but takes ages to dry. Sometimes months.. I wouldn‘t use it again!

What would you use instead? I’m curious, as I hold your opinion in high regard.

How do you know if Urushi is dry? And is it hard to make a drying box for it?

 

[msum]

I was just thinking I could take a leaf from Banksy’s self-destructing art book and commission a really expensive Urushi artwork on the side of a stone.

 

[XooMG]

Deleted, sorry.

 

[msum]

Thanks.

Mt Fuji? I like it.

 

[zizirex]

I use Spar Varnishes... Doesn't have any problem on my natural stone.

 

[nutmeg]

What would you use instead? I’m curious, as I hold your opinion in high regard.

How do you know if Urushi is dry? And is it hard to make a drying box for it?

I use lacquer for yachts. The one I could find now is very liquid and takes 2-3 days to dry completely, and I need to put several layers.
One stone broke last month so I'm careful with advices lol. But one stone from 500 is not that bad..

I don't know for urushi.. I read here and there that it needs high air humidity in order to dry.
The climate here doesn't allow this.
Some pieces took one month to dry, others 2-3 months..
I noticed Urushi goes deep in the stone so if you don't paint carefully you may need to flatten the stone on few millimeters in order get it clean again.

 

[msum]

The marine varnishes/lacquers seem to be popular! Now we need to debate which brand/model is the be all and end all.

Yes, I have heard that certain humidity conditions are needed. Not sure I’m keen to make a box specifically for drying urushi in, though. I’m leaning towards a simple urethane!

Here is a thread on Fountain Pen Network that I thought was quite useful, though:

http://www.fountainpennetwork.com/forum/topic/116757-urushi-basics/

 

[domrun]

urushi is great but takes ages to dry. Sometimes months.. I wouldn‘t use it again!

25-30 degree Celsius
75-85 % humidity
It will not take more than 24 to 48 hours to dry but you have to apply it in very thin layers.
Two layers are enough 
Humidity is more important than temperature but of course it is better to have a small local ad hoc.
I do this in summer in a shed at the bottom of the garden cause it stinks for a few days but cool results

 

[kerotan]

25-30 degree Celsius
75-85 % humidity
It will not take more than 24 to 48 hours to dry but you have to apply it in very thin layers.
Two layers are enough 
Humidity is more important than temperature but of course it is better to have a small local ad hoc.
I do this in summer in a shed at the bottom of the garden cause it stinks for a few days but cool results
View attachment 65461View attachment 65462

Looks good. What kind of urushi do you use? I tried looking at different websites and they list different kinds of it and I don't mean just the color. Also, do you thin the urushi itself? If so, what do you use?

 

[domrun]

Both have brownish color.
Pure : not filtered
Clear : Already filtered
For stones lacqering, it’s not gonna make a big difference between « pure » and « clear » urushi but there’s some small impurities in « pure » urushi that you need to remove if you want a very fine finish whithout inclusions on a wooden bowl by example.
The stone above is « pure » urushi lacquered.

http://www.namikawa-ltd.com/phone/product/104

 

[kerotan]

Both have brownish color.
Pure : not filtered
Clear : Already filtered
For stones lacqering, it’s not gonna make a big difference between « pure » and « clear » urushi but there’s some small impurities in « pure » urushi that you need to remove if you want a very fine finish whithout inclusions on a wooden bowl by example.
The stone above is « pure » urushi lacquered.

http://www.namikawa-ltd.com/phone/product/104

Perfect. Thank you.

 

[Nemo]

Thanks Nemo.

... Maybe I can just go ahead and try... Did you go with a spray on Bondall product?

Yes, I used the spray.

Make sure you tape up the sharpening surface (I used masking tape).

 

[msum]

25-30 degree Celsius
75-85 % humidity
It will not take more than 24 to 48 hours to dry but you have to apply it in very thin layers.
Two layers are enough 
Humidity is more important than temperature but of course it is better to have a small local ad hoc.
I do this in summer in a shed at the bottom of the garden cause it stinks for a few days but cool results

Thanks!

As asked before do you thin the urushi? Do you filter your “pure” urushi before application?

What kind of applicator brush do you use?

Do you recommend a particular way to get humidity up to 75%?

How bad does it smell? And how does that compare to cashew lacquer?

Any personal protective equipment recommendations? Just gloves and eyewear? Longsleeve shirt?

Sorry about all the questions.

 

[domrun]

No need to thin.
You can use directly out of the tube with a flat brush.
I immerse 3 towels in hot water and I lay them in the small room (1.5 m2) where I store stones.
Never used cashew lacquer so I can’t compare.
Once dry, the smell disappears in a few days.
Bearable but unpleasant, to do outside the house if possible.

 

[msum]

No need to thin.
You can use directly out of the tube with a flat brush.
I immerse 3 towels in hot water and I lay them in the small room (1.5 m2) where I store stones.
Never used cashew lacquer so I can’t compare.
Once dry, the smell disappears in a few days.
Bearable but unpleasant, to do outside the house if possible.

Thanks! This is great information.

Do you measure the humidity with a hygrometer, just to check?

Do you put the stone on top of the hot, wet towels, or are the towels off to the side?

Do you wear gloves when handling the urushi?

 

[domrun]

Thanks! This is great information.

Do you measure the humidity with a hygrometer, just to check?

Yes I do

Do you put the stone on top of the hot, wet towels, or are the towels off to the side?

Towels off to the side [/QUOTE]

Do you wear gloves when handling the urushi?

Yes gloves, glasses and t-shirt with long sleeves [/QUOTE]

 

[msum]

Thanks again!

Do you squeeze the lacquer from the tube onto the brush? Or do you squeeze the lacquer into a little dish/tray and then dip the brush in it?

How do you clean the brush in between uses? Or do you dispose of the brush after each coating?

 

[msum]

How many stones can you do with one 90g tube of urushi from Namikawa?

 

[Forty Ounce]

Thanks! This is great information.

Do you measure the humidity with a hygrometer, just to check?

Do you put the stone on top of the hot, wet towels, or are the towels off to the side?

Do you wear gloves when handling the urushi?

Just thought I'd add something in...
Urushi has urushiol, which is the bad stuff in poison oak. Take this from someone who is horribly allergic.. ACETONE is a lifesaver. If you get it on your skin, use acetone immediately and it should remove the oil and prevent the reaction.

 

[domrun]

Thanks again!

Do you squeeze the lacquer from the tube onto the brush? Or do you squeeze the lacquer into a little dish/tray and then dip the brush in it?

How do you clean the brush in between uses? Or do you dispose of the brush after each coating?

I put a small amount in a glass cup and dip the brush in it
I use very cheap brush for single use

How many stones can you do with one 90g tube of urushi from Namikawa?

One 90g tube for 3-4 stones (200x75x35)
2 applications in very thin layers on each
I read that some only put one

 

[msum]

Thanks everyone.

I’m thinking of giving this urushi caper a go...

I will try to be as careful as possible, since I do experience dermatitis. I too have heard that acetone can be useful for cleanup.

 

[msum]

I received some advice from the owner/proprietor/maker of Manu Propria pens that seshime lacquer has a higher water content than some other forms of lacquer and can therefore be cured in an oven at 130 degrees Celsius.

Can both synthetic and natural stones withstand such temperature? I feel natural stones should, but not sure about the binders and other things in synthetics. I assume it would be bad to put a soaking wet stone in the oven.

 

[M1k3]

I'd worry if the synthetic stone has a resin binder. And being wet.

 

[msum]

I’ve had it confirmed that putting the synthetic stones I own into a 130 degree Celsius oven isn’t advisable.

I am curious as to how badly it would all go, though.

I have also discovered that urushi lacquer is traditionally put into a glass palette, but that plastic can be used instead.

Regard a “muro” in which to cure the urushi, others have suggested to me that wet towels in a lidded contained should be fine and that I don’t need to measure the humidity really accurately.

I’m pretty set on trying out the urushi, so I’ll hopefully be back to update everyone.