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Silver Nitrate as a stain


Janel

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This is from Peter Welsh, as we were considering ways of producing a dark monochromatic stain:

 

You might consider Silver Nitrate solution for a mid-dark brown. It is very fast colouring and, is permanent. You will, of course, need to experiment. I think Doug is trying this stain, also. It is caustic in strong solutions and, will turn your fingers a really nice shade of brown. (in fact anything organic).

 

The apple is the darkest shade achieved, the octopus pot, the lightest. Both are holly, from the same piece of timber. The darker shade was achieved with a stronger concentrate. Actual daylight also makes a difference. If you do decide to try this, an overcast day will not produce good results. Leave the treated piece until good daylightis available.The colour change is dramatic!

 

We think it may be possible to 'stop' the colouring, by using one of the photo-processing chemicals. Just haven't gotten around to trials - yet!

 

AgNo3_apple_pw.jpg OctopusPot_pw.jpg

 

What does anyone in the membership know about using silver nitrate? Where does one purchase it?

What safety things do we need to know?

 

(My dad (a doctor) years ago had wood sticks (much like skewers) with a dot of the chemical on the end of it. He would apply it to a spot of something on the skin of a patient for treatment, but I do not know what for.) I remember him showing it to us and how it stained.

 

Masatoshi speaks of using silver nitrate in the book about his work. That is at the studio, so I won't quote anything right now...

 

Janel

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Hello Janel,

 

I read the info on silver nitrate and was wondering if it could be used on a larger scale than netsuke. Is it cost prohibative or too caustic for larger scale use.?

 

I just used the ebonizing technique for wood (vinager & steelwool)? It worked great for a cherry base I just did for a stone piece. From what I've read though, ebonizing only works on woods with tanins(?). I thought it might be good to use in the future as a stain for netsuke projects, but found it absorbed easily and might not be controlable if only certain areas needed staining.

 

(Forgive me, but this is kind of two different questions.)

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Silver nitrate is of course used in photography- but a 1950's chemical dictionary I just looked at says it also had a use with mother of pearl (though it doesn't state what that actual use was :angry: ...- perhaps to turn normal pearls into black pearls by unscrupulous dealers?)

 

The 2006 edition of the Sigma chemical catalog sells Silver nitrate at reagent quality (not the purest) at $60.60 for 25 grams. So it's a wee bit expensive :)

 

Thanks for those photos Peter- The octopus pot is just about the sort of yellow/grey/brown color I've seen on a few netsuke in various books and have wondered about. Of course you experiments were on holly- so I would suspect boxwood would have a slightly more olive-green tinge to it.

 

 

AgNO3 drops used to be placed in infant's eyes at one point to clear up chances of developing gonnorhea...

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Hi Helen- you're right about the ebonizing treatment requiring tannins to work well. The tannins and the iron create a complex on the wood called iron tannate. The same chemistry was used since Roman times to dye leather, and create iron-gall ink- the chief manuscript ink up until about the 1920's. It's something we deal with a lot as paper conservators: http://www.knaw.nl/ecpa/ink/ink.html

 

Boxwood is much lower in tannins than oak for instance, but there's no reason you can't experiment with supplying the necessary chemistry first. Some older recipes for ebonizing wood call for coating the wood first with a solution of logwood extract (you can buy this, and logwood chips from a lot of better-quality artist supply houses.

Check out

http://www.kremer-pigmente.de/englisch/catalog.htm

 

The logwood then acts as a sort of color-changing indicator for whatever is applied afterwards. If your application is followed by the vinegar/iron filings the stain will be black. One source I'm looking at gives a whole list of chemicals and the resulting colors.

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I located another, less expensive source of AgNO3 in N. America- It's called Photographer's Formulary,Inc. www.photoformulary.com

Their 2005 catalog lists 10g @ US$11.50, 30g @ $29.95. It'll be of a less pure grade than the chem catalogs, I suspect, but for our uses I doubt it would matter.

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Could you etch the surface with an acid briefly to open the glossy surface microscopically? Remember to rinse or to neutralize with soda and water if using acetic acid. (I do that, anyway, but don't know if that is proper, any opinions?)

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Just a note about Silver Nitrate

It is not a staining agent.

The minute particles of silver are photo sensitive. They darken but do not adhere to anything. In order to make the coloration "stick" you would have to mix it into some type of adhesive solution, clear shellac, weak glue, etc. then coat the item with the mix.

 

Acetic acid stops the action.

 

Sodioum thiosulfate fixes it permanently.

 

Then it would need a rinse to clear off all the chemical residue.

I would definately experiment on scrap first to see what the resulatant damage might be.

None of these chemicals are inherantly dangerous. I have lived in them for years and so did my parents who were photographers and made everything from raw chemicals.

 

Silver nitrate is the chemical they put in babies eyes to prevent damage from STD's in the old days. At the molecular level silver is a wicked antibacterial agent.

 

Ingestion of silver does no damage. The only great side effect was noted in England years ago as the very rich who always ate with pure silver utensils and oft times on silver plates had problems as the ingested silver migrated and stayed just below the surface of the skin where it stayed, forever. After a short time in the sun, the silver would react and darken giving the one the appearance of of turning a grey blue color. Hence the term English Blueblood.

 

Surface stains on your skin will wear off after a time but I would strongly suggest you play with rubber gloves on.

 

Colloidial silver might be fun to play with. The molecular structure is much smaller than the stock silver nitrate solutions you could make from warehouse chemicals. It is ingestable ( i use it to combat colds and such, as an antibiotic and to kill bad odors. too much of it will eventually turn you blue too so it should work better for staining as it would deposit itself further into the recesses of a particular material.

 

Its easy to make and there are many articles on the net concerning the process.

 

Silver nitrate can be purchased in premixed solutions for application on a variety of materials Ie Glass, wood etc. to make them photo receptive using a negative image in contact. It's all the same process

 

Have fun.

Steve (too many years as CSI!)

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Here's a website that maybe a source of AgNO3:

 

www.silvernitrate.org

 

On this site they were selling 40 grams for about $38.

 

Maybe a you know a chemistry teacher or chemist that could provide you with a small amount.

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  • 2 weeks later...

As was said, a salt is the combination of an acid and a base. The most common example is table salt NaCl. You make table salt by combinint hycrochloric acid (HCl) and sodium hydroxide (NaOH). The reaction goes like this:

 

NaCL + NaOH -> NaCL + HOH (water)

 

A variety of different inorganic acids and bases will form salts in this way. AgNO3 being made from a hydroxide of silver and nitric acid.

 

Ralph

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A variety of different inorganic acids and bases will form salts in this way. AgNO3 being made from a hydroxide of silver and nitric acid.

 

Or you can just dissolve the silver in nitric. Wondered about producing silver chloride (for silvering other metals) from Ag & HCl, but my suspicion is that because the chloride is not water soluble (the nitrate is), its formation would inhibit any further reaction.

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