[wet plate collodion] Old (8 years old) silver nitrate solution + bottle of undetermined clear liquid

Hi there !

I have two 1 litre glass bottles that are 7-8 years old (from 2015) that I last used for the wet plate collodion process (see attached pictures) :

1. One is labelled AgNO3, so it is clearly a silver nitrate solution. I can see some black dust at the bottom. Regarding this bottle, my question is : Given the price of silver nitrate, instead of throwing it away, can I still sun + filter it and adjust its density so that I can still re-use it ? Or Would you consider it to be too old ?
2. The other one is full of a clear liquid, but it is unlabeled. It is very likely simply some water, but it could be silver nitrate as well (despite there is no black particles in it...). Do you know any very simple test that that I could make to determine whether or not it is silver nitrate ?

Thanks !

PS: Another unrelated question, but still about the silver nitrate bath : I've read that the silver bath must be "iodized" before the first use, that one should cover a plate with collodion and place it in the silver bath for several hours for it to work better with the first plates... Is this correct ? This is something I didn't do 8 years ago iirc...

For #2: Put a drop into a bit of tap water (or salted water to be sure) and if you see white precipitates or haze formed, it may be silver nitrate, if none, then it is definitely not. If it does turn white, leave it in the Sun - it should form black particles if the original liquid was silver nitrate.

:Niranjan.

nmp said:

For #2: Put a drop into a bit of tap water (or salted water to be sure) and if you see white precipitates or haze formed, it may be silver nitrate, if none, then it is definitely not. If it does turn white, leave it in the Sun - it should form black particles if the original liquid was silver nitrate.

:Niranjan.

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Thanks. The test w/ salty water makes sense !

largo said:

can I still sun + filter it and adjust its density so that I can still re-use it ?

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Certainly! Silver nitrate also in solution is very stable. Your bottle shows no signs of deterioration of the solution. It doesn't look like it even needs any sunning. Just check density and replenish if necessary.

largo said:

I've read that the silver bath must be "iodized" before the first use, that one should cover a plate with collodion and place it in the silver bath for several hours for it to work better with the first plates... Is this correct ?

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Apparently this is correct; otherwise your first few plates will be kind of wonky as part of the bromide/iodide salts leach out of it until a balance is reached in the silver bath. The initial plates will likely work, but not exactly like later plates run through the silver bath.

nmp said:

For #2: Put a drop into a bit of tap water (or salted water to be sure) and if you see white precipitates or haze formed, it may be silver nitrate, if none, then it is definitely not. If it does turn white, leave it in the Sun - it should form black particles if the original liquid was silver nitrate.

:Niranjan.

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Thanks once again.

When I opened the unlabelled bottle, a small smell of alcohol came out, which made me think that it was probably not just water...

I then did your test, which was very conclusive: immediate formation of a white precipitate (see attached pictures). It is indeed silver nitrate.

Cool...now please do label it. Or someone might think it's Raki...

:Niranjan.

nmp said:

Raki

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