Concentrated Ansco 130 Stock - Shelf-life?

Dear All,

I would like to post here a version of my original question from APUG as it seems no one amongst that group of people has come across my conundrum.

I would like to make a more concentrated stock of Ansco 130 by using only 50% of the water. It is possible to mix it and all chemicals do dissolve, as I have tested this. My question is if such a concentrated stock should have a higher, no different, or shorter shelf-life.

I realise that it is claimed Ansco 130 has a very long stock solution life and the working solution lasts well too. Perhaps any chemists here would know if the concentrated version would be much different in terms of storage. Could concentrating it have any other impact on its performance when diluted again?

Many thanks,
Rafal

PS. I have another question about any experiences (good or bad) of using it replenished over a longer period of time, but I guess I should make a separate thread for it some time later on.

I had conventional-stock-dilution Ansco 130 in full liter plastic Coke bottles for three years. When I diluted them 1:1 for working strength, they were just fine. So I can vouch for three years, but no longer. Full helps, too, by having little oxygen in the bottle.

Thanks Bruce. But would concentrated stock have as good, worse, or better shelf life than what you have experienced with the regular stock?

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Originally Posted by Bruce Barlow

I had conventional-stock-dilution Ansco 130 in full liter plastic Coke bottles for three years. When I diluted them 1:1 for working strength, they were just fine. So I can vouch for three years, but no longer. Full helps, too, by having little oxygen in the bottle.

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I agree with the above. My personal experience has been with 2 year old stock solution.

Quote:

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Originally Posted by Rafal

Thanks Bruce. But would concentrated stock have as good, worse, or better shelf life than what you have experienced with the regular stock?

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I have no experience with more concentrated stock. And if you can't use a gallon of stock a quart at a time in three years...?

Quote:

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Originally Posted by Bruce Barlow

I have no experience with more concentrated stock. And if you can't use a gallon of stock a quart at a time in three years...?

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My immediate issue is that I have materials for 12l of stock and I wish to use less space for its storage. I was advised by PF to mix it as soon as possible and not to store glycin for more than 1-2 months in its unmixed form. I am certain I will go through it in less than 1 year, but I was curious if the life of the more concentrated stock was going to be affected by the fact of it being made with 50% of the suggested water. I am surprised that no one who reads this and APUG forums has tried this before. :)

Many thanks for your kind advice either way.

I am skeptical. Although the glycin might continue to develop effectively, it does
change color over time with oxidation and affects the color of the highlights, if not
the entire print. I have deliberately used aged versus fresh solutions to achieve a
particular look in certain prints. Has anyone else tried this?