Tale of very old Rodinal

Alan Johnson · Feb 19, 2023

It is well known that Rodinal [generic term] can deposit crystals, IMO potassium aminophenolate, generally thought to be good crystals that maintain its strength.
Here I discuss a different deposit found in oxidized old Rodinal.

I had some Rodinal 20 years old that worked well and about 5 years ago put some in a 100ml glass bottle with a plastic stopper. Recently I got a blank film from a 1:25 solution of this. There was a non-crystalline deposit in the bottle which I removed for examination [pic].

To all this deposit was added 5g sodium hydroxide and 50ml water. With heating most of it dissolved. A film leader was placed in the cooled solution for 20 min, then fixed. It was clear apart from slight fog. This shows that the deposit from this very old Rodinal was not the active potassium aminophenolate "good crystals" mentioned above. It was very likely some kind of oxide formed from air diffusing in through the plastic stopper over 5 years.
So it seems quite likely that Rodinal only lasts until all the preservative sulfite in it is used up.

koraks · Feb 20, 2023

Alan Johnson said:
It is well known that Rodinal [generic term] can deposit crystals, IMO potassium aminophenolate

Given rodinal's composition I'd expect precipitates to be mostly sulfite.

Alan Johnson · Feb 20, 2023

I used to be indecisive but now I'm not so sure:

Rodinal formula from Wolfen via British post-WWII intelligence

Silverprint has an ad/info in the December 2006 B&W Magazine with a version of Rodinal taken from post WWII military intelligence, modified to use the currently more commonly avaliable sodium salts. That page is available online: http://www.silverprint.co.uk/PDF/Rodinal-4.pdf Lee

www.photrio.com

pentaxuser · Feb 20, 2023

Alan Johnson said:
It was very likely some kind of oxide formed from air diffusing in through the plastic stopper over 5 years.
So it seems quite likely that Rodinal only lasts until all the preservative sulfite in it is used up.

I have 18 year old Rodinal which still works and it has a plastic top that screws onto the neck of the container. So is your stopper in the 100ml glass bottle different from the top on the original bottle? Is the Rodinal from the original container still working OK?

What practical lessons do you draw from your experiment which other Rodinal users should now heed?

It seems that based on your experiment, one of the main lessons to be drawn is that decanting small amounts into other bottles makes Rodinal break down and become useless or is it that the Rodinal bottle's top prevents oxidation but other container tops may not?

I always thought that one of the benefits of Rodinal was that it was largely impervious to the effects of oxidation so that opening the bottle for say only 5ml of Rodinal each time and thus doing this frequently did not carry the same sort of risks that was true of most other developers

Thanks

pentaxuser

Cholentpot · Feb 20, 2023

My 9 year old bottle of Rodinal died recently. There's not much left but enough for a few dozen more rolls. It seems the newer stuff doesn't last forever. 9 years is a long while though. Not complaining.

Roger Cole · Feb 20, 2023

The convenience and long life are so appealing I really wish I could get results I liked from Rodinal. But I've tried several times over the years, going back to the early 1980s and I just can't. Maybe I should give it yet another go.

A bit off topic, I realize.

Cholentpot · Feb 20, 2023

Roger Cole said:
The convenience and long life are so appealing I really wish I could get results I liked from Rodinal. But I've tried several times over the years, going back to the early 1980s and I just can't. Maybe I should give it yet another go.

A bit off topic, I realize.

Depends on the film. I've been primarily using it on Xray film recently. It keeps the contrast low enough.

Alan Johnson · Feb 20, 2023

pentaxuser said:
I have 18 year old Rodinal which still works and it has a plastic top that screws onto the neck of the container. So is your stopper in the 100ml glass bottle different from the top on the original bottle? Is the Rodinal from the original container still working OK?

What practical lessons do you draw from your experiment which other Rodinal users should now heed?

It seems that based on your experiment, one of the main lessons to be drawn is that decanting small amounts into other bottles makes Rodinal break down and become useless or is it that the Rodinal bottle's top prevents oxidation but other container tops may not?

I always thought that one of the benefits of Rodinal was that it was largely impervious to the effects of oxidation so that opening the bottle for say only 5ml of Rodinal each time and thus doing this frequently did not carry the same sort of risks that was true of most other developers

Thanks

pentaxuser

Well, mine was 20 years old before I started this experiment:

Plastic bottles that stop air ingress

I recently bought the illustrated bottle of 20+ years old Rodinal. I get the age from it coming with an instruction sheet listing times for Panatomic-X and Ilford PanF (not the Plus version). The contents were measured as 500ml, equal to that specified on the container, so it was probably...

www.photrio.com

So the main practical lesson is don't worry about it in the case of Rodinal.
This is just a tale of why it does not last for ever.

pentaxuser · Feb 20, 2023

Alan Johnson said:
Well, mine was 20 years old before I started this experiment:

Plastic bottles that stop air ingress

I recently bought the illustrated bottle of 20+ years old Rodinal. I get the age from it coming with an instruction sheet listing times for Panatomic-X and Ilford PanF (not the Plus version). The contents were measured as 500ml, equal to that specified on the container, so it was probably...

www.photrio.com

So the main practical lesson is don't worry about it in the case of Rodinal.
This is just a tale of why it does not last for ever.

Ah, OK. I had anyway made an assumption that as good as its longevity is that no developer lasts forever. It was the decanting into a 100ml bottle and the reference that it was this that had gone bad due to oxidization that made me wonder if there was something about the Rodinal container and its top that per se has stopped oxidization which the plastic stopper had been able to. As I said and as you have experience of, continually taking as little as 5-10 ml out each time over 20 years allows a lot of air in quite frequently with no ill effects

Thanks

pentaxuser

retina_restoration · Feb 20, 2023

Roger Cole said:
The convenience and long life are so appealing I really wish I could get results I liked from Rodinal. But I've tried several times over the years, going back to the early 1980s and I just can't. Maybe I should give it yet another go.

A bit off topic, I realize.

I stopped using Rodinal years ago once I realized how much shadow information I was losing when using Rodinal. If you want a liquid developer with excellent shelf life (and better performance) take a look at FA-1027 from Photographers Formulary.

IMetodiev · Feb 23, 2023

Now I've gotta go and check my stash!

P C Headland · Feb 25, 2023

Roger Cole said:
The convenience and long life are so appealing I really wish I could get results I liked from Rodinal. But I've tried several times over the years, going back to the early 1980s and I just can't. Maybe I should give it yet another go.

A bit off topic, I realize.

Maybe try some some PC-TEA or 510-Pyro. Both have great shelf life - I've got partially used bottles that are over 10 years old.

Tale of very old Rodinal

Alan Johnson

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koraks

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Alan Johnson

Rodinal formula from Wolfen via British post-WWII intelligence

pentaxuser

Cholentpot

Roger Cole

Cholentpot

Alan Johnson

Plastic bottles that stop air ingress

pentaxuser

Plastic bottles that stop air ingress

retina_restoration

IMetodiev

P C Headland

Tale of very old Rodinal

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Moderator

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