I broke open a bottle to try last year, but never used it much since then.... until today when I thought I'd try it with some Acros 100. And the liquid had turned dark brown, like aged Rodinal - I think I opened it 12 months ago. The blurb on the bottle said to discard the developer once it turns dark yellow (or darker). But has anyone tried using it in this state? I'd hate to throw away a nearly-full bottle unless I know for certain that it is useless.
It's dead. Don't use it. It is my favorite developer, but it doesn't last much longer than 2 months after opening the bottle. Unlike rodinal, the brown color is a flashing 'danger' sign.
I asked the same question a couple of months ago, and for the only time ever for me on APUG, got zero replies. Just a couple of weeks ago, I opened an old bottle and the liquid was more black than dark brown so I avoided it like the plague. But I have used it successfully when it was very dark yellow.
Is anyone dividing up the bottle into smaller glass bottles with no air in? I wonder if this would help. I do not have experience of FX-39 but I do this Paterson Aculux and have extended the life of the opened developer from 3 months to 8 months this way. I put it in 30ml one-shot bottles.
I would be interested to know if this method has been tried by anyone with FX-39 because the short life of this developer is a real limitation for those of us who do not shoot large quantities of film.
Also, I wonder what it is in FX-39 that makes it go off so quickly. I know we do not have the formula but FX-37 is in the public domain and this is quite similar according to G Crawley.
It'd like to know where to get hold of small 30ml bottles... sounds like a good plan.
My bottle that I opened 12 months ago has turned rust-brown and I have to throw it away. The fresh bottle was sealed and was still quite clear. I quite like its characteristics with Fuji Acros and would like to use more of it, if only it didn't degrade quite so quickly!
I once put some fresh FX-39 in a full brown glass bottle with a plastic cap and left it for over a year.When I returned it had gone slightly pink but still developed film OK.
Apart from keeping FX-39 in progressively smaller bottles,using Tetenal Protectan spray should help.If this is not available IIRC I saw a post suggesting the use of so called canned air.Mine is labelled "extremely flammable....contains petroleum gas" I would expect it to be inert to developer but have not tried it.
OK, maybe it went the way of my brain. I was trying to say that when I hear about keeping air out of bottles, I wonder how much oxygen that air in a bottle can hold. I have a feeling the real problem is that air that dissolves in the solution while pouring. The best advice then would seem to be the separate bottle scheme where the pouring only happens once into the little bottle and once out of it. I guess any fish would tell us that aerating the liquid is the thing that keeps him alive and kills developers.
I'm going to get those Winchester bottles from Retrophotographic, thanks a lot for the heads-up!
I think I've got some of that Tetenal spray somewhere... bought an enlarger from a guy who gave me a bunch of stuff from his darkroom that I never used.
A note about feeding the fishes.
From the solubility of oxygen,500ml developer contains 4.9mg oxygen.
From the g-molecular wt=22.4 L,500ml air contains 143mg oxygen.
Excuse any error in this calculation,a time since chem lab days.
Nearly all the oxygen comes from the air.