Film Photography: How long does fixer last?
This is the first of a series of short posts to dispel some of the myths I have come across when teaching myself film photography and more specifically developing black and white film.
Question: How long will fixer keep for once it has been diluted?
(I will use Kodak T-max fixer as an example, diluted 1:4 with water, as this is the fixer I use). I’ve read many different answers to this question but the most common one appears to be dump the developer after each roll of film developed. I develop my own black and white film partly because it is more economical. If I was to dump my fixer after every roll of film home developing would soon prove expensive.
Answer: Longer than you think..
(Based on my own experience)
I made up a diluted batch of 1.5L of diluted T-max fixer 4 months ago and have stored it in a dark cupboard in a clear soft drinks bottle. The bottle is not full to the top so air is in the bottle. Since making the batch of fixer I think I have developed roughly 25 rolls of B&W film (mostly 120 film but the occasional 135 also). I tend to leave the film in the fixer for a longer period than suggested to be safe (20 minutes) but I have not observed any problems so far.
Here is an example from the last roll of film developed:
Yulya, Ukraine with ARAX-CM medium format camera & Kodak T-max 400
*I have read that diluted fixer can be used for as long as six months but so far I have not reached that stage.
Fixer shelf life – Conclusion
Even if you want to play it safe and make up a new batch of fixer every month it will still be much cheaper than making a new batch after each roll.
More film myth breakers coming soon..
How to tell if fixer is still good? Quick test.
A quick test to see if your fixer is still good is to put a piece of undeveloped film into the fixer dilution. Swill the fixer solution around with the piece of film in and the film should go transparent within a few seconds. If the film stays opaque then the fixer needs replacing.