Quick Question: Scum along edges of film

[Matt04182]

I've had an issue developing my last two rolls where a kind of white scum draws two parallel lines along the edges of the film. Has anyone seen this? What am I suddenly doing wrong?

 

[Chriscrawfordphoto]

That isn't scum, your film is under-fixed. Throwaway your fixer, mix up a new batch and refix the films (then rewash them). If you don't, the images will degrade.

 

[Matt04182]

Ah, thanks.

 

[jim_jm]

If you're using plastic reels, it's especially important to agitate sufficiently while fixing to ensure it gets to all parts of the film. As you probably know, you can test your fixer by immersing a snip of exposed film leader. Watch how long it takes the film to clear and double that time to get your minimum fixing time for film. Personally, if it takes more than 5-6 minutes for my film to clear, I'll mix up a fresh batch of fixer.

 

[Matt04182]

I usually mix a bottle of fixer once every couple of months -- probably well before I need to -- but I'd lost track of how long it'd been this time around. Thanks for the advice.