How long after development can negatives sit around for until it's too late to refix? I've gone back and refixed negatives a week or two after they were developed and I heard you can do it up to a couple months after the fact. I have some film that was developed about 8 months ago that were poorly fixed (ie: a bit of yellowy tint). Too late? These were done before I understood the importance of proper fixing.
Give it a go and you'll find out. Fixing, even at this late stage will at least get rid of or reduce any uneven stains across the emulsion. Damage done is usually damage done, but I've refixed some of my grandfathers negs from 25+ years ago and seen a massive improvement on the discolouring they had suffered.
Just agitate them in a tray of fixer for a few minutes, wash them then hang em' up.
I refixed some negs that had a purple cast to them and it got rid of that. apparently its not a problem really but i don't trust my schools fixer sometimes. Im starting to make my own now. I would say it cant hurt much just so long as you are careful and wash them again correctly. I just put the strips in open trays of fixer.