Need help troubleshooting/salvaging a stained negative

henpe · Oct 5, 2021

I need help troubleshooting/salvaging a stained negative.

In the attached negative scan, you should be able to see some brownish/yellowish stains. In the scan, color saturation has been boosted for clarity reasons. The hue is quite true to how the negative looks like.

The stains appear to be on the *base side* of the negative, *not* on the emulsion side.
I used a SP-445 tank to process the negative.
If I recall correctly, the current sheet was processed in a batch in which two sheet somehow stuck to the one sitting on the other side of the film holder (see attached image, the holder takes one sheet on each side with emulsion facing outwards); back-to-back and with the film holder sandwiched in between. After processing, I gently had to separate the sheets in order to unload them from the holder. This of course should explain the regular geometry of the stains. However, I do not recall noticing any marks/stains immediately after the processing and while hanging the negs to dry. The other sheet show similar stains.

My guess is that the sheets have been partly stuck together, back-to-back, during the whole processing (can’t explain why/how this can happen) and that the stains are due improper flow/washout of chemicals, leaving behind either:

oxidized developer ?
fixer remains ?
any other explanation that I have not thought about?

The question becomes, how do I salvage the negative? How to clean of chemical residues like old developer and/or fixer? Remember the stains are on the back of the negatives. Should I simply try to refix the negative, will that remove old fix residues? Can I perhaps clean with a swab soaked in H2O2? Any other alternatives? I really want to try salvaging this neg.

/Henrik

Don_ih · Oct 5, 2021

I think I would try putting the negative in a tray of water with photoflo and rubbing that area with my thumb.

I cleaned a pretty old negative that was truly very dirty using dish soap. It didn't seem to harm the emulsion. I didn't really have anything to lose, though.

Kodak used to sell bottles of film cleaner - the nastiest stuff imaginable. I tried to use some a few years ago. One drop of it and I had to evacuate my darkroom for hours. I'd advise not looking for that.

Kino · Oct 5, 2021

Simply re-process the film at your previous time/temp. Go through the entire develop, stop, fix and wash/dry cycle. If that doesn't remove the stain, it probably won't come out.

Brown stains can be minimized by printing with blue light if it really bothers you and it isn't removed by rewashing the film; the above process...

The above mentioned Kodak Film Cleaner is not a good choice for chemical stains. It is designed to remove grease, finger prints and other residue from film and should be used in a well ventilated area.

ic-racer · Oct 5, 2021

I'd just burn those areas if the are too light in the print.

pentaxuser · Oct 5, 2021

Kino said:
Simply re-process the film at your previous time/temp. Go through the entire develop, stop, fix and wash/dry cycle. If that doesn't remove the stain, it probably won't com out.

Brown stains can be minimized by printing with blue light if it really bothers you.

Can you say what the complete process does compared to just photo-flo, neg cleaner etc? How does a repeat affect the already developed., fixed and washed film. I cannot get my head around what re-development and re-fixing does.

Thanks

pentaxuser

Kino · Oct 5, 2021

pentaxuser said:
Can you say what the complete process does compared to just photo-flo, neg cleaner etc? How does a repeat affect the already developed., fixed and washed film. I cannot get my head around what re-development and re-fixing does.

Thanks

pentaxuser

It allows the emulsion to re-swell to maximum diffusion of chemistry, thus allowing better washing of the emulsion down to the base.

There is a Kodak formula for rewashing negatives, but its much more simple (and probably cost effective) to just simply use your normal developer than compound yet another bottle of chemicals that can go bad before being used...

pentaxuser · Oct 5, 2021

Kino said:
It allows the emulsion to re-swell to maximum diffusion of chemistry, thus allowing better washing of the emulsion down to the base.

So both the re-development and re-fixing stages allows the emulsion to swell in a way that simple re-washing does not? What is it in the developer and fix that swells the emulsion the second time around which simple water does not?

It is an interesting method which I don't think I have seen many mentions or any mention of in past rescue film threads

Just as an aside does the redevelopment and re-fix change the look of the neg i.e. make a difference to its tones or is it simply that both somehow re-swell the emulsion for better washing but have no other effect? If so, does this mean that the developer and fix remain as they were such that they can be used in normal development and fixing as if they had never been used at all?

Thanks

pentaxuser

Kino · Oct 5, 2021

The process shouldn't change any aspect of a fully developed/fixed negative other than allowing by products that shouldn't be in the emulsion to escape.

As for reusing the developer, I wouldn't see it being a problem with a replenished developer, but if you use it one-shot, it would undoubtedly oxidize enough to alter development characteristics, so I wouldn't re-use it to be on the safe side.

A search on "rewashing film" will give you past discussions of the process, but this one has most of the particulars.
https://www.photrio.com/forum/threads/emulsion-softeners.181317/#post-2377447

henpe · Oct 5, 2021

Kino said:
...It allows the emulsion to re-swell...

Remember that the stains are on the back of the negative and not on the emulsion side, so there should be no need to swell the emulsion, right? Also, I guess, the stains should not be due to unexposed silver-halides remaining in the emulsion.
More likely, they can be due to fixer salts remaining on the film base due insufficient flow during processing? Question remains how to remove the deposit?

Kino · Oct 5, 2021

henpe said:
Remember that the stains are on the back of the negative and not on the emulsion side, so there should be no need to swell the emulsion, right? Also, I guess, the stains should not be due to unexposed silver-halides remaining in the emulsion.
More likely, they can be due to fixer salts participating on the film base due insufficient flow during processing? Question remains how to remove the deposit?

And remember that the film won't be touching another surface, trapping the salts onto the base. Try it or don't; not my problem.

henpe · Oct 5, 2021

ic-racer said:
I'd just burn those areas if the are too light in the print.

I don't think I have the skills to burn them in without leaving tell-signs, the stains are too "thin" for that.

henpe · Oct 5, 2021

Kino said:
And remember that the film won't be touching another surface, trapping the salts onto the base. Try it or don't; not my problem.

I did not intend to be provocative with my reply, sorry if that was the case.
I will try to re-process and see if that helps
Regards
Henrik

AgX · Oct 5, 2021

pentaxuser said:
So both the re-development and re-fixing stages allows the emulsion to swell in a way that simple re-washing does not? What is it in the developer and fix that swells the emulsion the second time around which simple water does not?

Gelatin swelling is pH-dependant.

pentaxuser · Oct 5, 2021

Thanks, Kino and all the others for the comprehensive replies. I haven't experienced this kind of a problem yet but it is useful to know about this re-process method and how it works

pentaxuser

MattKing · Oct 5, 2021

The reason that you include the development step is because it prepares the negative properly for the fixer.
Most likely the fixer and post fixer steps are the ones that do the job.
It may be anti-halation material that didn't get properly cleared.

Need help troubleshooting/salvaging a stained negative

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