How to remove water stains?

[Boris Mirkov]

I recently developed an MF film which has a water stain right on the subjects face! When developing is done I spray the negative with sprayer containing demineralised water and that usually works and leaves no stains. I have no idea how this got to be but I need to remove it outside photoshop because that would be too much altering of the photo. Should I try and wash the negative again?

 

[smieglitz]

If the water stain is on the base side of the film, I have had success using a very soft lens cleaning tissue to wipe it off. I place the negative emulsion side down on a tissue on a flat tabletop and using another dry tissue, firmly wipe the area where the water mark is present. This usually removes the stain although a few passes may be required.

Note that I only do this when the mark is on the base side of the film, not on the emulsion side which is much softer and prone to scratching. I also only use this technique with water marks. If the water mark is on the emulsion side, I rewash, Photo-Flo, and squeegee the film to remove the mark. Oily marks such as fingerprints need to be removed with a film cleaner.

If you are concerned that the procedure will scratch your film, try it on a frame you know will never be printed. Anytime the film surface is touched may lead to damage, but I've had 100% success with this method as long as the stain was on the base side of the film.

 

[darkosaric]

I spray the negative with sprayer containing demineralised water and that usually works and leaves no stains.

Buy 5 liters of demineralised water, after washing - last fill goes with demineralised water, leave it for 3-5 min with some gentle rotation from time to time.

 

[Boris Mirkov]

Thank you guys for the replies.
Unfortunately, it is on the emulsion side. Darko, I was thinking of doing that in the future but it still leaves me the problem of this negative. Will soaking that problematic strip in demineralised water for some time do any good?

 

[Europan]

Water stains or marks are scale. You want to remove that from the gelatin, so soaking alone won’t do the job.

Before taking the film out of the water—you actually rewash it which will swell the gelatin—give it a shot of acid.
The best is formic acid that evaporates without leaving a trace. Citric acid works also but tends to leave a faintly sticky surface. Acetic acid works well but must be more concentrated in your distilled water wash.

 

[Doremus Scudder]

As mentioned above, if your water mark is from hard water (mineral scale) acid is your best friend. Pre-soak the film for a few minutes, then use regular acetic acid stop bath. Soak until the stain is gone. If it takes a long time, you can use a stronger stop bath, but I've had good luck with the standard 2% dilution.

To avoid mineral build up next time, do as darko says, use dimin or distilled water for your final rinse. I use distilled water and a wetting agent and have never had problems after figuring out I needed to do this when living in an area with very hard water.

Best,

Doremus

 

[M Carter]

I've had zero dust and watermark troubles since I adopted this process:

Final rinse: distilled water, photoflo, and a splash 0f 90+% isopropyl (not the 70% grocery store stuff) - this is believed to break up any latent mineral-ness and speed drying (if I'm out of distilled water, I use water from our drinking water filter and continually find this to be fine);

Take a fresh kim-wipe and dry the are where you will clip the film (so no globs of water behind the clip);

Clip, hang, squeegie with fingers dipped in the final rinse (I check my fingers for scratches & rough spots...) ;

Roll a fresh kim wipe into sort of a squeegie and gently wipe the film, top to bottom;

I hang mine in a bathroom where I've just run the shower on hot.

I've never tried acid for treating stains, will remember that one... I keep some 90+ iso in a little cosmetic pump spray bottle and use that and a good, fine paintbrush & loupe for any stuck dust spots discovered when printing.