I tried to do some searching on cleaning negatives but didn't find exactly what I was looking for in this instance. I've been asked how best to clean some old 35mm negatives that have been peed on by a cat, obviously they weren't well kept. The cat pee is old and dried on the negatives. It doesn't sound like a good prognosis for any parts of the negative emulsion that has dried up cat urine on them but I first thought maybe a slightly warm water soak that might help but idk for sure. What about isopropyl alcohol?
Cat pee negatives
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Boy, this is a new one. I'd just rub them real well with cat litter. It'll certainly take the stain out. As for the smell? I'd probably use a pine scented cat litter.
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Perhaps the feline version of these types of products. These work great for “incidents” on carpet and hard surfaces. Not sure how photographic film will fare, though.
I think this is probably the best advice, and lean heavy on the "mild" part.
Apparently this has happened before…
What about a bicarbonate solution with baking soda, and if that's ok, how mild a solution should it be?
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We have a cat, named Max, that frequently urinates on the carpet. I use the cat version of Nature's Miracle, and also Rocco & Roxie. They are enzymatic cleaners that break down the components in the urine that smell. Cat urine smell is worse than Dog urine smell.
[5-minute interlude of one of our non-carpet-peeing cats (Frankie) walking in, climbing on my lap, and kneading my stomach. Coincidence? I have to see if she's secretly on Photrio.]
The cleaners don't always completely remove the smell from the carpet, but do a respectable job. They clean much better on "hard" surfaces.
You really have to saturate the area, and let it soak for at least 15 minutes - preferably more. For film you'd want to soak, then wash, then use a PhotoFlo-like final rinse. You may have to do it several times.
However, I don't know if the cleaners will damage the negatives, so it may be a risk, as BrianShaw stated.
On the other hand, you can always store them apart from other negatives, so if you can't get rid of the smell, but CAN get rid of the residue, then using a standard cleaner meant for film would probably be fine, starting with distilled-water soaks to get the easy stuff off. You want to preserve them and possibly print/scan. It doesn't matter if you have residual odor as long as you can keep them from degrading further (which is difficult to know).
Whatever you try, a proper negative wash (or several) should follow, along with re-stabilization if they are color.
[5-minute interlude of one of our non-carpet-peeing cats (Frankie) walking in, climbing on my lap, and kneading my stomach. Coincidence? I have to see if she's secretly on Photrio.]
The cleaners don't always completely remove the smell from the carpet, but do a respectable job. They clean much better on "hard" surfaces.
You really have to saturate the area, and let it soak for at least 15 minutes - preferably more. For film you'd want to soak, then wash, then use a PhotoFlo-like final rinse. You may have to do it several times.
However, I don't know if the cleaners will damage the negatives, so it may be a risk, as BrianShaw stated.
On the other hand, you can always store them apart from other negatives, so if you can't get rid of the smell, but CAN get rid of the residue, then using a standard cleaner meant for film would probably be fine, starting with distilled-water soaks to get the easy stuff off. You want to preserve them and possibly print/scan. It doesn't matter if you have residual odor as long as you can keep them from degrading further (which is difficult to know).
Whatever you try, a proper negative wash (or several) should follow, along with re-stabilization if they are color.
I would simply wash in warm water, nothing over 100F. Maybe a couple drops of liquid dish soap. Should be mostly water-soluble. As long as they're not stuck together.
Is this worth the effort?
Is this worth the effort?
The best answer I can give is that it is to the one who reached out to me and asked for my help, so I'll do what I can.
I'd stick to process temp water 20°C
Don't do anything that will soften the gelatin emulsion. I would try to get the strips onto a Paterson, AP, Jobo type reel and wash for 10-15 minutes with gently flowing water 90-95°F. Try to stay with known photo processes. Really hot or acidic/basic should be avoided.
Finish with Photoflo. Even if you don't completely eliminate the odor, most important thing is saving the images.
Finish with Photoflo. Even if you don't completely eliminate the odor, most important thing is saving the images.
Another vote for starting off with a soak followed by a simple water wash with standard agitation in a hand tank, maybe that does the trick.
Wetting agents like ilfotol are basically just soap so you could try a wash with that added to the water too. You can be sure they are safe for use with film and it might also help lift some of the oils.
Wetting agents like ilfotol are basically just soap so you could try a wash with that added to the water too. You can be sure they are safe for use with film and it might also help lift some of the oils.
Exactly.
Start with a soak in water, no hotter than tepid. Prolonged exposure to something aggressive may very well have softened the emulsion. You don't want to risk it floating away off the base in tiny little fragments in a carbonate bath.
Soak for a few minutes initially, then wash, dry; see how it holds up. If it helps and does no harm, repeat to see if you can get it all out.
Remjet remover (soda + sodium sulfite)? Thorough wash and Photo-flo?
I am not sure about isopropyl or ethanol.
I am not sure about isopropyl or ethanol.
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I doubt alcohols would help, except intheir limited capacity as surfactants, as urine is water based and should be water soluble. I'd certainly add photo flo to the water.
A weak bath of acetic acid might be worth a try as it is decent at fighting odours in general household use.
A weak bath of acetic acid might be worth a try as it is decent at fighting odours in general household use.
A small amount of sodium carbonate in water will aid in removing whatever is on the negatives and won't do anything to the negatives themselves. There's no reason to let the negatives soak long enough for the gelatin to soften. The developing process is far more aggressive than wetting dry negatives, agitating a bit, then rinsing them.
It's a strip of plastic with some cat pee on it. Rinse it off. I'm pretty sure cat pee isn't superglue.
It's a strip of plastic with some cat pee on it. Rinse it off. I'm pretty sure cat pee isn't superglue.
The point is that this film was developed long ago; since then, it was subject to pollutants that may have affected the stability of the emulsion. For that reason I would not recommend starting with an alkaline soak. The amount of carbonate does not matter all that much in this regard as pH of even a very dilute carbonate solution easily exceeds 10 (which is already more alkaline than many B&W developers). Moreover, softening of a gelatin layer in an alkaline solution is a very rapid process; within a minute or two, the emulsion will swell/soften noticeably.
In this particular case, I see no reason to risk it, especially not as a first attempt to repair the damage.
And then what will that do? Good luck soaking the emulsion off the film in a few minutes.
But it hardly matters. Water alone will likely get rid of the urine.
Thank you all for your advice.
I failed to mention that these negatives were cut but not put in sleeves, which would've been protective, but had these attached to them for use in a ring binder apparently. Im not sure how old they are versus how old the urine is that's on them. I asked if they came off easily, he removed one.
I'll start with the safest option, a warm water soak and wash and just use a tray.
I failed to mention that these negatives were cut but not put in sleeves, which would've been protective, but had these attached to them for use in a ring binder apparently. Im not sure how old they are versus how old the urine is that's on them. I asked if they came off easily, he removed one.
I'll start with the safest option, a warm water soak and wash and just use a tray.
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The lack of sleeves may have been helpful, in fact. At least, the gelatin hasn't fused and/or ferrotyped against the sleeves. Such damage is often irreversible.
I also see these are B&W negatives, which means they're inherently a lot more resilient than color negatives.
I also see these are B&W negatives, which means they're inherently a lot more resilient than color negatives.
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