cleaning damaged slides

This is one for the books. My cat urinated on a number of slides. I've considered everything from dishwashing liquid,to Photo-Flo,to lye soap, but I've held off pending wiser counsel. Any solutions? Please, no pee jokes. I've heard enough.

I've never had that problem, but what I would try if they were my

negatives is to take the least important negative, and try immersing

it in an acetic acid bath. The reason I suggest this is that cat

urine is a very strong base, and the acetic acid should neutralize it.

 

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It might stain the negative, as when you mix an acid and a base, you

get salt and water (if I remember my chemical theory). A thorough

wash and immerion in a wetting agent, such as Kodak Photo-Flo, would

be desirable before drying.

 

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I recall reading in a newspaper column advice for a person who had the

problem of cats spraying on the siding on his house; it was suggested

that he try a 40% solution of acetic acid (2 parts glacial acetic acid

to 3 parts water) to neutralize the odor. The stop bath suggested for

general photographic use is a solution of about 1.3%, which probably

have little or no effect on the cat urine; I would hazard a guess that

a 28% solution would be the best place to start. If it doesn't work,

try a more concentrated solution. Be sure to take all the usual

precautions, such as eye and hand protection when handling acid, and

don't forget to add the acid TO the water, not the other way around!

 

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Let me know how you make out.

I should have read your posting more carefully; you did say SLIDES!

Try my suggestion on your least important SLIDE; I'm not sure what

effect acetic acid of 28% will have on the dyes.

I would guess that most of the minerals and proteins are water soluble

anyway as the cat uses water to wash them out of its body. So maybe

you should try water (maybe with a wetting agent in the last bath)

first.

Donald:

I don't know if using acetic acid will solve your problem or not,

but I do know that you should not use glacial acetic acid (or

anything nearly that concentrated). It is not necessary, and is much

more likely to harm the slides than duilute acetic acid. (I don't

like to tout degrees, but I do have a PhD in Chemistry.) Urine

contains ammonia, other amines, minerals, salts, etc. All of which

are water soluble. The overall pH of cat urine is basic, but is not

characterized as strongly basic. I would suggest soaking a test

slide in a large amount of water (preferrably distilled, can buy in

supermarket); I would also use warm water, since the E6 process is

run at 100.4 degrees. This should bring most if not all the urine

residue into the water solution. Then I would change the water and

resoak in a dilute sloution of acetic acid (as a guess, even more

dilute than stop bath, and probably at room temperature). Let the

slide soak for a few minutes, and then rinse in clean warm water.

 

As an aside...There are many reasons why you don't want to or need a

concentrated acetic acid solution: (1) it is corrosive, and may

destroy the dyes; (2) based on numbers, you don't need it. There is

plenty of acid present in dilute acetic acid to neutralize the amines

in the quantity of urine present; (3) as part of the acid + base =

salt and water reaction, heat is formed as a byproduct. Using a

concentrated acid, will result in a very loacalized generation of

heat (probably right on the film surface), which could be enough to

damage the emulsion. In a dilute solution, the water acts

to "buffer" the heat, and prevent any localized heating.

Good luck and hope this helps.

Arnie

One major problem with all the above advice. The color dyes are

stabilized from fading with a formaldehyde solution, somewhere in the

development process. If you just wash the slides in water (which is

how I would start), the dyes will rapidly fade over time.

 

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You need to re stabilize them. The Kodak process took the

formaldehyde out of the final rinse years ago, the final rinse is

similar to PhotoFlo with an activator for previously introduced less

hazardous formaldehyde compounds early in the process. The other

processes (Jobo/Tetnal, Beseler, Unicolor, etc) still have a

formaldehyde based final rinse/stabilizer step. Some of thoese sell

that step separately from the whole kit. You should use this as the

final step in recovering the slides.

 

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And of course, start by removing them from the mounts. While they are

wet, watch that they don't stick together.

 

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Overall, I would remove them from the mounts, wash them in distilled

water, with several changes of water, then stabilize them, then

remount when dry. If you wash with water, you really don't need an

acetic acid step, but if you want to do that, it probably wouldn't

hurt. I would use 1/2 strength stop bath, and NOT indicator stop

(could add the indicator color to the slides).

I actually have prints that have been urinated on by my cat. Some have partially dried and have white/yellow crusty residue. Others are stuck together. All have a foul odor. Anyone with any help? Even if I clean them, can I get rid of the odor? And will they damage other things in my scrapbook (page, paper, etc?) Thanks! Many of these pictures are irreplaceable.

<p>Hi,<br>

I know this is an old post but I've found a box of old Fujichrome plastic mounted 35mm slides that my cat peed in. <br>

I have no knowledge of chemistry so I'm looking for someone to distill the above information into simple numbered steps that a layman can understand and follow. I live in the UK and so need to buy any products there.<br>

From what I can work out I should do this:<br>

1. Remove slides from the plastic mounts.<br>

2. Soak in warm water with several changes in water.<br>

3. Allow to dry and then soak in a stabilizer.<br>

The 'stabilizer' is the main issue for me. I'm assuming it will protect the slides and prevent rapid fading. Also, I need to be able to buy a suitable and easy-to-use product as I have no chemistry knowledge.<br>

4. Allow to dry and remount.</p>

<p>Kind regards,<br>

John</p>