Have you ever glued your fingers together?

Old photos (plus 25) years seem stuck together: a solution?

The usual coating of photo paper consists of (hardened) gelatin along with many other chemicals. Unless it has an additional protective coating as described on this Wikipedia image The gelatine is directly exposed to the environment. If you've ever used gelatin in baking or cooking, it gets a little sticky when wet and dissolves completely with enough water and time.

This often happens with photos that get some moisture: the gelatin begins to dissolve slightly and sticks to a surface a little. The behavior is a bit like that of wine gum: if it's not too wet and you act quickly, you can take most of the things that stick to it without causing much damage. Just give it a try: wash your hands, dry them badly so they're damp but not dripping wet, and touch an old photo that you no longer need. Firmly press your fingers on it and remove it. Often times, the photo will already be stuck to your finger, but you can usually easily peel it off. If you look closely at the photo, you can see your fingerprint in the gelatin structure of the photo, but the colors are still intact. When you have a stack of photos that have been in a box for a few years, you often get the same slight stickiness when you browse them. This is the start of a bad effect and a good reason not to save it that way.

Most likely this happened to your photos as well, but instead of pressing firmly, it was time and humidity that made them stick together tighter.

How can this situation (in the truest sense of the word?) Be resolved? If you were so curious as to put some wine gum in the freezer, you will find that they get very hard and break easily at a low temperature. As D. Lambert pointed out, you can try this with the photos too, and the same thing will happen: you will break the gelatin layer. Depending on where it breaks, more or less of the color-bearing material is torn off. Usually the weakest point is only on the surface of the gelatin layer. So if they haven't been together with some pressure, very damp and too long, you should be in luck with this method. Just make sure you don't add more moisture to photos as you freeze them (for example, put in a sealed plastic bag with a bag of silica gel).

Whatever you do, don't heat it (e.g. you might think you can get rid of the humidity this way; in fact, the remaining humidity helps with the freezing method)! Gelatin dissolves completely when cooked at 50 ° C and begins to degenerate chemically at 80 ° C. However, prolonged exposure to anything above 50 ° C is still not a good idea.

For the really bad decals, you might want to help the tear-open process with a thin razor blade. Be gentle Bend the paper a little and wait, the gelatin may take a moment to crack, but if you tear it apart there is a higher chance it won't break on the surface.


Addendum to answering the question of whether "getting them wet again" is a good idea.

From experience, I wouldn't recommend it, at least not the way you make it sound ("wet them up a little bit again" sounds like you want to sprinkle water on them or something).

Ideally, you want to rewet exactly the parts of the surface that will stick most firmly to the next sheet of paper. Unfortunately, for this reason, these are the hardest to reach. Unless you have access to a humidor (or similar environment) to keep the humidity up in a very controlled way over an extended period of time, adding humidity is likely to cause even more damage before it reaches the points where we put it want to have early enough.

In particular, if you are not putting tension on the photos while adding moisture, you are also adding moisture to parts that are not yet adhering and making them sticky and possibly even more sticking to those parts.

If you are able to use the right amount of force and add moisture to that one side of an album in the right way, you may get better results than the freezing method. Especially if the material adhering to the photos is quite porous and too much is already embedded in the gelatin layer. However, all of this leaves much more room for error.

Especially in your case (if I understood you correctly, you glued the two colored areas of the photos together) the risk of a stronger material mixture due to the additional moisture of the gelatin seems to be quite high compared to breaking the gelatin with the hopefully rather weak points .

But just like in archeology (and somehow we seem to be approaching this subject in some way here) without an expert inspection (and I'm by no means one for this type of recovery, my photo recovery expertise is digital based) there is an unlikely one outstanding clear way to achieve this. Even the experts may want to try both methods on a small sample and see how it turns out.

Joachim

Wow that's great, thanks! Somebody told me it might also be a good idea to wet the photos a little bit again. They should come off too and then I could let them air dry well. With your explanation, that makes a lot of sense: The gelatin should partially dissolve again and loosen the adhesion to the other photos. What do you think of this method? However, the freezing method seems a lot safer!

PlasmaHH

@ Joachim: See response update, comment fields are way too small