Salvaging water damaged negatives stuck in paper sleeves
I'm new to this site, and wonder if anyone can help...
Does anyone have any experience of separating negatives from polymer film fronted, paper backed negative sleeves (standard Patterson type)? I have a number of pages of negatives from a folder that got water damaged – I have experimented on a strip by cutting close to the negative with scissors to liberate the strip with attached front and back leaves. After a long soak in very dilute washing up liquid the front foil and paper back could be separated fairly easily, although traces of the paper, or its imprint, remained in the emulsion corresponding to deep shrinkage creases in the paper. A certain amount of very gentle rubbing between finger and thumb reduced the residue/marks, but not all traces could be removed.
Obviously washing up liquid is not the best thing (this was a try out on an uninspiring neg strip) and perhaps soaking in Photo Flo would be preferable, unless someone can recommend something more appropriate - are there any other products or techniques for salvaging negatives damaged in this manner? Lacquers or coatings? Or perhaps methods of copying/scanning (dare I mention anything digital)
Thanks and best regards,
When you do a long soak, be very careful about bacteria in the water eating up gelatin. When this happens, gelatin becomes soft and dissolve into water. Use a silver- and gelatin-safe biocide.
So, the remaining issue is the mechanical imprinting on gelatin only? umm...
Back in the early 1970's when salvaging damaged prints, that had got damp and stuck together, it was necessary to add some formaldehyde to the water used to soak them. This prevented over-softgening of the emulsion and also prevented further damage to areas where emulsion had already broen down.
You only need a few drops of formaldehyde per litre and plenty of wetting agent - a bit stronger than nornal, this also kills any bacteria which as Ryuji points out causes serious damage.
You need patience but it can be done.
I recommend against formaldehyde for a number of reasons.
Formaldehyde is more volatile and less effective than glutaraldehyde. So the latter is better, if you must.
Aldehydes are taken up by the gelatin and the amount of free aldehyde available to kill bacteria may be limited.
So, it is wise to use biocide that is not consumed by reacting with gelatin.
I actually published a paper on this topic in Journal of the Society of Photographic Science and Technology of Japan. Look at June 2010 issue.
One reason for using formaldehyde is that it was the reccommended hardener for emulsions and has good anti bacterial properties. Many of the bacteria may well already be in the surface of the gelatin so the fact it's taken up by the gelatin is beneficial and there should be sufficient excess in the water as well.
Up until quite recently Formaldehyde was used in colour stabilisers, however it went out of use when colour emulsions were given far better hardening during coating.
Gluteraldehyde may well be a better hardener for emulsion manufacture but in practice formaldehyde is more widely available and is extremely effective when conserving and rescuing damaged negatives and prints.
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The reason for formaldehyde in the final bath of color processing is to deactivate the color dye couplers that were not reacted during development process. If left untreated they can cause stain later. For this purpose, the required concentration of formaldehyde is very low. Too low to do anything meaningful about hardening gelatin.
Originally Posted by Ian Grant
Glutaraldehyde is uniformly superior agent than formaldehyde in terms of biocidal effects and gelatin hardening effect.
What’s more important is that, once the gelatin is deteriorated by bacterial action, no hardener can change course. It is too late. So, the hardening action is really not helpful once it happens. That is why I recommend pure biocide like sodium 2-phenylphenol solution, which is readily available (and safe to use with photographic materials).
My experience with water damaged prints with traces of mould etc was that the formaldehyde hardener made a huge difference to the final outcome, with no hardener there was much greater loss of gelatin from damaged areas when the prints were washed, with good hardening this was minimesed. This was important as the images belonged to a Museum.
Originally Posted by Ryuji
I have salvaged water damagednegatives that have stuck to sleeves and there's no way I'd do it without a good soak in water with a hardener simply because it minimises the risks of further damage to the emulsion surface.
Last edited by Ian Grant; 01-14-2012 at 04:23 AM. Click to view previous post history.