How To Uncurl Old Negative Film

[Deltapeter]

I have a box of Panoramic Negatives from the early 1900's. Most of them are VERY tightly curled. I was able to open some of them and place them between two sheets of glass I had cut to size to place on my scanner. Some are so brittle and tightly curled that they rip when I try to open them. I am looking around web sites for tips on how to solve my dilemma. For a thought, maybe holding one over a steam kettle or something like that. I don't want to take a chance on damage. Anyone out there with any suggestions?
Thanks.

 

[djacobox372]

Anything you do yourself will be taking a chance... if they matter that much to you send them to a restorer.

In my experienced, badly curled film needs to be soaked and dried. Once dried they'll likely be still curled, just not as bad and not as brittle. Place between a couple heavy books for a few days and then scan.

 

[Dwig]

I have a box of Panoramic Negatives from the early 1900's. Most of them are VERY tightly curled. I was able to open some of them and place them between two sheets of glass I had cut to size to place on my scanner. Some are so brittle and tightly curled that they rip when I try to open them. I am looking around web sites for tips on how to solve my dilemma. For a thought, maybe holding one over a steam kettle or something like that. I don't want to take a chance on damage. Anyone out there with any suggestions?
Thanks.

Roll films from that era are almost always on a cellulose nitrate (aka nitrate) film base. This material is extremely flammable. When it begins to deteriorate (becoming brittle is one symptom) the likelihood of it spontaneously ignite increase and can occur at temperatures as low as 100F (38C). Do not heat unknown film.

Also, once it begins deterioration the emulsion is likely to life off is moistened. Even if the negs are on the early "acetate" film bases (cellulose diacetate, ...), which began to appear around 1923, the emulsion will lift off easily if the base has begun to deteriorate.

Nitrate base films can usually be identified by scraping off a small portion of the emulsion. If the base that is revealed is yellowish or brownish it is almost certainly nitrate base film. The various acetate bases are clear or neutral grey when the emulsion is removed. The early acetate base, cellulose diacetate, gives off a characteristic acetic acid (vinegar, stop bath) odor as it deteriorates. Both nitrate base films and early acetate based films should be stored loosely with paper separators and not sealed in tight containers so that the decomposition gases can escape.

My conservation books don't provide a solution for tightly curled films on brittle bases.