Mackey256 said:
… we found a trunk full of 16mm films while cleaning our my grandparents house.
Be sure to immediately open each can of film and smell for any hint of vinegar-like odor. Any reel with that odor, even faint, means it’s film is breaking down. Worse, the odor is really an acidic gas and can seep into nearby cans and start breaking down them as well.
Immediately isolate all vinegar-odor reels in another room with ventilation (clean garage, dry shed, vented basement). Remove the reels from their cans (sit them on top of their closed cans) for the gas to escape away from the film. The no-odor films should be placed in another room with the lids propped open for ventilation.
Here’s what the pros say:
University Of Illinois Library - Preservation Self-Assessment Program - Film
Storage Environment
Allowable Fluctuation: ±2°F; ±5% RH
. . . . . . Ideal Acceptable Temp. 0–32°F (-18–0°C) 33–54°F (1–12°C) RH [relative humidity] 30–50% RH 30–50% RH Storage Enclosure(s)
Container: Film is ideally stored in a vented inert plastic can. Vents allow the film to “breathe” an even air exchange (crucial for acetate). The enclosure may be plastic, non-corrosive metal, or archival quality paperboard. Dirty, rusty, non-vented, or dented metal containers will only heighten the potential for film damage. The container your institution uses will largely depend upon the environment.If storing film in a room temperature environment, vented containers composed of polypropylene or polyethylene are optimal. If you are storing your film in freezing temperatures, your cans should be sealed and moisture-resistant. In any case, cans should be clean and free from debris, rust, and structural damage. When freezing film, ensure that the the film is properly housed by double-bagging it in zip-sealed freezer bags.
Core: Film should be stored on a core, which is ideally made from inert plastic, rather than on a reel. For 16mm and 35mm, the National Film Preservation Foundation (NFPF) recommends that the core be at least 3 inches wide. A wider core diameter lessens stress on the film as the film will not be wound as tightly. Smaller film gauges may be wound on smaller (less than 3") cores. A core is distinct from a reel. A reel is a metal or plastic hub with extended sides between which the film is wound for projection. Reels — especially metal, dented, or otherwise damaged reels — are NOT appropriate for long-term storage.