Developed Negatives in the Refrigerator?
I always store my unexposed color film in the refrigerator, and allow a few hours for it to get to room temp before I shoot it, but what about film that has been developed? I know the Library of Congress stores their non-nitrate films at 25F degrees with 30% relative humidity for a crazy shelf life of something like 2000 years. This brings me to think that archiving my developed negs in the refrigerator would be a good idea, but is it still as effective with the fridge being opened and closed all the time for it's main purpose of storing food? Won't the relative humidity change so drastically that it might void the benefits of constant and consistent temp/humidity?
I just want my negs to last my lifetime, and if standard home-refrigerator storage will at least increase its preservation index, I'm willing to designate a good portion of my fridge to store my work.
Thanks for you input
Stored in acid-free sleeves at room temperature, in relatively stable humidity and total darkness, your negatives should outlive you by a hundred years at least. There's no need to put them in the fridge, in fact, I would avoid this. Fridges provide very unstable conditions and usually contain lots of bacteria cultures that you wouldn't want on your negatives, even if the cold slows them down.
Save that fridge space for fresh film, you're going to need it.
And the sign said, "long haired freaky people need not apply"
If you want to do this, dedicate a separate fridge just for this purpose so you don't open it all the time. When no food is stored, the bacteria won't be a problem, either. Still, clean thoroughly every now and then, e.g. twice a year, and store some silica gel (get it in large amounts from Ebay) there just to make sure the RH does not rise for any reason. Check the silica gel indicator color every few months and regenerate if it shows any moisture buildup.
You should still consider the fact that most refrigerators have comparably large temperature swing (hysteresis). I don't know if this is a problem or not but it may be worth considering. You may be able to counteract some of the hysteresis by storing a large (closed) bottle of water there.
And, avoid storing any negatives near the evaporator (the cold "heatsink") and directly underneath it. It is normal that condensation occurs there (it ensures the RH does not rise (that is, hopefully, at least not very much), by condensing excess moisture from the air into water!), but you don't want any condensated water drops to touch your work. Also, the temperature gradient is highest near the evaporator.
Last edited by hrst; 04-09-2012 at 07:41 AM. Click to view previous post history.
mortenson processed his film in his refrigerator "to completion"
i don't think he did anything fancy, just removed the light bulb..
From Image Permanence Institute, Rochester Institute of Technology
Acetate film will begin to seriously degrade in about 50 years at room temperature and moderate RH. Periods of higher temperature or dampness will accelerate the process; cold and dry periods will slow it down. Newly processed film stored in cool (72°F/21°C or less) or cold (50°F/or 10°C or less) at moderate RH (20% to 50%) can be expected to last for centuries. The same film stored under poor conditions may last only a few decades. Color film benefits doubly from cold storage—the film base is stabilized and the rate of color dye fade is minimized.
and more, an article as pdf Vinegar Syndrome: An Action Plan by Jean-Louis Bigourdan, Image Permanence Institute, Rochester Institute of Technology
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Elaborating on the fridge storage problem;
You should note that there is a possibility that the fridge makes things worse. This is because of the RH. If you just cool air down, the RH will rise; so, you should lower BOTH temperature AND RH, or at least keep the RH from rising; either way, when lowering the temperature, you need to decrease the ABSOLUTE humidity, by removing water vapor from air.
In a fridge, there is a large temperature differential. The evaporator can be at freezing point or even below. When the humid air cools down, the RH rises until it hits 100% and condensation occurs. Luckily, because of the large temperature differential in a fridge, RH is 100% only at the very surface of the evaporator and the condensation occurs there. As the air gives off the water vapor there, the absolute water content of the air falls down, keeping the RH from rising. In a lucky situation, the RH may even decrease, and that should be your goal.
The last thing to do is to add a fan to circulate air in the fridge. This way, the temperature differential is removed, no water is condensed on the evaporator and the RH is sure to rise considerably and may hit 100% everywhere and start condensing on the walls and on your work. So, you want the evaporator to be as cool as possible, condensate as much water as possible and have your work as far away from it as possible. You can even have a very low-power (just a few watts!) heater on the opposite side.
The silica gel I mentioned before is a simple way to dry the air, but I would go with at least a few hundred grams and try to spread it on a large, open area. (for example, see http://www.ebay.com/itm/ST-ORANGE-SI...ht_3976wt_1346 ) When it changes the color, you can regenerate it by heating in oven at about 150 deg C until it's back to normal color. The microwave can be very quick, be careful if you're going to use that one.
Luckily, when you don't open the door often, no humid air gets in. This way, the temperature differential inside the fridge may be enough to keep the RH very low. In any case, I would consider adding a cheap digital RH meter with a sensor cable to monitor the RH and temperature without opening the door.