Cleaning old negatives

[juan]

I am going through my ancient B&W negatives for a process that is unmentionable on APUG. I am finding negatives that are about 40-years old, and that were stored in the glassine envelopes sold at the time, have aquired a gummy coating of something - probably a combination of something outgassing and the high humidity where I live. On a blank frame, I tried wiping with a microfiber cloth, and the gunk will come off, though I had to wipe so hard I'd be afraid of scratching an emulsion. I've searched the Internet for film cleaning advice and find that the harsh chemicals once used to clean movie film are now banned.

It would seem to me that I could rewash the negatives, perhaps with a bit of dish detergent, wipe them gently with my fingers while in the water, then hang and dry.

Any comments or suggestions?
juan

 

[jeffreyg]

Juan,

There is a product for cleaning negatives called PEC 12. I have used it on occasions successfully but I would recommend trying it on an unimportant negative first. I keep my negatives in archival sleeves but have some equally old ones that have been in glassine sleeves that have not had any problems despite our high humidity albeit our ac is on most of the year.

http://www.jeffreyglasser.com/

 

[Jim Noel]

soaking in LFN or weak solution of detergent, then wiping gently while underwater usually helps.
My problem with using PEC 12 is the strong possibility of minute scratches.

 

[Paul Howell]

On occasion someone pays to reprint old negatives, my first approach is to lightly clean with Enwall Negative cleaner using a cotton ball. If the negatives are in really bad shape, dirty, water damage I find it best to scan and restore with software rather than risk damage by rewashing the negative. If I cannot get a good scan I will print as it then scan the print for restoration. In days before digital I attempted to clean a negative damaged by smoke, the emulsion came off when I washed it.

I also have negatives now 45 close to 50 years old in the old glassin wax paper files and never had an issue.

 

[Sirius Glass]

When you complete your unmentionable process do not throw out the negatives. They are much more archival than the unmentionable process.

 

[fotch]

The unmentionable process is not archival.

 

[Doremus Scudder]

If the negatives are not "damaged" but just dirty, a water wash should not harm them. Test one that you have a duplicate of or that's not that important. Don't use dish-washing detergent; Photo-Flo or other surfactant made especially for photography purposes is best. FWIW, I've washed century-old glass plates with no problem. That said, if the emulsion has been compromised (dissolved, invaded by mold, chemicals, etc.) then washing may well loose it from the film base. Test one.

I've not used the PecPads; many swear by them.

The old carbon tetrachloride and trichloroethane film cleaners are gone. The Edwal cleaner seems to be based on another, safer solvent, tetrachloroethylene. The msds is here if you're interested: https://www.freestylephoto.biz/pdf/msds/edwal/Edwal_Film_Cleaner.pdf Kodak lists it as number one on their list of alternative solvents for film cleaning here: http://motion.kodak.com/motion/Support/People_And_Planet/Product_Use/solvent.htm

I've used naphtha (lighter fluid) in a pinch as well as alcohol. The Kodak site linked to above likes naphtha too, but I'm not sure how pure the Ronsonal I used was

Maybe someone more versed in film conservation can chime in.

Best,

Doremus

 

[Tijmendal]

The unmentionable process is not archival.

I'm baffled why this notion is so widely accepted. When you do the unmentionable process and store the outcome product as that one thing that rhymes with duck egg I honestly don't see how they could ever be lost. Sure, if you use one place to store them, that's dangerous. But the beauty of the unmentionable process is that you can make an infinite amount of copies without reducing the quality.

 

[Sirius Glass]

I'm baffled why this notion is so widely accepted. When you do the unmentionable process and store the outcome product as that one thing that rhymes with duck egg I honestly don't see how they could ever be lost. Sure, if you use one place to store them, that's dangerous. But the beauty of the unmentionable process is that you can make an infinite amount of copies without reducing the quality.

Changing formats, changing operating systems, charge migration on digital storage media, ... this has been beaten to death on APUG. Just do some searches on APUG and about how NASA has lost all its pre-Apollo landing site surveys.

 

[hack02]

Scanning fluid does the best for me. The kind derived from kerosene (lamp oil) not naphtha. If these are colour films (not chromes) a dip in c-41 stabilizer after cleaning would be advised.