cleaning glass plate negativs?

[hendrik faure]

I prepare glass plate negativs from 1925-1940 (mostly Agfa extrarapid and Agfa isochrom) for scanning, some of them rather dirty.
Glass side no problem. What can be recommended for the coated side?
Thank you

[Nodda Duma]

Are they already exposed? The only thing I can think of is to re-rinse in a tray with light agitation in running water, final rinse in photoflo solution (like for film) then set vertically in a rack to dry as if they were new.

But obviously there's a risk and you'd want to test this method first before going hog-wild. Keep the rinse temp below 68F (65 is better) and make sure the plates are at the same temp before putting them in the rinse bath.

[Greg]

Have scanned hundreds of glass plates dating from 1880 to around 1910 for our museum. Some were dirty. On the glass side, Windex spray and paper towels. On the emulsion side good olde Kodak film cleaner and an Ilford Antistatic cloth. Cleaner is highly flammable and can't be all that good to breath in. I'm sure hasn't been sold for years, but I found several bottles at a State Surplus Store. The address on one bottle was pre ZIP codes!

[Nodda Duma]

Better suggestion than mine, Greg!


Edwal anti-static film cleaner is available new.. Do you think that's the same or similar stuff?

[Greg]

Better suggestion than mine, Greg!


Edwal anti-static film cleaner is available new.. Do you think that's the same or similar stuff?

reading off the label on the Kodak film cleaner bottle: "Contains: 1,1,2-trichloro-1,2,2-trifluoroethane (76-13-1),and heptane (142-82-5)" and the: "DANGER! FLAMMABLE LIQUID AND VAPOR. HARMFUL OR FATAL IF SWALLOWED". And to think we used to use this on a daily basis leaning over a light table in the 1970s thru the 1990s!!!

[LabRat]

I think Pec-12 is still available, and has worked well on some vintage materials... (Test anything before you use...)

Re-washing plates usually leads to frilling/peeling, so I would avoid it, but you can look up pre-hardeners in older photo books (usually formalin based), but usually if you wet and try to remove a spot, it will lift the emulsion up with it, so maybe just solvent based stuff...

Steve K

[Bill Poole]

I've used Pec-12 solution and wipes to clean 100-year-old negatives with some success. But of course, test, test, test.

[mmerig]

I've used Pec-12 solution and wipes to clean 100-year-old negatives with some success. But of course, test, test, test.

I have some of the old Kodak cleaner, and use it sparingly on film. Usually, I use 95% alcohol, and it works as well, and is much safer to human health and more available. I have never worked with old glass plates. What would work on your dry plates, Nodda Duma? Someday I may try your dry plates, so it would be good to know.

[Nodda Duma]

Should work the same.

Prevention is the best cleaner.

[Doremus Scudder]

One thing to keep in mind. Portraits and even some landscapes made on glass plates were routinely retouched, usually with graphite pencil. Any cleaning may remove the retouching. I cleaned retouching off wedding anniversary portrait plates of family members from the 19th century in order to see the character of the faces (i.e., wrinkles) that were otherwise smooth, but that was intentional. (Made great contact prints from these, BTW...). Anyway, retouching should be visible if you hold the plates at glare angle to a light source and examine the emulsion side.

As for cleaning, I've rewashed glass plates in running water and used film cleaner, both with good results. However, the plates I had were in really good condition; no chipping, frilling or mildew. If there is damage to the emulsion side, I'd be really careful with water.

Best,

Doremus