Cleaning old glass plates

[wiseowl]

I have been entrusted to print some 1/2 plate glass negs.

Does anyone have any experience of cleaning glass plates? I'm thinking along the lines of cold water with some photoflo added.

Any thoughts?


Cheers

Martin

 

[DKT]

i'd probably just leave them alone...or try to carefully brush off any loose dirt--be careful if the emulsion is falking off though. you could use a solvent film cleaner--but you'd have to test a little area first, but the problem I guess would be if the plates had been varnished at all in any way--the solvent would probably screw that up. if you use a film cleaner--it would be a laborious process of picking away at the dirt--you wouldn't want to just wash the entire plate or try to casually wipe the stuff away--because the emulsions on those old plates is oftn pretty fragile, not to mention the glass itself loses integrity over time & can get really brittle. if you wet them--well--depending on the material, the screw-up factor is high. some old negs & plates, you can never really rewet without damaging them, especially if there's any sign of mold in the emulsion. the base side though--you can clean the glass pretty easily...

I work with old plates, and can't say I've ever tried to "clean" one. I'm not allowed to do that sort of thing where I work--we have conservators for that, or the stuff gets farmed out to other conservators. It's just skilled work and it's risky--especially if the stuff is not yours to begin with. the best thing would be to make your prints, copies whatever first, then try to clean them if you must. At least that way, you have a backup. personally, I would leave them alone, unless they were my own property.


my opinions only/as always

 

[gainer]

I inherited a number of glass plate negatives made by my grandfather over 100 year ago, many of which were in terrible shape. My best results were obtained by scanning the negatives and retouching in a PhotoShop clone. The cleaning and retouching are very much easier in digital form. The digital prints can be in the form of negatives on transparency film or positives on paper or film. You can make film negatives from the digital positive transparencies.
The scanner I used is no longer available, but some reasonably priced scanners capable of up to 5x7 transparencies ought to be available.

 

[gainer]

PS.
If the plates were from the collodion era, don't use organic solvents like alcohol or acetone.

 

[Jerevan]

I would never use anything liquid close to glass plates, except maybe a slightly dampened lintless cloth (distilled water and if the dirt is very stubborn, a few drops of ammonia in the water) on the non-emulsion side. A soft brush could be used on the emulsion side, to carefully brush off any debris. Otherwise, let it be as it is and retouch in the scanning or printing stage.

And while I am at it, preferably glass negatives shouldn't be kept in their original boxes (nice looking as they may be) - they should rather be in acidfree, wrapped envelopes. And of course handle them with cotton gloves to prevent fingerprints which is a breeding ground for all sorts of bad things.

This pretty much standard procedure in the museums where I've worked.

 

[Whiteymorange]

A relative who was a professional photographer in the teens and twenties told me that he used citric acid for cleaning the emulsion off his plates. I found this out after he knocked over a large jar of the stuff looking through his basement for photo gear to give me! Big mess, but I ended up with a great Folmer Schwing 5x7.

 

[Neal]

Dear Martin,

I would suggest contacting the George Eastman house. You can request information via e-mail. (At least they provided this service at one time. Check their web site.) They take a few days, but someone knowlegeable about the subject should contact you.

Neal Wydra

 

[Allen Friday]

I suggest reading "Conservation of Photographs", Kodak publication No. F-40, CAT 193 5725. I read it several years ago before starting on a project to clean 300-400 glass plates found in an attic. It was very helpful, first in telling me how to identify the type of emulsion on the plates, then on how to clean each type. Great resource for learning restorative techniques.

Allen

 

[DKT]

the best way to store them, is actually to rehouse them in a four-flap envelope--store them vertically, separated to maybe 5 or so plates of the same size, in a sturdy flip-top, metal reinforced box....the thing is, to keep them from having any weight or pressure on them.

the four-flap envelopes fold in on top of the plate. there's a little bit of an indentation of sorts for the plate to rest in as well. you can move the plate around easier this way, actually, by holding onto the flaps of the enclosure instead of handling the plate directly. It also gets rid of the possible damage to the emulsion by sliding a plate in & out of an envelope. If the plate is broken--then you basically make a mount for it, and try to contain it in a small box by itself, and it's stored flat. it's treated more as an object at this point, than a negative.

right now the ones I'm most familiar with, come from Light Impressions--but just about all of the major archival/library suppliers carry 4 flap envelopes--or you can make them. I've been picking away at a glass plate project at work for a while now, and in addition to duping them, we're rehousing as well. we actually budgeted out for the enclosures in addition to the film & paper. there's really no point in just going halfway--making your prints and/or copies and not taking care of the plates. unfortunately, the cost of the enclosures will be right up there with buying photo materials.

 

[wiseowl]

Thanks for all the advice, initially I'll leave them alone and just make a print from each. Well, I'll probably give the glass side a gentle dust with a soft brush to remove dust first.



Cheers

Martin