Saving your family History

Every family owns a box of old slides. Somewhere in the garage, or storage unit, even in the back of the cupboard are memories you may have almost forgotten about. While that's a sad thought, what's even worse is the very possibility this part of your family history is deteriorating every day. Mould and mildew are your slides worst enemies and chances are your precious memories already have some degree of mould growing. The good new is this process can be stopped. Here's a great article from Stanford University. It outlines the Freezing Process of Mould removal and an inexpensive and very effective way to preserve your slides. We strongly recommend that before you attempt this process at home, have your slides scanned in their orgianl state. For whatever reason this freezing process does not work at least you have copied your slides (in high resolution).

*We accept no responsibility for damage to your slides whilst attempting this process 

Preliminary Report on the Conservation of Slides with Special Reference to the Removal of Mold
By Niccolo Caldararo and Candis Griggs 

Perhaps millions of slides have been made of art historical materials, archaeological sites and objects, scientifically important procedures, historical events and a vast number of other types of information of significance. A great number of these slides have entered into collections for a number of diverse reasons. The durability of the slide depends on the emulsion, carrier and slide frame. These materials have changed over time, from glass to plastics for the carrier and from metal to paper and plastic for the slide frame. In many collections, varying humidity or accidents have caused damage to one or all of these components. Because of the fragile nature of these materials, the slides are often damaged beyond repair.
One of the main agents of this damage is the growth of mold on the surface of the slide, specifically on the emulsion. Removal of this growth has been difficult without severe damage to the emulsion and image. There is little information in the literature to guide the curator or conservator in this problem. Our research has led us to the chitin building blocks of the mold and its essential relationship to the emulsion, considered in basic regard as digestion. Taking advantage of this relationship, we have devised a method of removing the mold bodies which results in little or no observable increased damage to the emulsion and image.


Slide before Treatment Slide after Treatment

Successful removal usually required the following procedure. The slides were placed on a plastic base in a refrigerator freezer at or below freezing temperature. The slides were removed when a film of moisture could be seen to have accumulated on the surface. They were then swabbed with a Q-tip, removing all the moisture and fungal colonies with one tip, and then quickly buffing the entire surface with the other (see before and after illustrations in Figs. 4a and 4b). Sometimes this had to be repeated two or three times. If the first removal was not done carefully, some chitin would be deposited along the edges of the slide against the frame, and could be seen as a margin in raking light. The initial cleaning is often so remarkable a change that the operator often believes the surface has been completely cleaned. Careful examination under raking light will often detect streaking, which is a film of incompletely removed chitin, in our opinion. Second or third attempts often remove this film adequately.

Our experiments and preliminary work indicate that this procedure can clear most slides of fungal colonies without detectable damage to the emulsion. The variable success of removal needs to be studied to find whether the variation is due to different fungal species, temperature at the workbench, extent of damage to the emulsion, or operator error or variation. We also need to apply this technique under experimental conditions to a greater variety of slide type and manufactured product over time. At present our results can be only applied to slides manufactured between the 1960s and 1990s. We do not recommend its use with slides older than this period. Slides treated thus far have mainly been Kodak products (Kodalux, etc.) and many unidentified types. When we showed our results to Hanna Szczepanowska, she suggested that the variation in cleaning we reported might be due to the way different species of mold attach to the substrate, since these are anchored by different structures into the gelatin. Her 1986 article describes these differences and we are at present hoping to collaborate in the future with her to clarify this condition. We hope our efforts can help others in the conservation of slides and we are very interested to hear from other people who have tried any and all methods in this endeavor.

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