I'm currently going through several boxes of reel to reel tapes (some acetate, some polyester) that may have been exposed to mold. There was a water leak where they were stored, and some of the boxes got slightly wet, so we're checking them to see if they're okay or not. So far, I've only seen mold on one of the boxes (the tape box, that is, not the larger cardboard box holding all of the tapes), and some of that got onto the outer layer of tape. The other tapes appear to be somewhat dirty and poorly packed in some cases, but as far as I can tell, no mold. I've been using a small brush to gently dust off what I've been finding, and my assumption is that if it brushes off easily, it's just dust, and mold would adhere more stubbornly.
Am I right about this? It's been a couple of years since I've seen truly moldy tapes, so I want to make sure I'm not overlooking something. If I look at these under a microscope, what magnification do I need to use in order to see actual spores (if they're there)? It's a little difficult going through these because it's apparent that prior to two or three years ago, these tapes were not stored in ideal conditions. (Which of course means they might have mold on them from years ago and not this recent water incident.)
--------- Trey Bunn Audiovisual Conservator Emory University Libraries Preservation Office Atlanta, GA 404-727-4894