David Boyes <[EMAIL PROTECTED]> wrote: > Does anyone still know of a source that sells 3420 cleaning fluid and > supplies? In the process of working through these old tapes from > Princeton, I'm burning through the small supply I have of the stuff > rapidly (2 pints so far), and still have a few thousand tapes to go.=20
The popular cleaning fluids are mixtures of isopropanol and 1,1,2 Dichloro 1,2,2, Difluoro ethane, I believe called Freon TF. I have no idea if that is what yours is, though. Ordinary rubbing alcohol is 70% isopropanol, but many stores (grocery stores or drug stores) also have 99% isopropanol. If you have a near by chemistry lab you can get reagent grade, which is probably 99.99% or so. (Not counting the water that will get in as soon as you open the bottle.) > The amount of oxide flaking and just general destruction these tapes > have is amazing - gunk everywhere. Hats off to the data recovery folks - > I'd really hate to have to do this all the time. Freeze drying, careful > rereading, multiple retries... sheesh. Phase of the moon for some of > these volumes.=20 Are you warming the heads? I have heard over the years that it the favorite way to reduce flaking. The first time I heard that one was an article in Popular Science about a video tape recorder that used 0.25in tape linear recording at 120in/s. (Many years before Beta, or even U-matic.) Warming the heads was necessary to prevent scraping the oxide off even of new tapes at that speed. There is also supposed to be a last chance system that uses a fluid, such as cleaning fluid, on the head while reading the tape. As I understand it, it only works once. After that, the tape is ruined. I have never tried, or even seen this done, though. -- glen
