Filed under "restoring a friend's old Korean War era Navy Band recitals." According to the American Chemical Society, reel to reel tape is prone to degradation, which has been a topic of active research for many years. It's well known that applying heat can often reverse the damage sufficiently to enable playback, usually by baking the tapes in an oven. Now scientists at the US Library of Congress have determined precisely why this method seems to work, presenting their findings earlier this month on the American Chemical Society's SciMeetings online platform. The primary culprit for the degradation is known as "sticky shed syndrome," in which the binders used in a magnetic tape to hold the iron oxide casing to the plastic carrier deteriorate. They form a sticky residue that can damage both the tape and playback equipment. [...] [E]xperiments showed that when a degraded reel-to-reel tape is heated, the sticky residues melt back onto the bulk polymer layer, rendering the tape playable once again. That's why 130F is the sweet spot for baking degraded tapes; it's the melting point for the residues. (This fix, however, only lasts several weeks. Plenty of time to digitize the media.)
Article
https://m.slashdot.org/story/370234