During the 1970's-80's 3M Scotch used a foam inner backing beneath the top reel flange on the 400, 420, 479, and 8250 videotape products to reduce edge damage.
  At some point, a different type of glue was used that would not set-up and dry, and leaked onto the tape surface creating a tremendous sticky mess.
   3M made a valiant effort back in the day to replace all the affected flanges with the defective glue, but it was a very popular product and was distributed worldwide before the glue problem was fully realized.
   There are a few reels out in the world yet with the defective foam glue, sitting on library shelves. How many, nobody knows.
   Foam flange reels arrive here at the shop for transfer on a regular basis and most are generally in very good condition.
   Occasionally a reel will turn up with the "Flange Glue Syndrome" or foam decomposition problems.
   The photo gallery at left are images of tapes with various glue and foam problems that I have worked with over the years.
   It may help someone to better understand and identify tapes with these problems.

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