This article is from the 8-track Tapes FAQ, by Malcolm Riviera malco@interpath.com with numerous contributions by others.
This is one of the most common repair jobs with 8-tracks. The metallic
strip is located at the splice that holds the two ends of the tape
together, and this is where tapes often break. And sometimes the foil
strip just wears out without breaking, causing the same track to play
over and over. Radio Shack still sells rolls of the foil sensing tape,
believe it or not. You can get a small roll for a buck or two, and
it's already cut to the proper width for 8-track tape. Just use a
razor blade to cut a piece to the correct length. It's adhesive on
the back and attaches to the existing tape easily. Make sure you put
the metallic tape on the shiny side of the tape (the side facing the
playback head) or it won't work!
 
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