Gooey tape rollers - how widespread is this problem ?

The drive rollers on QIC drives are the most troublesome. Most of the DC300 drives I have are bad. All of the Apple Tape Backup 40's I've ever run into are bad. Most HP DC100 drives are bad. Same for all of the pre-QIC DC300 drives used in Tektronix 405x's, DEI drives in Onyx systems, TI drives, etc. etc. Pretty much all of the drives from before 1985 are bad. No one was thinking about trying to use these things 20+ years after they were shipped. 1/4" cartridge drives are common enough that there are still maybe one in ten that have good rollers. Wangtek is more difficult to repair than Archive, since Archive kept the same roller design for 10+ years, so you can still find later drives that can be cannibalized to fix old ones. It should be possible to use rubber tubing of the right diameter and gasket cement to fix the HP drives. Brad Parker gave me a 1 foot piece of rubber tubing that is the right diameter for TU58 rollers. TK50s have problems with the tapes going sticky. Because of the way the carts are built, I've not found a way to safely dehydrate the tape binder. I have hundreds of DC300 carts that I'm trying to go through that all exhibit some degree of stickiness. Because of how thin this tape is, I'm a bit nervous to use the same dehydration oven I've built for processing 1/2" tape http://www.bitsavers.org/tools/oven