This is what’s left of the rubber feet of my 1994 Commodore Amiga 4000/040.
Yep. That’s a viscous tar-like residue that ran along the bottom of the case and into the gap between the bottom case and the cover. It’s very sticky and resistant to detergent, but, fortunately, not to citrus-based sticky tape removers. Isn’t it gross? I mean, seriously, doesn’t this look like some sort of OOZE OF SATAN special effect?
Oddly, the stickytape used to hold the rubber feet on was intact! And, as far as I can tell, fine. This actually saved me a lot of cleanup, because the cores of the old feet were pretty solid? The further I removed down, the more like rubber it became. The thickest material had an actual rubber-like consistency.
Fortunately, all the rubber that ran could be cleaned up pretty easily with an old spudger and a lot of orange oil. But goddamn.
I’ve repaired tube equipment from the second world war and this is the most bizarre materials degradation I’ve ever encountered.