I remember hot patching bike tubes where you light the glue on fire and stick the rubber patch on, but never anything as series as these with a clamp and the steel backing!
For what it's worth, I kept two of them in the can and through the rest out. The were all nasty crusty anyway.
Here is my Sunoco tire patch collection. These larger ones are the only examples of these I've ever seen.
Last edited by Steven C.; Sun Mar 22 2020 07:32 AM.