Originally Posted by
RubeRad
All the glueless kits I see still come with sandpaper to roughen the surface of the tube. Does that possibly mean that the glueless patches are pre-glued with vulcanizing glue? Or just that the unroughened surface is just plain no good for adhesion
Similar to glueful (?) patches. Tubes are produced with an outer layer that keeps them from adhering to the tooling. That mold release layer also keeps anything else from sticking. You have to sand (or file, or grate) that layer off -- not just get the surface rough -- before anything will stick to the tube.