Originally Posted by
cycle_maven
I think the rubber cement in stationery stores is enough different that you'll not get a patch to stick. The stuff in the patch kit is much thinner and probably has a different solvent mix to "vulcanize" the butyl rubber of the inner tube.
Contact cement is not the same even if it smells the same. Eventually contact cement will dry out and crack, where the rubber in inner tube patch kit still will be pliable.
It is not the solvent in the patch kit glue that participates in the vulcanization. It is only the natural rubber dissolved in the solvent. That is why the solvent has to dry before you can put the patch on the tube.
the rubber is useless until it is vulcanized in contact with both the tube and patch. The rubber that dries out has reacted with air instead of the vulcanizing agent. That's why it dries out. It has been oxidized. But after vulcanization the reactive sites which can be oxidized have been used up and are no longer available.