Originally Posted by
cyccommute
Heptane doesn't do anything for "vulcanizing". Vulcanizing is the process of adding sulfur to the rubber to cross link it and harden it to make it more durable. The accelerator present in the vulcanizing fluid of a Rema system does cross link the existing polymer. Rubber cement does not. Rubber cement is simply a surface adhesive.
The answer was found long ago. See post 30 above. Some people are just cheap.
Nowadays vulcanizing means crosslinking rubber with sulfur or many other chemical agents. I suspect the crosslinking agent is incorporated into the patch and the vulcanizing rubber cement contains the accelerator to make it all go at room temperature. The solvent in the rubber cement helps spread all the chemistry around. The rubber in the cement bonds to the patch and to the tube and holds the whole thing together.