I beilieve its for Room Temperture Vulcanizing. Basicly, your sealant will change state and cure without additional compounds, the air does it for you.
- Vulcanization can also be accomplished with certain peroxides, gamma radiation, and several other organic compounds. The finished product is not sticky like raw rubber, does not harden with cold or soften much except with great heat, is elastic, springing back into shape when deformed instead of remaining deformed as unvulcanized rubber does, is highly resistant to abrasion and to gasoline and most chemicals, and is a good insulator against electricity and heat. Many synthetic rubbers undergo processes of vulcanization, some of which are similar to that applied to natural rubber. The invention of vulcanization made possible the wide use of rubber and aided the development of such industries as the automobile industry.
Ray Reynolds
Senior Designer
Read: faq731-376
"Probable impossibilities are to be preferred to improbable possibilities."
As stated earlier, RTV stands for Room Temperature Vulcanising.
In practice, compounds called RTV are in general silicone sealants that come in a tube and which set to become a rubbery solid after some time (due to exposure to moisture in the air).
There are other methods of turning the silicone goop into a solid (a process called polymerisation). Two of these are: application of heat; addition of a catalyst.