Quote Originally Posted by Panomaniac View Post
Never really dries (hardens) is good. Gummy is not.
There is a differance between drying and hardening. Silicone glue dries* but it doesn't harden. A lot of the undercoating in spray cans is just nasty for use on horns........ it doesn't even do a good job on cars.

* I suppose it could be a chemical reaction, but most people talk about stuff like glue and paint drying no matter if it's a chemical set or evaporation.