Ran into something this week I never saw before. GE Silicone Caulk can go bad. I've had it dry up in the tube all my life but never go bad. I had a tube which the caulk had hardened in the tip where I couldn't use it in the caulking gun so I took a utility knife and cut the tube open and what was inside seemed to be fine. I used it and after two days it's not even dry to touch. I'm going to have to clean it off and start over.