How long does plastic roofing cement take to dry?

I used Black Jack roofing cement to fill a small gap where a piece of flashing was missing. I put a pretty good size bead/glob to ensure I filled in the small gap and the gap between the roof and the bottom piece of hardiplank. So, you can imagine how thick it is. It has be a good day and a half since I have done it and it's just as wet as when it came out of the tube. Is this normal? And, if it stays like will the force of a heavy rain mess the bead up? Thanks for any input!