Well, let just say sometime you succeed and sometimes you learn from your mistakes. I spent about 2 weeks creating a head for our jack skelington figure to go on our roof. Paper mache base, epoxy for around the eyes and joint compound around the mouth. I found out the hard way when torential rains came down that it was not sealed properly.
Step 1: What Did We Learn????
I believe my problem was not sealing it completely with joint compound and using spray paint instead of a latex paint brushed on. Just have to reconcstruct a new one. Leasons learned.