YAY! It worked! The plastic is set. God saved me!
I painted the small sculptures after applying white base primer.
Paints are Benjamin Moore’s outdoor water based flat colors. This is the first time I use American paints, and I found something interesting. In Japan, I mixed complimentary colors to get duller color. The more colors I mixed, the duller the color became. But American paints seem to retain the color purity even after several colors are mixed. I originally planned to make the surface very smooth, but because of the troubles, it turned out to be little bumpier.