I have some Liqua Cast that is probably six months old. Used it this morning to cast a duck head and had major air bubbles. Its like this stuff kicked off really hard with a lot of air bubbles and pretty good expansion. My mold was made with Smooth-On PMC-744. I use Synlube 531 as a release. Does this sound like a moisture problem? Note: I made a bondo/resin cast and it came out fine. Now I know my mold is good.