Trapper Don

I made a 4 bay mold maker (we make a lot of molds) and pour a lot of plaster. If you mix your POP thin, your working time is longer, your air bubbles come up easier and... if you put a vibrating orbital sander underneath the mold your bubble problems are gone. (99.9%) But that works with our setup because its heavy. If you are making them one at a time the mold may be too light and bounce around on top of the sander. Im sure it could be modified.