I am interested in making a vacuum pressure chamber that I could use to pull the air bubbles out of my casts before/as they harden. I have seen a few and think it seems fairly easy to do. I think I would need a pressure gage (not sure what kind), a base that is attached/sealed with the tube like chamber (one that would be big enough for the size of molds I have). A spot to vacuum out the air, and a lid. All would need to be air tight. Anyone out there who has made one or has plans for one that can be made for under $100?