I'm having alot of air bubbles when pouring and when cooled the wax is shrinking away from sides. Im not sure what Im doing wrong or different. I use cement vessels with some acrylic paint thru out the vessel. My home is around 74*F, wax is around 220*F then mixed with FO stirred for aprox 1-2 minutes then poured in vessel on raised rack covered with cardboard box overnight to keep drafts off. Anyone got any tips tricks or suggestions on what Im doing thats creating all the air bubbles and shrinkage?