AeroMarine Products is proud to sell Ultra 4 Urethane Parfilm Mold Release.  Spray inside of your mold to quickly and evenly coat it with an invisible film that will allow you to effortlessly remove your cast urethane object.  The parfilm takes a few minutes to dry once applied, so you can paint it with a brush as well to make sure you get all the nooks and crannies.  Be sure to give it time to dry and for the propellants to evaporate once applied.