SMOOTH-ON SMOOTH-CASTÃÂ® 305 - SLOWER CURE TIME Smooth CastÃÂ® 305 liquid plastic is an ultra-low viscosity casting resin. Does Smooth-cast 300 cure too fast for you. Problem solved! Smooth-Cast 305 cures slower than Smooth-cast 300 with a 30 minute demold time and 7 minute pot life. It yields castings that are bright white and virtually bubble free. Vacuum degassing is not necessary. Smooth-Cast offers the convenience of a one to one mix ratio (one part A to one part B by volume). Fully cured castings are tough, durable, machinable and paintable. They resist moisture and mild solvents. Applications for Smooth-CastÃÂ® Liquid Plastics include reproducing small to medium size sculptures,making prototype models, roto cast pieces, and special effect props. For rotational castings, cheque out Smooth-Cast 65d!