This tutorial shows how you can make a hollow resin casting using the semi rigid urethane plastic - Smooth-Cast® 57D. Smooth-Cast® 57D is a semi-rigid urethane plastic that offers a gradual cure profile (does not snap cure), making it suitable for machine or hand rotational casting.
Once poured into a suitable rubber mold configuration, the mold can be rotated so that the resin mixture gradually coats the inside of the mold cavity. After an adequate wall thickness is attained inside the mold, the result is a cured hollow casting that is semi-rigid and highly impact resistant.
Smooth-Cast® 57D can also be used as a casting resin for making solid, semi-rigid castings that are tough and durable.
Mix ratio is 1A:1B by volume. Working time is 3 minutes, demold time is 30 minutes and full cure properties are attained after 24 hours. Color is white translucent and the material is very easy to color with SO-Strong®, UVO® or Ignite® colorants. Cured resin is also easy to paint with acrylic paints or UreCoat® flexible coating for applications requiring thick,