Plaster of Paris and most casting plasters are great for casting toy dinosaurs, handprints and crafts at home and school for your kids, but the professional conservator needs a much higher quality product. You will find that most casting materials mix at a ratio of upwards to 100 parts water to 100 parts plaster. This can cause any number of problems when crafting larger casts. Due to the extra water, longer drying times are needed and the finished cast will have at best, half its potential strength. If dried to quickly, the cast can easily warp, distort and or generate stress cracks that will sooner or later cause the cast to fail.
Listed below you will find several casting media that we have selected to offer conservators. These products are specifically designed to eliminate many problems that can arise from casting small losses to the largest of reproductions.
Hydrocal-White is a gypsum based cement that is several steps above White Art Plaster in overall performance. It has almost no expansion, combined with great hardness and strength (5,000 psi). Furthermore, Hydrocal-White will produce a cast with an excellent fine detailed surface. Upon hardening it can be drilled, filed, stained and painted. Hydrocal can be carved or added to if needed. Setting time is approximately 30 minutes. Casts can be made from most all molding materials. The mixing consistency is 45 parts of water to 100 parts of plaster.