Can plaster of Paris manually mold in hands like clays?
plaster of paris does not have the same plasticity as clay does, it needs to be supported in a mold whilst it cures, also plaster of paris is an exotherm which will emit heat energy as it sets. The paris mix can stay liquid for up to 45minutes (in new plaster) but will set quickly after that time, when mixing older plaster (exposed to air) the set times are severely reduced from anything between 30 minutes and 5 minutes depending on the age of the paris powder. Because of its very fluid nature when first mixed and the fact that air must be thoroughly expelled from the mix; plaster of paris is an unsuitable medium for hand molding as its “setting stickyness” will adhere to skin makng any real shaping very difficult to achieve if not near impossible. Also the caolin additive in plaster of paris can cause irritation and soreness to the skin whilst moisture is present or before full evaporation occurs.
