What is Plaster of Paris and How to Make it at Home?

Plaster of Paris Recipe

Plaster of Paris is a Calcium sulfate semi-hydrate (CaSO₄,½ H₂O) derived from Gypsum, a calcium sulfate di-hydrate (CaSO₄, 2H₂O), by firing this mineral at relatively low temperature and thus reducing it to powder.

CaSO4,  2H2O  + HEAT -------> CaSO4, 1/2 H2O  + 1.5 H2O

In 1700’s, Paris was already the “Capital of plaster” since all the walls of wooden houses were covered with plaster, as a protection against fire. The King of France enforced rule after the big fire in England 1666.

Large Gypsum deposits near Paris ► Mined ► Manufacture of Plaster of Paris

Watch Video on How to make Plaster of Paris Step By Step Guide

Items Needed

(Apparatus) to make plaster of Paris with glue

• 2 parts Diluted White Glue
• 1 part Warm Water 
• Large Mixing Bowl
• Spatula or Wooden Spoon

Instructions and procedure

• Gather all the materials and spread a sheet on the work surface.
• Now, pour the glue in the large mixing bowl and beat it well.
• Make a paste, by adding one part warm water to two parts of white glue.
• Mix the ingredients well. Continue stirring them, until there no visible lumps remain.
• If you do not get a soupy mixture, you can add more water to the bowl and mix well.
• The final product should be watery, but with a slight white glue consistency.