Plaster Mold Casting

Plaster mold casting is just like the sand casting, the difference is that the plaster of Paris is used instead of sand in mold making. In plaster mold casting, plaster of pairs is mixed with a fixed quantity of water to make a mixture which became rock solid in few minutes.

Steps involves in Plaster mold casting

Step 1

The first step is the making of the mixture. Plaster of paris is mixed with water or some other binder to make a thick mixture which become solid in few minutes

Step 2

Pattern is made of wood usually and sprayed with the thin layer of parting component in order to prevent the sticking of mixture with pattern

Step 3

Mixture is then poured onto the pattern and make sure that the pattern is completely  covered with mixture.

Step 4 

After the plaster is set. Patter is removed from the solid plaster

Step 5

Mold is not yet perfectly dry that’s why it is heated at 120 C to remove the excess water

Step 6

All the pieces of the mold are assembled and preheated and then molten metal is poured in the mold

Step 7

After the metal solidifies mold is broken to remove the parts

Advantages of Plaster Mold Casting

• Better dimensional accuracy 
• Good surface finish

Disadvantages of Plaster mold casting

• Slow process
• Moister effects
• New mold is needed every time for Plaster mold casting
• Mold Plaster mold casting will brake if over heated