How to make home-made plaster molds

It is such an enjoyable task when you mold plaster into the shapes that you desire. If you have children, it gives very good bonding time with them when you train them how to mold different figures and sizes.

Perform Time

40-50 minutes

Tools and supplies needed:

2 Cups of water

3 Cups of all-purpose flour

Popsicle or Wooden stick

Bucket with a plastic garbage bag

Getting to work

Warm two cups of water and stir slowly in 3 cups of white all-purpose flour. Continue stirring and remove any lumps. Ensure that it forms a smooth pudding texture.

Pour the plaster into mold and tap the bottom of the mold against a flat surface. This will ensure that all the trapped air is eliminated.

Smooth the surface with a wooden spoon or Popsicle stick. The mixture will begin to harden immediately.

Allow the mold to sit in a warm dry area to dry overnight. Once the plaster is dry, it is ready for use.

Line a rinse bucket with a plastic garbage bag and fill it with water.

Use fresh clean water. Either distilled or drinkable tap water is the best. When metallic salts such as aluminum sulfate are present, they accelerate the setting time and soluble salts can cause efflorescence on the mold surface.

Use fresh plaster because it is calcined. Calcined means that chemically bound water has been eliminated from it through heating. If plaster stays in a damp environment, it will develop lumps thereby rendering it unusable. Therefore it is recommended that you use dry, lump-free plaster.

Weigh the materials so that you can use the exact amount you need. In order to have a consistent mixing process and not keep adjusting the quantities.

Add the plaster to water. Sift it slowly onto the surface of the water. This process will take less than 30 minutes. Avoid dumping the plaster or tossing it in by handfuls.

Soak the plaster- Give the plaster 1-2 minutes to soak. This will allow every plaster crystal to be surrounded by water completely thereby removing all air from the mix. Please give it enough time to soak since incomplete soaking may lead to the formation of pinholes. On the other hand if the soaking takes longer than is required, it will cause early stiffening and gritty mold surfaces. The smaller the batch, the lesser the time needed for soaking.

Mixing the plaster

Small batches of plaster can be mixed by hand. Use a constant motion with your hand and the mix will slowly change from watery to a thick cream. Break down lumps by hand as you mix. Take little time so that you do not agitate the mix to allow air inside.

There you will have the finest plaster to mold the shapes that you desire.