How to Make Liquid Plaster

To make long-lasting plaster castings, you must first start with liquid plaster.

Liquid plaster is poured into rubber or clay molds to create plaster castings. If liquid plaster is allowed to dry into a harder paste, it can be applied to surfaces with a trowel. If it is allowed to cool more, it will be a solid block that can be carved with a knife. Plaster is made from the calcination of gypsum and has been used for thousands of years in construction and to make castings. Plaster can be in many forms. Plaster is highly durable, as long as it is kept away from frost.

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Plaster powder
Mixing bowl
Water
Large mixing spoon
Measuring cup

Instructions

- 1
  
  Mix 2 parts of plaster powder to 1 part water. If you need 3 cups of liquid plaster, for instance, measure out 2 cups of plaster, dump them in the bowl, then measure out 1 cup of water and dump it into the bowl. Stir with a large mixing spoon. While mixing the liquid plaster there will be a lot of bubbles.
- 2
  
  Tap the side of the mixing bowl with the spoon to get rid of most of the bubbles.
- 3
  
  Do not touch the plaster until the plaster has soaked up the water completely and the mound becomes damp.
- 4
  
  Mix the plaster mix quickly and evenly with the spoon so that there will be no lumps. You now have liquid plaster. Pour the plaster into your molds before it sets.

Tips & Warnings

The mixing bowls must be clean. Dirty mixing bowls affect the setting of the plaster, and bits and lumps of debris affect the finish. Because clay and other pollutants in the water will seriously affect the setting process of the plaster, it's important to use clean water. Avoid continuously stirring plaster; doing so will mess up the crystals that are trying to set.

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