Things You'll Need:
- Plaster bandage
- Petroleum jelly
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Step 1
Who forgot the mould release?For the purpose of description we will take a plaster cast of a foot. You need to put a release agent onto the skin to prevent the plaster sticking on skin or hairs. Even though it's messy petroleum jelly is the best to use. Even if hairs get caught in the dry plaster they can slip out without too much agony.
As can be seen in the photo it *is* agonising removing a plaster mould if you forget this step. -
Step 2
Get a roll of plaster bandage, dip it in a bowl of water and start laying it on the foot, fold on fold. Rub the bandage to make the plaster soften and mix through the bandage. As the layer gets thicker keep kneading the bandage down and around the foot to ensure the plaster and the bandage get into all the crevices. Repeat this until the plaster and bandage are about half an inch thick. Keep smoothing it with your hands until you feel it getting warm and hardening.
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Step 3
Take extreme care not to plaster all around the foot otherwise you will not be able to remove the mould. After it has hardened sufficiently carefully pull the mould from the foot while it is still a little flexible. Feet are a bit soft and flexible as well so you shouldn't have a problem.
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Step 4
The mould is ready for making casts. Plaster bandage is a super quick way of making a mould where you don't need a lot of definition. It also makes a good support jacket for alginate moulds of the face for example. Dental alginate sets quickly (minutes) and captures very fine detail. They are also very weak and need a support jacket. Plaster bandage is ideal because it can be applied directly, sets quickly and has no harmful solvents.
