Lime plaster is an old technique used in buildings before cement was used. It's coming back into popularity because it's more ecologically friendly than cement. If you're thinking of working with lime plaster, you need to know how to make it. Lime plaster does take some time and effort to create properly.
Make safety a priority. Lime plaster can be volatile. Wear a mask, goggles and gloves when working with lime plaster.
Pour water into a metal bath. If you're only making a little lime plaster, a wheelbarrow may work. Since you can generate heat when making lime plaster, make sure the bath isn't on dry grass or paper or you could have a fire.
Add quicklime to the water, slowly, making sure to mix it as you add it. You can mix the plaster with a garden hoe. It may be easier to use two people, one adding the quicklime, the other mixing. Continue mixing until all the lumps are gone.
Run the mixture through a fine mesh screen to remove any chunks of limestone. Large chunks of limestone won't react with the water.
Store for 3 months before using. Store the lime plaster in a sealed container to prevent air from reacting with it.
Expect this process to take you a few hours, depending on how much lime plaster you're making.
Never add water to pure quicklime or it could explode.