Pour 6 cups of water into a large bucket. Put on a dust filter face mask.
Pour 5 lbs. of hydrated lime into the bucket. Many gardening supply stores sell hydrated lime in bags as small as 5 lbs. and sacks as large as 100 lbs..
Pour 12.5 lbs. of coarse sand into the bucket. Chuck a paint mixer attachment into an electric drill.
Mix the plaster with the paint mixer attachment for about three minutes before you start to sprinkle animal hair into the mix. Animal hair is a traditional ingredient in lime plaster although some plaster masons report success with other fibers, including cellulose, when plastering straw bale homes.
Continue to mix the plaster and add animal hair until the plaster mix incorporates 8 oz. of hair.
Apply the plaster using common plastering methods holding a trowel at a 75 degree angle. Lime plaster sets more slowly than gypsum plaster.