Plaster is a porous building material that can be used for a multitude of indoor craft projects, including making decorative plaques and hanging garden stones. The inexpensiveness and malleability of plaster make it suitable for use as a mold for other materials, such as clay, craft dough and concrete. However, the primary ingredient in plaster powder, gypsum rock, is highly malleable and may be dissolved through exposure to wind, heat and rain. For this reason, plaster is not suitable for outdoor construction projects. Your stones would crack or develop mold if used to create a functional pathway. Instead, use plaster to create a purely decorative garden stone.
Cover your workspace with newspaper or a plastic tarp.
Pour the 1 cup of water into the bowl.
Add 2 cups plaster.
Let the plaster absorb the water for 30 to 60 seconds.
Stir the mixture slowly to incorporate the undissolved plaster. Do not lift the stirrer from the bowl, as this will create air bubbles.
Add more plaster or water as needed until the mixture reaches a smooth consistency similar to pancake batter.
Tap the bottom of the bowl from the outside to release any trapped air. Continue tapping until air bubbles stop breaking the surface of the plaster.
Add two to three layers of wire mesh or fabric, such as cotton or denim, to the middle of your mold as you pour the plaster. Do not use a coated fabric as the plaster must penetrate the material.
Add glitter or fine craft sand to texture and decorate your plaster.