How to Make Rock Molds
- 1). Cover the rock you are using for your mold with six coats of the silicone or latex rubber mold. Allow the latex to dry fully between each coat.
- 2). Put a layer of gauze or cheesecloth over the rock before applying the seventh coat to strengthen the mold. The mold should completely cover the top and sides of the rock you are using; leave the bottom open so you can remove the mold.
- 3). Apply the seventh layer of mold.
- 4). Let the mold set for 24 hours after applying the seventh layer. Carefully peel back the mold from the original rock.
- 5). Mix the plaster of paris until it is the consistency of pancake batter. Place your mold in the sand; this will keep it from bending when you fill it.
- 6). Fill the mold with plaster of paris and allow it to sit until it has dried completely, which will take from 45 minutes to an hour.
- 7). Carefully remove the plaster from the mold before painting or displaying it.
- 8). Paint the plaster rock using a durable, waterproof paint, especially if it will be used outdoors.
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