Things You'll Need
- Styrofoam
- Construction glue
- Rasps
- Knives
- Non-sanded grout
- Water
- Mixing bowl
- Cheap paint brushes
- Acrylic paint
- Non-toxic sealant
Instructions
Glue several pieces of Styrofoam together, using construction glue, into a form that is slightly smaller than you want for your finished rock. Allow the glue to dry overnight.
Shape the Styrofoam rock as needed with rasps and small knives until you reach the desired shape.
Mix a small batch of non-sanded grout with water, following the manufacturer's instructions.
Brush a thin coat of grout over the entire rock form with a cheap paint brush. Allow the grout to dry.
Apply three additional coats of grout onto the rock form, allowing each to dry before adding the next.
Paint the dried rock with acrylic paint. Look to real rocks for color patterns. In general, you should have three colors: a base tone with a highlight and shadow.
Seal the rock with three layers of non-toxic, brush-on sealant. Allow each layer to dry before adding the next.
Allow the rock to sit for three weeks before adding it to a reptile cage. This will allow all fumes from the sealant to dissipate.