Lightly sand the terracotta flower pots and saucers, eliminating any rough spots.
Place the 20-inch saucer upside down on a level surface. Put the first terracotta flower pot upside down on the center of the saucer bottom. Trace the rim of the flower pot onto the saucer bottom with a pencil.
Place the 24-inch saucer upside down on a level surface. Put the second terracotta flower pot upside down on the center of the saucer bottom. Trace the rim of the flower pot onto the saucer bottom with a pencil.
Apply contact cement on the rim of the first flower pot and just inside the drawn circle on the bottom of the 20-inch saucer. Press the two glue-covered surfaces together. Let them dry completely.
Apply contact cement on the rim of the second flower pot and just inside the drawn circle on the bottom of the 24-inch saucer. Press the two glue-covered surfaces together, and let them dry completely.
Apply contact cement on the bottoms of the two remaining terracotta flowerpots and on the bottoms of the two flowerpots that are now attached to the saucers.
Press the bottom of one loose flowerpot firmly onto the bottom of each flowerpot attached to a saucer. Allow these to dry completely.
Apply contact cement to the rims of the two terracotta flowerpots that are now facing up on each saucer. Press these rims firmly together. Allow to dry. The 20-inch saucer is the stand, or bottom, of the birdfeeder. The 24-inch saucer is the bowl for water.
The terracotta birdbath can be painted in any design you like. Use waterproof, durable or weather-resistant paints.
Paint on a clear, water-based sealant after painting the desired designs on the birdbath to protect your artwork. Apply two to three coats for a weatherproof seal, drying thoroughly between each coat.
Place your terracotta birdbath in your garden, fill it with a few inches of water, and watch the birds enjoy your efforts.