How to Pour a Plaster Mold for Ceramics

Using a slip-casting mold is one of the most efficient ways to create beautiful, detailed ceramics. As with anything, there is an art to pouring ceramic slip into a mold, though the process is relatively straightforward and easy to master with a little practice.

Things You'll Need

• Ceramic slip-casting mold
• Soft brush
• Rubber bands or mold strap
• Ceramic slip (liquid clay)
• Plastic stirring object
• Pouring table or large bucket/container
• Small cutting tool

Instructions

1. Open the ceramic slip-casting mold and clean it with a soft brush to remove any dust.

2. Close the mold tightly and fasten it with rubber bands or a mold strap.

3. Set the mold upright so that the pour hole is on top.

4. Stir the ceramic slip well, and then slowly pour it into the mold, making sure no air bubbles are present. If you see air bubbles, gently jostle the mold to pop them.

5. Add slip to the mold every few minutes, as the plaster in the mold will absorb the water in the slip.

6. When the slip thickens to approximately the width of a nickel — thickness varies based on the size of the item — pour the remainder of the slip slowly out of the mold into a bucket or pouring table.

7. Leave the ceramic item in the mold until you feel that the mold will open easily without separating the piece. The amount of time this will take will depend on the size of the piece, but the piece should at least have the firmness of leather.

8. Open the mold carefully. Set the object in a safe place and allow it to dry overnight. If you need to trim or smooth any edges, do so before setting the piece aside to dry.

References

• "Ceramics: Mastering the Craft"; Richard Zakin