Clay is granite rock ground into crystalline particles that are composed of silica, alumina, sand and even glass. Cast ceramics are made by mixing clay, water and chemicals together, creating a cream-like liquid called slip. Slip is then poured into hollow-shaped molds made from plaster of paris. The mold absorbs the water from the slip, leaving a solid layer of clay near the porous mold. Excess slip is drained to be reused, the mold is removed and the formed piece is now called greenware. Fresh greenware must dry and harden for 24 hours, after which time it is still very soft and can be molded and shaped slightly. Greenware is cleaned, painted, fired in a kiln and then ready to be used as a planter in the garden. No matter how carefully greenware is handled, items can break on occasion.
Apply Elmer's glue. Squeeze a moderate amount of glue on each piece to be glued back together. Avoid using excessive amounts of glue.
Press the two pieces of greenware together. Wiggle them gently back and forth until the pieces are nestled together snugly.
Remove excess glue by wetting a sponge and squeezing off excess water. Wipe off any residual glue from the greenware pieces, taking care not to shift the pieces in the process.
Fill any crevices or gaps with Elmer's wood filler. Apply a small amount to a putty knife and spread over any spaces or holes around the break. This process also helps fortify the glue.
Apply a thin layer of Clearcote acrylic sealer with a paintbrush to protect the repair.