How to Repair Cracked Stoneware. Stoneware can be a great investment or used simply as decoration around the house. When a crack appears, you can throw the piece away. But if you want to keep that piece of stoneware, you can repair the crack by following these steps.
Clean the stoneware pot thoroughly, being careful not to extend the crack. Dry it completely so the repair will stick.
Open the crack very slightly more with a thin utensil with a flat edge, being careful not to pry it all the way open. Apply a thin layer of waterproof silicone caulk or polyvinyl acetate (PVA) adhesive to each side of the crack.
Apply enough pressure to stick the two sides together while being careful not to push too hard. Hold together for about one minute.
Wipe away any excess sealant using the utensil you used to pry the crack apart. Take the flat part of that utensil and gently scrape away the portions that are not inside the crack so the appearance of the stoneware is still smooth.
Let dry for at least 24 hours. Test the crack carefully before using the stoneware, and follow the steps again if it's not completely repaired.