How can I make my clay model waterproof?
Clays are materials that are molded to form beautiful and hardened shapes. They are an upcoming hobby and widely used in pottery and shaping crockery.
To make clay waterproof, it needs to be waterproof. If it is polymer clay then bake it in an oven and by turning it into ceramic clay, fire it in a kiln which will give you a total waterproof clay.
Simply put clay can be made waterproof by either taking earthen clay and then firing it in a kiln at high temperature or use polymer clay that can be baked in a home oven to PVC plastic.