David Voorhees is a professional potter from North Carolina who works with porcelain. He presents an online workshop at TeachinArt online school of art and demonstrates in the e-course how to do spiral wedging.
For those of you who do not know what wedging is in clay terms, it is to remove all air bubbles or air pockets from the clay. Any air trapped in the clay, makes the centering of the clay on a potters wheel so much more difficult and if an air pocket is trapped inside clay and you fire it in the kiln, it can explode. Wedging helps to spread moisture evenly throughout the clay which helps with easier centering on the wheel. Even if you do not use a potter's wheel and only work with hand building, then wedging is just as important. Many potters have experienced the shock when they opened the electric kiln and see that one of their pots (with air trapped air inside) exploded and messed up all the surrounding pots.
The spiral wedging technique is handy when you have to wedge or knead large clay batches. It is also called the Japanese wedging or kneading. Some potters only use the spiral method. We will post later other wedging techniques.
For more information about David's online workshop or e-course click here to see the contents of the class and to register (Porcelain tips for wheel pottery)