30/07/2026
Shells have been used in wood firings in Japan, since the Edo period (1600-1800) and have been used in the west since anagama kilns were introduced. Svend Bayer was one of the first potters to build an anagama kiln in the United States in the early 70s after his time studying the design of traditional wood fired kilns in Korea, Japan and Southeast Asia, and was subsequently the first to build one in England
Shells are valued both practically, as they can be used to support the pot and aesthetically for the rather beautiful halo marks they leave on the pot caused by the interaction of calcium and silica.
Here in Gower I have plentiful access to cockle shells, as cockle harvesting dates back to Roman times and continues to this day. The shells are not as thick as oyster shells but they work well going up to 1300c in my firings. The calcium from the shell reacts with the silica and alumina in the clay and a part of the shell fuses with the surface of the pot. After the firing, the part of the shell that isn't fused to the surface of the pot will disintegrate after absorbing moisture from the air.
•
•
•
