The following is an overview of my process from Wood Storage to Firing to Showroom.
For more details about specific elements, you may wish to look at Making Clay, The Wood Kiln, and Glazes.
Wood storage
The wood for firing is stored for 2 years so that it is as dry as possible before it is used in the kiln. The wood is cut from an adjoining forest into 1 metre lengths diameter less than 20 centimeters. The bundles shown here have been made by stacking the wood in a cradle then wiring them. They are then able to be lifted by a small front end loader and dropped close to the kiln firebox.
A firing will require up to fifteen of these bundles to get to temperature and hold it there for a soaking period of two or three hours. That is about two to three tonnes of wood….
The firewood forest
These pines were planted in 1980 at 1 metre spacings in rows about 1½ metres apart. This tight planting has forced the trees to grow tall and thin – perfect for chopping into metre lengths for the kiln’s firebox. The firebox can take wood up to about 20 cms diameter. Most of the plantation trees are under that diameter and up to 35 metres in length.
Bisque storage area
This photo shows the Bisque storage area and the bisque kiln (left) in the process of unloading.
The racks on the right (background are full of pots that have been fired for the first time. After the pots have been made on the wheel they are dried to leather hard then finished by being turned and handled if necessary.
The next step is to dry them completely before they are bisque fired. If they are not totally dry they can blow up as any remaining water turns to gas as steam.
This first firing also drives off the water which is chemically combined in the clay and turns it into ‘brick’. This means that the pot can be dipped into the glaze (which is a suspension in water) without dissolving and disintegrating.
As can be seen here the pots are stacked in the kiln one on top of the other. In the second firing when the pots are glazed each pot must be separated from all others so that the glaze doesn’t melt them together.
Glazing area
Stoneware glazes are made of very common rock materials similar to those that form the clay body. The addition of fluxes like limestone makes these materials – silica, clay and feldspar – melt, as a thin glass layer on top of the clay.
These pots are bisque fired and ready to be dipped in the creamy glaze mixture. They will then be placed on shelves in the kiln ready to be fired for the second time to 1300 centigrade.