Clay - I use a stoneware clay from St Amand en Puisaye a village close to La Borne, in France. This clay has traditionally been used to produce wood fired salt glaze pots, tiles and bricks. The combination of flame, ash deposits and salt vapour passing through the kiln fires the clay subtle shades of light grey through to dark brown. Click here to buy some clay.
Slips - Different colours and textures are determined at the slipping stage. Slips are applied when the pots are leather hard. Slips are a mixture of unfired clays, minerals and water, sometimes with oxides added. Most of the reds and oranges are made from mixtures of china clay and ball clays. Oxides are added to produce colours like greens and blues.
Making - I was a student of 'Studio Pottery' at Harrow College of Art where I learnt production throwing and gained my experience in all aspects of running a studio pottery; making a kick wheel, my own tools, mixing clay and building and firing a wood salt kiln. I use a kick wheel which determines a slow rhythmical throwing pace and an electric wheel for larger pots. Over the years my approach to potting has changed and developed. I now make pots in small series, creating the same form in various sizes and exploring the relationships between them.
Kiln - I built designed and built my present kiln in the spring of 2001 with the help of Kirke Martin from the USA and Annett Krage Nielson from Denmark.
The firing - The kiln is wood fired and takes about 30 hours to reach a maximum temperature of 1320°C. It has a strong cross-draught, drawing the flames right through the kiln and depositing wood ash on exposed areas of the work. Most of the stoking is done through the firebox but at certain points in the firing, wood is also side-stoked into the main chamber, enabling more control of atmosphere and temperature.
Salt and ash - The texture and colour of the pots is created by the deposits of ash and salt melting on the surface of the clay. The wood ash combines with the sodium in the main chamber to produce a wood-ash and salted glaze surface. The unpredictability of firing with wood and salt ensures that every pot that emerges unscathed from the firing is different.
Atmospheres - The kiln isdesigned to allow the exploration of different atmospheres in the same firing. Alongside the main chamber, the oversized firebox is capable of holding pots. The pots in the firebox are kept separate from the salt vapours and are glazed only by the wood ash. This allows us to explore different aesthetics in the one firing. The smaller back chamber, between the main chamber and the chimney, acts as a small firing chamber as well as a collection chamber.
Kiln dimensions - Packing Space; Front chamber : 0.5 cubic metres, 17.5 cu.ft. Main Chamber : 1.75 cubic metres, 62.0 cu.ft. Back Chamber : 0.5 cubic metres, 17.5 cu.ft.
Rhineland - Salt glaze is an exclusively European tradition and developed in the Rhineland of Germany. It is not clear how the process of salt glazing emerged. One theory is that it was discovered during the 14th century by potters stoking their kilns with boards from barrels that had previously been used to transport salted herring. Early on, earthenware slips were used to produce pots with a rich chestnut hue. Later, a cobalt blue wash was applied to the grey body. This tradition continues to this day in Hohr Grenzhausen, Germany.
Staffordshire - During the 17th century a more refined white salt glazed ware was developed in Staffordshire in England. During the 18th and 19th centuries a rich brown salt glaze was produced and much utilitarian ware was glazed in this way. During the early part of the 20th century salt glaze was used to create highly decorative pieces. However, by the middle of the last century its use in Britain was confined to the production of sanitary ware, chimney pots and sinks.
La Borne - Salt glaze pots were made in France from the mid 18th century and continue to be made in La Borne. The traditional production potteries no longer exist, but a strong community of individual potters is still working there.
North Carolina - The knowledge of salt glaze was taken to North America in 1700s and vast amounts of salt glazed pots were made throughout the North East of the United States between the late 18th and early 19th centuries. Today, the tradition continues in North Carolina. Interest in salt glaze was encouraged in Alfred University in the 1950s and there are many studio potters exploring this medium across the US today.
Britain The use of salt glaze in British studio ceramics began tentatively with the work of the Martin Brothers in London. Bernard Leach and Hamada experimented with salt glaze. However it was really the pioneering work of Denise and Henry Wren that became the basis of the experimentation with salt glaze that took place in the early 70s at Harrow School of Art. I was lucky enough to be on the Studio Pottery Course at Harrow during this intensely creative period.