Abstract
M.Tech. (Ceramics)
The research project attempts to fill a void by assembling data dealing with a comprehensive range of South African clay and glaze materials, suited to the needs of the studio potter, and recording test results.
South African kaolins, ball clays, fireclays, miscellaneous clays, grogs, bentonites, felspathic materials, alkaline earths, silica, refractory materials (other than clays) and
mineral pigments are dealt with. A limited selection of foreign materials, frequently referred to in studio-potter publications, was also used in comparative tests. The materials are recorded with reference to the ultimate analysis, seger formula, proximate analysis (where applicable), properties and results of trials using the materials in clay bodies and/or glazes.
It was demonstrated that South African materials are largely of good quality e.g. kaolin, felspars and silica. Variability of clay supplies because of lack of stockpiling and blending practices, especially by small suppliers, is often a problem.
When the composition of glaze materials and trials indicated that imported equivalents were superior because of variability of local supplies or poor grade material, then substitutes were tested using South African materials.
Basic clay bodies and glazes covering a wide temperature range from Egyptian Paste, low-fired wares such as raku, terracotta-and-white-earthenwares, stoneware and soft-porcelain bodies and glazes are dealt with giving a brief outline of the requirements for each type. Suggestions of suitable South African materials for their composition are made. Trials and results are recorded.
The knowledge gained of South African materials available and a study of the materials enables the studio potter to utilize local materials with awareness and confidence