Description
Abstract
This project is centered on the development of colored Engobe compositions for local structural clay products. Engobe, slip, glaze and terra sigillata are all used for decorating ceramic pieces. The raw materials used for this project are Nsu clay (calcined and uncalcined Nsu clay), talc, feldspar, quart and colorant. The uncalcined clay in the composition was used as a hardener, this tends to recrystalize in the Engobe when it dries on the ware and this forms a tougher harder coating which is less prone to damage during handling. The talc in the compositions was used as a flux. After application on a local structural clay product (tiles). The sample were fired at the temperature of 950–11000C for test one and 11000C for test two and 12500C for the test three. It was ensured that the Engobe matured at the same time with the substrate (tile). The linear expancivity of the Engobe was also considered during the formulation. Finally, metal oxides were used up to 5% in the Engobe composition to give different colors to the tiles.
Deon –