Relating Soil Moisture Content to Adhesive and Visual Characteristics of Clay for Painting and Three-Dimensional Artwork

Abstract

The research work explicated moisture variation in clay soil as it affects its adhesive and visual colour characterization for painting and three-dimensional artwork. It involved subjecting clayey soil to particle size analysis thereby obtaining the actual clay soil content. The clay was taken to laboratory, conditioned and determined its moisture content variations at every time interval until no visual variation was observed. A mixture Gmelina (Gmelina arborea) seed extract and Teak (Tectona grandis) leaves extract was used as solvent to make a paint solution with the clay sample at each observed time interval at ratio 1:5 (clay to solvent) by weight. It was discovered that as the cumulative moisture variation increases, instant moisture variation decreases until a constant value in every measurement was obtained. Colour variation in the clay under observation was also noticed to have stopped when other measurements attained their constant values of 0% and 5.7% for moisture variation and cumulative moisture variation respectively. In the same vein, adhesion test was conducted using cross-cut test procedure. The study showed that the actual colour of any three-dimensional artwork and painting done out of clay could only be precise until all forms of water other than hygroscopic water are fully dissipated and this is achievable after 10^th hour of drying process at temperature of 105 ⁰C. A stable moisture variation was attained at moisture content of 23% moisture loss and 10^th hr of the drying process. Evaluation of colour uniformity showed that the optimum moisture content for a uniform colour in clay soil is obtainable at 25%. In addition, adhesion strength (based on ISO/IJS classification) of clay was carried out at every drying time interval. Adhesive test was carried out on the coated surface using QFH Cross Cutter Adhesion Tester at 2 mm gauge showed that 0-5hr drying time (6-17.6% mc) gave high adhesive score of 5 (poor adhesion) while 8hr and above drying time (23% mc) gave a lower score of 2 (high adhesion) which suggested better resistance to environmental stresses. The result showed that clay has better resistance to abrasion as it gets dryer.