Improved Core Composition for Traditional Lost Wax Casting at Krofofrom, Ghana

Abstract

The composition of casting mould cores used by Krofofrom artisans comprises charcoal, cow dung and clay. Although this composition results in a very stable core that disintegrates easily after casting, defects in the form of pin holes are a common occurrence on the inner walls of the cast artefacts, thereby ruining the finish. In many instances these pinholes are difficult if not impossible to remove or seal. To improve the performance of the existing core, experiments were carried out to determine suitable materials and the proportions required to reformulate and enhance the core composition. The addition of Plaster of Paris (P.O.P) to the composition prevented shrinkage and fracture while the presence of saw dust provided microscopic holes in the core structure to facilitate easy core disintegration after casting. High content aluminous clay component served to improve the refractory properties of the core. The new core composition comprising charcoal, P.O.P, saw dust and aluminous clay showed an improvement over the existing Krofofrom core composition. The improved composition yielded efficient cores that disintegrated easily after casting and impart smoother inner wall surface devoid of pinholes.