A practical method to determine meaningful permeability values for ceramic shell moulds used in the bronze casting process

Abstract

This paper proposes a pragmatic means to evaluate the degree of permeability of different ceramic shell moulds using a low cost practical method as compared to a more sophisticated hot permeability method. The proposed method makes use of a blind riser as a "barometer" strategically attached to a mould to measure the different heights attained by molten bronze when poured into the mould in question. By arithmetic calculation the height of the bronze column in the blind riser gives an indication of the permeability of the ceramic shell mould under investigation. The permeability values thus obtained could be useful as an indicator to determine the number of risers that will provide sufficient air-vents for the moulds during a bronze pour.