This study shows the results of the investigation of the strength performance, and residual strength of a single component inorganic binder

system Cast Clean S27®. The study was conducted using three different foundry sand sources in South Africa. Sample A is an alluvial

coastal sample, sample B is an alluvial riverbed sample and Sample C is a blasted sample from a consolidated quartzite rock. The binder

was also cured using three different curing mechanisms. The aim of the investigation was to determine the variation of strength

performance and residual strength between the different South African sand sources based upon the physical and chemical properties of

the sand sources. The moulding sand was prepared using three possible curing mechanisms which are carbon dioxide curing, ester curing

and heat curing. The strength measurements were determined by bending strength. Sample A and sample C sand had good strength

development. Sample B sand had inferior strength development and excellent high temperature residual strength. The study showed that

the single component inorganic binders have good strength development and low residual strength. The silica sand properties have major

contributing factors on both strength development and residual strength. The degree of influence of silica sand properties on strength

performance and residual strength is dependent on the time of curing and method of curing.