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.