This paper deals with the topic of improving a value adding chain for inorganic bonded cores used for manufacturing of lightmetal gravity castings. Describing the state of art in that field the investigation focusses on the main issues of inorganic coremaking when using a system based on magnesium sulphate and water. These issues occur during storage and transportation as well as during dehydratization inside or outside the core box. Basic investigations were conducted to clear the effects of air humidity and temperature on manufactured cores. From those results regulations and process parameters can be derived to secure safe core transportation and storage operations. To ensure moist free cores and to gain an easy-to-measure parameter during production a new process of drying and hardening of inorganic bonded cores will be developed and investigated in this paper. In this process vacuum technology is used to dry out water from the core while using partial pressure as a parameter for process control and operation. A further development of this process should be possible by using a pilot installation, which can be dimensionized by using the results of this work.