With the variety of castings that are produced today, it is common for the manufacturing process to be modified to accommodate complex designs. Given the myriad of process variables, a good understanding of the impact these changes may have is important. In the investing area, there are a number of process factors. One of these is the water-to-investment powder ratio. Water-to-powder ratios are, at times, changed by the user for a number of reasons, such as increasing mold strength or changing fluidity. It is important to ask if changing the water-to-powder ratio is significant. Jewelry investments are designed to be used in a narrow range of water-to-powder ratios. Using water-to-powder ratios outside the designed range may adversely affect other characteristics as well as lead to potential casting defects. This paper will explore how investment properties change as a function of the water-to-powder ratio and how these changes can affect mold and casting attributes.

Author: Ralph Carter