The thermal dynamics of the sprue system is an area of major importance that is often neglected by jewelry casters. The influence of specific alloys on how well the sprue system works is likewise often overlooked, as demonstrated by our one-size-fits-all approach to feed sprue design. Feed sprue design that decreases the temperature loss of metal as it travels through the sprue system to the pattern are discussed. It is shown that industrial casting practice can be instructively applied to jewelry casting. We can understand the use of a riser and see how the main sprue serves that purpose in most jewelry casting. The function of the sprue button is questioned and buttonless casting is discussed for production and one-of-a-kind casting. Finally, it is shown that using a riser makes it possible to produce sound heavy-section casting in pure silver and pure gold.

Author: Eddie Bell