What should be done to prevent the wax from cracking during the cooling process?

The beeswax, of course, should be thoroughly clean and clear. This is accomplished by melting choice capping wax in soft water with gentle boiling and careful straining of the wax until you have a clean and clear liquid. The wax should be approximately 175 degrees F. when you cast the cake. The container in which you cast the cake should have a smooth flaring side and should be heated to about the same temperature as the beeswax prior to casting the cake. This container should be placed in an insulated box preferably not much larger than the container and with a cover for the container. Carefully pour the liquid wax into the center of the container being sure not to splash any on the edges or sides of the container and then place the cover on the container so that the wax and container can cool very slowly, taking hours to do so.

Another way is to place the container in a pan surrounded by hot water, pour the cake, and then cover the container, allowing the wax to cool and congeal slowly. Do not remove from the mold until fairly cooled.