fusing into small molds
I was at Bullseye Glass in Portland and we made one larger open face mold for casting glass. In order to find out the volume of glass needed for the mold. The instructor had a measuring cup filled with water, then filled the mold to top with water. The amount of the water remaining in the cup was noted and the difference was the amount in the mold. This gave us the volume of the mold. Then we weighed the amount of glass needed to fill this mold. We used billet solid glass chunks and they extended above the surface of the mold.
I will use this method to find the mold volumes for these small molds. I think I will try small pieces or chunks of glass to see how that works out.