casting a 3D printed hand

Alissa has been working on getting a 3D printed hand ready to cast in metal. She sprued the the prints  and prepared the small holes in the fingers by adding graphite lead into the small holes. This will assure that the holes stay clear of molten metal and that they don't get filled in. The granite extends out past the part so that it get imbedded in the investment. The graphite acts a "core". After she completing the sprues, which will act as smooth passage ways for the metal to enter into the mold, she weighs the models. The measurement will allow us to estimate the amount of metal that we need to melt for each mold, which is dependent on the specific gravity of the metal we use. She mixed a plaster investment that we use for making the molds. The liquid investment will flow in and around all of the parts. Bubbles are removed by vacuum or by wrapping the side of the flask with a spoon or butter knife. After the investment has solidified, we will remove the rubber flask bases and then we can place the molds in a burn out kiln. The investment can withstand hight melting temperatures and the wax sprues and 3D print will melt out, leaving us with clean empty cavity/mold in which metal can be poured into. More on that soon...