I found an article on the internet regarding how to sand cast 3D Printed Objects. Here are the simple steps:
1. 3D print plastic model.
2. Make a sand mold with your 3D print (Basic flat surface)
3. Casting complicated 3D prints (bake method)
– Fill empty two part mold 1/3 full of sand. (make sure flat or bottom of piece is facing up)
– Place the piece you are casting in the mold (centered) w/ bottom facing up and pack sand around it as you go.
-Once the mold is in place, turn it gently upside down and place in a drip pan in your oven at 400 degrees to allow the plastic to melt out into the pan (takes up to 4-6hrs based on size of mold).
– Once the plastic is melted out, take the top of the 2-part mold, fill it with sand, and poke a hole at the base of your piece. This gives you a channel to pour metal into.
4. Ignite the Kiln
5. Place metal stock in kiln to melt
6. Pour your metal into your mold(s)
7. Allow metal to cool (generally takes 5-30 minutes).
8. Break apart the molds(s).
9. Quench your cast piece in water or oil depending on the metal used (oil for higher carbon metal).
10. Finish cast piece with desired finish (oil, wax, paint, gold leaf, etc…….)