One example of a naturally formed fossil mold.
Paleontology is the study of fossils, dinosaurs and in general the remains of extinct animals. The fossils they find are rare and as such can be valuable tools for research into life on Earth in the time of the dinosaurs. For much of the research, scientists prefer to use casts of the fossil rather than the actual fossil to prevent damaging the rare find. Making a mold and cast of a fossil can be a great lesson for middle and high school science students.
Instructions
Mold Fossil
1. Spray the inside of the pan generously with non-stick spray. Fill the pan halfway with soft clay. A mold fossil is the type that would be created by a scientist out of an original fossil. If the fossil is extremely fragile, there are better methods to use including three-dimensional computer imaging.
2. Spray the bone, leaf or shell with non-stick spray and press into the clay surface in the pan. Spray the top layer of clay with the non-stick spray.
3. Place one strip of cardboard at the top of the clay surface in the pan and another at the bottom. The bone and cardboard should not touch. Smooth another layer of clay on top of the bone and cardboard strips. Allow a few hours for the clay to dry.
4. Remove the clay from the greased pan and then separate the two halves at the cardboard seam. You now have a temporary mold.
5. Use plaster to create a more permanent mold using the same steps as for clay. The only exception is that the plaster must dry completely before attempting to separate layers. This may take up to 48 hours for a solid mold.
6. Pull the two halves of plaster apart gently beginning at the seam created by the cardboard strips. If the seams are stuck, use a butter knife or dull pry tool to get them apart.
Cast Fossil
7. Lay the mold fossil halves flat side down on the work table. A cast fossil is created when the original leaf, shell or bone has been buried creating the impression of its shape. The original fossil is washed away or dissolved through by natural processes leaving only the hardened impression.
8. Fill the mold with liquid latex on both sides, the level of latex should be flush with the top portion of the mold and not "bubble over" the lip of the mold.
9. Allow 48 hours for the latex to dry completely and remove it from the plaster mold. For a three-dimensional representation of the fossil, glue the two half pieces of latex together.
Tags: non-stick spray, with non-stick, with non-stick spray, Allow hours, bone cardboard, cardboard strips
