When you are constructing a volcano for a class project or for a science fair exhibit, you may think of using a flour dough mixture for the base of the volcano mountains. However, flour dough can often crack and split when it dries, leaving your mountains less likely to erupt properly. One solution is to make the mountains out of clay, which will provide the project with a stable base that will remain intact throughout the experiment.
Roll out 227gr. of terra cotta clay into a sheet that is 1/4 inch thick. Place a paper towel tube onto the centre of the clay sheet, and wrap the sheet up around the paper towel tube. Trim off any excess clay that is sticking up over the tube. The bottom of the tube should be covered. Allow the clay to dry for 4 hours, which will make the clay firm but still containing moisture. Remove the paper tube from the clay form.
Crumple up six to eight sheets of newspaper into a mountain, and tape the papers together with masking tape to secure the form in place. Roll out 0.907kg. of terra cotta clay into a sheet that is 1/2 inch thick, and drape the clay sheet over the paper form.
Cut a 2-inch hole out of the top of the mountain. Allow the clay to dry for 4 hours so that it is firm yet still containing moisture. Remove the newspaper from the inside of the mountain form.
Slide the clay tube into the centre of the mountain form. Roll out 227gr. of terra cotta clay into a coil that is 1/2 inch thick, and wrap the coil around the seam where the clay tube meets the hole in the mountain. Allow the mountain form to dry for 8 hours.
Paint the outside of the clay mountain with ceramics glaze. Select colours that will resemble a real mountain, such as tan, brown, green or white. Allow the glaze to dry for 2 hours.
Fire the mountain in a kiln set to medium-high for 3 hours. Allow the mountain to cool for 6 hours before handling it and using it in your volcano experiment.
Fire the clay mountain in a kiln under the supervision of a professional ceramic artist. Kilns can be extremely hot and can cause severe burns if touched during the firing process.