A model of a volcano makes an eye-catching and impressive feature for a science fair or geography class project. Papier-mache you make with PVA glue will form a sturdy shape for you to decorate. Papier-mache is versatile enough to allow you to create volcanoes of many different sizes and shapes using the same basic method. No two papier-mache volcanoes need be the same. Allow several days for the project because the model will require a lot of drying time.
Cut a circle or square shape approximately 20 inches across from the side of a cardboard box for the ground around the base of your volcano. Lay it on a flat surface.
Inflate and tie a balloon and tape it to the centre of the cardboard base with the round end at the bottom. Do not worry if it looks messy at this point as you will cover it with papier-mache soon.
Pour two parts PVA glue and one part water into a bowl and mix thoroughly. Rip newspaper into strips.
Dip a strip of newspaper into the glue/water mix and drape it over the bottom of the balloon and onto the cardboard base. Work around the rest of the balloon like this. Continue adding more strips up toward the top of the balloon and over the base. Build these up to create a conical vocano shape that joins smoothly with the ground beneath. Leave an area at the top of the balloon free from paper strips. This will be the crater.
Add three more layers of papier-mache over the entire surface and leave the model to dry overnight. The next day, add three to four more layers of papier-mache. Press more strips on some areas than others to create an uneven rocky effect. Leave the model to dry again overnight.
Pop the balloon inside the model if it has not already deflated.
Mix black and white paint together on a palette to create a grey undercoat and paint over the surface of the volcano. Paint the base around it green. Leave the volcano to dry, then varnish it with a final layer of clear plastic glue. Scrunch up orange tissue paper and stuff it inside the hole you left at the top of the crater to make the lava inside your volcano.