Using spray foam to create a volcano will make the project much quicker and less messy than using other methods. Making a volcano from spray foam will also make the volcano light weight and easy to carry, which is a plus if a child will have to carry the project to school. Spray foam can be purchased online or at any home improvement store. To make the foam volcano eruption more dramatic, add a couple drops of food colouring to the volcano mixture.
Place the empty 2 litre pop bottle in the centre of a 1/2-inch-thick plywood square piece, cut to 12 by 12 for the base.
Spray the foam insulation, starting at the bottom of the pop bottle. Be sure to seal the pop bottle to the plywood when spraying on the first coil of foam around the bottom of the bottle. Layer the coils of foam spray on top of the previous one until you get to the top of the bottle. Do not cover the top of the pop bottle. Allow the volcano to dry.
Spray the volcano with spray paint in the colour of your choice. Allow the paint to dry.
Add 1/2 cup of hydrogen peroxide to the pop bottle using a funnel.
Put 2 drops of dish soap into the pop bottle.
Add 1 tsp of yeast to 1/2 cup of warm water to dissolve the yeast.
Pour the yeast mixture into the pop bottle with the funnel to make the volcano erupt.
Use two to three colours of spray paint to make the volcano look more realistic. Keep the pop bottle lid to make the project easy to carry without spilling anything.
Spray paints should only be used in well-ventilated areas. Wear gloves and a dust mask when working with spray foam and spray paints.