How to build a model volcano

Last year, for geography, I made and erupted a model volcano. I posted the result on youtube and to date it’s had over 60,000 views – not bad for a geography project! I’ve had lots of requests for instructions, so I’ve decided to explain once and for all how to make a volcano you can erupt in the back garden.

You will need:

• Polystyrene tray or something similar
• Pipe/tubing
• Pot
• A length of hose or piping
• Duct tape
• Newspaper
• Tape
• Papier mache (or oodles of PVA glue)

1. Cut a hole in the polystyrene tray so that you can fit your tubing through. I used a white plastic piece about 2″ in diameter that wais meant for plumbing. This will be the centre of your volcano.
2. Take your plastic pot (I used one that’s meant for washing liquid) and attatch it to the bottom of the tubing. Use the tape to secure the join so that it’s watertight. Doesn’t matter if it isn’t perfect.
3. Hack a hole in the side of the pot so that you can stick the hose in. Once again, use tape to secure the join.
4. Stick the tubing through the polystyrene tray and use more tape to secure. This join doesn’t have to be waterproof.
5. Take the newspaper and roll it into lots of long sections, then twist them. Wrap them round and round the tubing to build up the shape of your volcano, keeping them in place with tape. You can also make the newspaper into balls to get a different effect.
6. When you’ve made the shape you want, tear up more newspaper into strips and papier mache them onto the volcano. It works well if you put a whole sheet around the volcano first, to make it easier to attach the strips and also to get lots of nice ridges you can build on.
7. Leave to dry.
8. Paint! I can’t remember if I painted mine all one colour first or if I sponged all of it, but at some point I used a sponge to put the paint on to get a grassy effect.

And now, of course, you need to erupt it!

You will need:

• Bicarbonate of soda
• Vinegar
• Red food colouring

1. Dump some bicarbonate of soda in the bottom of your pot (you can drop it down the top of the volcano). I just guessed at the quantities: it doesn’t really matter. Just make sure there’s plenty.
2. Pour in some red food colouring to make the ‘lava’ red. If you prefer, you can use orange/blue/yellow/whatever. With no colouring, the ‘lava’ will be white.
3. Put the volcano wherever you want it to erupt, bearing in mind that this is best done outside!
4. Pour vinegar down the hose. It’ll take a few seconds for enough foam to build up but then the volcano will begin to erupt!
5. Keep pouring until it doesn’t seem to be having much of an effect (when the bicarb is gone, there won’t be any more foam) and then clear up the mess.