Underwater Volcanoes

If you’re ever looking for something to do that’s inexpensive—and a BLAST for kids of all ages—a baking soda and vinegar volcano is an old standby for a reason.

Simple ingredients… bubbling reactions… predictable results…

We always have simple science supplies around here, partly because I write about science and create experiments and activities for the books I write, and partly because we all love getting our hands messy as we discover new truths about our world.

So, on a particularly rough day recently… you know, one of those days where nothing was working (ever have one of those?)… I pulled the plug on the day and took out some play-dough, two film canisters, a couple of blue trays, some books about oceans, food coloring, baking soda, and vinegar.


Constructing an Underwater Scene


Just a quick note about materials – film canisters are super-cheap, super-versatile things to have on hand. Believe it or not, in this age of all things digital, your drugstores still have lots of them getting turned in every week. The best part – for you – is that they don’t want them. They throw them away every week, and will happily give them to you for free if you just ask. We use them for collections, to make rockets and volcanoes, and so much more. I encourage you to ask around and get some of these to keep on hand for last minute projects.

We’d been studying the Solomon Islands for our monthly geography club, and had discovered that there is an active, off-shore volcano there called Kavachi. This geographical feature captured the kids’ attention, and was the focus of a dry-ice volcano model that was presented at our club meeting (hopefully we’ll get that up and shared with you as soon as we finish playing with our leftover dry ice), and so it was the perfect focus for today’s “rescue lesson.”

Looking through the books, Trevor and Molly decided on some colorful features to add to their underwater scenes. Molly opted for neon colors, while Trevor stuck with a more subdued color scheme. Once the scenes were finished, we headed upstairs to the kitchen and started mixing…

First, we added baking soda and some old food coloring we had (unfortunately, the color was really old, and came out brownish and patchy, but the kids didn’t mind):


Molly Adding Baking Soda


Next, we slowly poured in the vinegar:


Trevor Adding Vinegar


And did it again… and again… and again… until the play-dough became slimy and started melting into a rather disgusting mess on the tray.


Erupting Volcano


A day saved… mostly because we ended up laughing about the mess instead of continuing to get on one another’s nerves… and some gooey, sticky fun had by all.

I suppose if you wanted to use this to teach your kids something, you could talk about those oceanic features you found in the books, or you could talk about the reaction between the baking soda and the vinegar… or, you could just enjoy the mess like we did!