Question: Why did the volcano take a while to erupt?

Dominique Sleet answered on 3 Jan 2020:

The volcano relied on a reaction between potassium and water. Potassium is a highly reactive metal that can react violently when it comes into contact with water, producing sparks and flames however it is also very unpredictable.

Because of the dangerous nature of the reaction, we had the potassium sat waiting in a pot inside the volcano and then water would be squeezed from a distance along a tube into the pot when we were ready for the volcano to explode.

We had done lots of testing with the volcano and each time it reacted differently and it was our bad luck that the first attempt during the show, nothing appeared to happen when we added the water. At one point the tube responsible for carrying the water into the volcano became dislodged so that also needed to be fixed before we could proceed with the reaction. So there’s a bit of a delay during the show but that’s actually edited down from a much longer delay in the theatre whilst we played around with the setup ensuring the demonstration was safe before trying again!