Volcano Eruption Toy

thingiverse

This is a toy model volcano, ready for action! Pour several spoonfuls of bicarbonate-of-soda into the cavity and screw on the plug tightly. Now mix vinegar with some red food coloring and use a syringe to squirt it in through the top quickly. The plug has a small hole that can accept a 2.5mm profile o-ring to help create a tighter seal. Although the plug may leak, it's not a major issue since things will get messy anyway. Do this entire experiment in a tray or outside where cleanup is easier.