Here is an interesting photo:
This is our volcano. I made it out of flour, salt and a few other ingredients. If you want the link to the recipe leave a comment.
When I made it I assumed it would dry in a day or so. A week and a half later it was still not dry. We painted it anyway and started the eruptions.
Baking soda, vinegar and a little red food coloring.
Which by the way WILL stain the rocks so be glad the husband makes you do it in the back yard and not in the front.
It was a lot of fun, and we plan on using the volcano until it rots or falls apart. I suspect the rotting will come first because we didn't dry it properly.