made a few works bombs and exploded them in the toilet a couple times at school bahah... also burned a hole in a desk.. not very much but it was basically the equivalent of a fuse, just in a concentrated spot.. just some tin, corn starch and I forget the active chemical used but it was in stump remover.. light it up and its basically like those stupid little fireworks you get at the store for Fourth of July that make pretty colors and are done with in about 10 seconds... bahhaha.. Chemicals are fun..