[Myrddin]

My amusement consisted of soaking cotton string in a potassium nitrate solution, then letting it dry to make a slow, smoldering fuse. Muriatic acid (used for pool service) and aluminum foil liberates plenty of hydrogen to fill a few balloons. I would tie the slow smoldering cotton string fuse to the actual fuse of an M80, then turn the package loose with 3 big hydrogen balloons. It achieved pretty good altitude before the slow fuse lit the M80 fuse.

[hattend]

http://www.youtube.com/watch?v=a0PqmkKeNmc

Acetylene makes a bigger boom