Some of my wayward engineering friends paid me a visit on this weekend, an event always marked by pranks and mayhem simultaneously creative and destructive. This time, it took the form of exploding cans of hairspray.
This is seriously dangerous; nobody should ever perform this experiment. Shrapnel could fly out of the hairspray cans at high velocity, or you could get burnt by the flammable contents. I will repeat: DON'T TRY THIS. EVER.
Now, the standard thing to do with hairspray is simply to squirt some out and light it on fire, like a little flame-thrower. But what if you could get the entire can to come out in a fraction a second? Easy enough with an air-rifle.
Briefly, we placed two cans of hairspray (we initially did it with one, but two is even better!) in this Asian-looking garden shrine thing, thoughtfully left behind by some previous owner of the house (it has seen hard service since we took over!). Then we surrounded the cans with burning newspaper, stood at what we considered a safe distance (wearing eye protection, of course), and shot through both cans with one shot from the air rifle. This released all the gas at once, which was ignited by the newspaper and formed a massive fireball, as seen in the photo sequence above.
Another sequence of photos—note that some fuel remains for a few seconds after the initial blast, burning at a slower rate.