When we were 10, my buddies and I ordered 2 books out of a back of a boyscout magazine entitled:
1) Improvised Munitions, and
2) Boobytraps & Incindiary Devices
Within a week we had made 2 batches of napalm (1 using styrofoam, the other using lye), a crude claymore landmine, a bazooka, and some other nifty gadgets...the coolest of which was an improvised gasoline-filled supersoaker (squirtgun), outfitted with a wooden dowel & zippo lighter. Sure, our flamethrower only lasted for a few minutes, but man, the neighborhood bullies sure respected our block after that incident.
I even wrote a fictional book based loosely on that incident, 20 years after the fact: three “inventive” kids take on Islamic terrorists bent on finding/destroying the Holy Grail. If there are any literary agents out there, send me some freepmail! :)