Lol, I was a right terror as a little kid. Had a lot of fun with pyro and explosives. One of the most fun was building shoulder-launched rockets and launching them into abandoned buildings
Nothing like a satisfying kablooey, accompanied by a whole load of smoke and flames to set one's heart racing. Thermite is another fun mixture/range of compositions to play around with, not explosive, excluding thermites based on copper oxide, along with a few other unusual metal oxides.
Thermites are a mixture of a metal powder and a metal oxide, the fine metal powder serving to strip the oxygen from the metal oxide, and in turn, become a metal oxide itself, reducing the original metal oxide to molten metal, accompanied by a veritable volcano of sparks, and a several thousand degrees C flame. They burn under water, along with the ability to keep going in a totally O2-free environment, can be used for welding, or metal casting into moulds. Or to cut through metal objects. And of course, for destroying stuff in a most effective manner xD
Perfect for incendiary grenades, or for incorporation into rocket-propelled munitions, do-it-yourself satchel charge type devices and the like. Lol, stick a bucket of thermite on a car bonnet, and it will never move again, ever:P
The common, prototypical thermite composition is a mixture of fine aluminium powder and iron oxide. Incredibly hard to light, but once it IS lit, it cannot be extinguished, pour water on it and it will just break apart into H2 and O2, fuelling the blaze. Needs sustained heating with a propane torch to ignite it, or more practically, the use of a strip of magnesium metal. Hit a burning thermite charge with a CO2 fire extinguisher? thermite burns hot enough to split CO2 apart and just add carbon and oxygen, to burn like fucking fury. Halogenated fire extinguishers, like halon? not 100% sure, but IMO quite likely to yield nasty stuff like phosgene.
Impossible to put out, a shower of sparks, 2000 degrees 'C flames, burns under water, so stable one can quite literally wallop it repeatedly with a sledgehammer without the merest fucking suggestion of it igniting, no possible accidental ignition of just plain ol' uncomplicated thermite powder, good for casting, welding, cutting through solid steel, what more could one possibly ask?
Thermites can be modified, using sulfur powder, to lower the ignition temperature, that type of composition is known as a thermate.
What else...building my own fireworks from scratch was a lot of fun. Roman candles, rockets, bangers that make anything available off the shelf look like a little kid's toy, air-bombs that again, make off the the shelf airbombs look like something you might give a 5yo kid to play with ....bugger the flash powder content of something like 50-100mg, give it a couple of grams, and ohboy, they go off with an ear-splitting bang:D