One of my buddies used to build bombs when he was a teenager for fishing purposes.
His biggest project was over 10 lbs. of powder. He and a friend took it to a pond and an argument ensued. My buddy wanted to heave it in and then set the timer. His friend argued that they should set the timer and THEN throw it in because he was afraid the powder would get wet if they threw it in first.
The timer was salvaged from an old washing machine. It was to be wired to a battery and a long set of wires glued into the end of the pipe bomb.
My friend prevailed. They threw their pipe bomb into the pond and tried to set the timer.
BOOOOM! They were covered with mud and water.
Washing machine timers turn the machine OFF not ON.
They would have been blown to pieces if they had not chosen the (slightly) safer route.
BTW, he grew up and became an engineer on the Space Shuttle. Very nice, fun fellow.
Many of the smartest kid of the “boomer” generation experimented with rockets and explosives. I blew up a small lab at home myself. I ended up with only a few stitches next to my eye. It could have been much worse.