eli5 why do fuses for explosives stay lit underwater?

Question

I’ve seen videos of people throwing firecrackers and dynamite and things like that into water and they still explode, but how do the fuses stay lit?

In: 128

Answer 1

FYI, a cheap black cat firecracker fuse is just paper and gun powder. If you throw those in water, the paper and gun powder will soak up water and it will not stay lit. An M80 has a waterproof fuse.
This is also why old, cheap fireworks don’t light, especially if you live in a humid climate, fuses absorb moisture from the air and won’t burn unless they are waterproof.