Ping pong balls are made from celluloid.
That celluloid is made by the nitration of cotton.
I just heard someone's chair fall over.
Yes, that's right kids. Ping pong balls are nitrocellulose.
Now, before you get all excited, the celluloid used in the production of ping pong balls has been esterified. If I am correct, by treating with camphor. This turns the nitrocellulose trinitrate (gun cotton - which can explode on impact - not good for the sport of ping pong) to nitrocellulose dinitrate, a plastic.
What this does is reduce the instability of the final product. Hence, ping pong balls are highly flammable, but do not exhibit the rapid combustion of guncotton.
This is actually advantageous for our application.
If the need ever arises for a water proof fuse, and you don't have any, its easy to make.
Cut up several ping pong balls and place them in a jar that has a tight fitting lid. Add enough acetone to just submerge the pieces. Allow it to sit and dissolve the pieces of celluloid. You can swirl the mixture about to increase the rate the celluloid dissolves.
What you want is a mixture that is about as thick as pancake syrup. You've just made nitrocellulose lacquer.
This lacquer is a primary binder in many explosives.
If the mixture is too thin, just add a few pieces of ping pong ball. If it is too thick, just add a few drops of acetone. If it dries out between uses, just add acetone until it dissolves again.
Now immerse a length of cotton string in the mixture. Wear gloves and press the mixture through the threads of the string. Wipe off the excess back into the jar. Lay the string to dry. If you hang it up, the mixture may run to the end of the string.
Once dry, cut off a length and light it. Drop it into a bucket of water and you'll see that it continues to burn.
As I mentioned, this lacquer is a primary binder in many explosives. Smokeless powder contains, what? Ah, now I see your thinking cap is on and you're thinking "improvised shaped charges".
Yes indeed. Yes, indeed.
Basic shaped charge
140 Grams of Nitrocellulose Detonated.