Most kids go through a stage of being unable to tie a balloon without it farting off across the room. Water-bombs can be even worse, slippery little devils that they are.
This simple jig makes tying balloons (especially water-bombs) a lot quicker, and makes it a lot easier to build up your ammunition for April Fools.
Step 1: Materials
The jig must be smooth and snag-free, or every balloon will burst.
For this prototype, I used a dead Sharpie pen and some spare timber.
Tools included a small saw, sharp knife, drill+wood bit and a circular file.