- Firework fountains - This file will simple explain how to make a fountain like the kind you see on the fourth of july. First of all you need some flash powder. SLIGHTLY moisen the flash powder with a couple drops at a time with water. mold this into balls from about .177 cal. bb to a 22 cal. bb in size and allow them to dry for about 3 days in the hot sun. Then put all of these into a container nice and snug and stick a fuse in it not puting any lids on. Light this and you will have a nice little display with some practice. It is really cool when you make different colored balls for different colored sparks. Be Creative!