Fireworks Blog

One of the most present effects in fireworks, are crossettes . A crossette star or comet basically consists in splitting a star in 4 similar parts by the explosion of a small bursting charge ( usually flash powder ). The crossette stars or comets are made using the desired star effect composition in the pressed form and they contain a cavity with a cross format. That cavity is filled with some burst composition like flash powder. The whole star / comet body is protected with kraft paper and the bottom ( the cavity side ) with a cardboard disc, so, only one side is exposed to initial fire and usually it is primed for better ignition start. Crossettes are used both in Shells and also in Roman Candles (look this post to read more about Roman Candles) and essentially the efect is a burning star with an explosion at the end splitting the remaining of the star in 4 similar parts. Below, you can see a draw explaining the structure of a crossette: Below, you can see what the effe...

In Thailand, there is a traditional massive rocket festival called Bun Bang Fai . Usually, it happens between May and July and is influenced by Buddhist celebrations related to fertility rituals to celebrate and  "encourage" the coming of the rains during the wet season. Along with music, dance and beautiful decorations, there are great "homemade" blackpowder rocket ( this is the Thai word for rocket:  จรวด  ) competitions. The rockets are really big, mainly made of bamboo and some of them can contain up to 1 ton of powder inside and have a length of about 7 meters! You can see some of these rockets in the YouTube video below: You can see in some videos, those rockets going "CATO" (Catastrophic Failure) during launch. Many of those rockets also have a parachute to help them fall slowly into ground.  

In a past post, I have talked about the Portuguese rockets (click here ). Unfortunatelly, some years ago, the Portuguese Government banned rockets during the summer season because of some forest fires eventually caused by the falling of glowing rocket parts. Anyway, Portuguese pyrotechnics found a good way to keep the shows in a legal way with almost the same look of the tradidional rockets - replacing them with shells! The internal components of the shells are very similar to the ones inside the rockets - some black powder and effects (mainly stars, whistles and flash reports). You can see in the video below one of these effects at night: This is just a little sample, but there are a lot of different effects. My main idea is to show you how Portuguese traditional shells / rockets defer from the rest in the world. The majority of these shells are 3 inches in diameter. In another post I will try to show you the internals of one of these shells, stay tuned.