WARNING AND DISCLAIMER: If you are underage, then consult with your parents or guardians before attempting any of this. You are on your own - I'm not responsible for your actions or harm you may bring to others because of your actions. Making the items described below can result in injury or death to you or people in your vicinity. Some things mentioned here may be illegal to make in your city, county, state, or country so check the laws that apply to you before you attempt anything described here. These notes are not complete on purpose. If you are reading them and new to pyrotechnics, then you are making a mistake. Stop now - this page is not for you. Get a beginning book on fireworks (see Skylighter or American Fireworks News (very quick shipping) for a start) and read up. You can't make any of this work without more information so read up or join a club or ask someone to help you.
This one blew up on the launch stand. Note that it severed down the outside seam of the tube. This was probably due to a crack in the grain caused by bouncing around on the floor boards of my pickup.
Cracked open while packing - and I was almost done! Note that this one also severed down the outside seam of the tube. This seems to be a common failure mode - which makes me suspicious of the integrity of the tube itself. However, I did beat this one to death (got carried away while tamping). I've reduced this problem to zero by using a packing sleeve (see: Reinforcing the Rocket Tube which is on the rockets.html page).
Ok.. this one was definitely a mistake. I'm blaming it on hot fuel and loose packing and a tight nozzle. Yeah.. that was what it was.
Here is a film can that had two or three hummers in it. The film can lid was glued on so the can would burst. It burst ok, but one of the hummers was jetting when it did and it melted around the film can - it didn't escape. This was launched in the daytime and the film can went looping through the air in a weird jumping motion. The film can was molten when it landed so I think I should have used a paper shell - less danger of molten plastic in the neighborhood - or a heftier burst charge so there wouldn't be any chance of sticking to the plastic..
Above is what is left of a 3/4" cake tube which was schedule 80 PVC. See the sharp pieces? A salute blew up in the tube. These pieces hit the barrier and dropped to the ground. The rest went out into the field. Notice how sharp some of those suckers are. A good reason to NOT shoot PVC around spectators, eh? Oh.. and the mistake was that the shell was too weak to handle the lift charge - which was 2 grams of Benzolift (silly me!).
The cardboard tube is a 2" mortar that couldn't hold the lift powder charge. The story is long but the short version is that the strength of the powder was underestimated so 20 grams .. yep... 20 grams of Benzolift -- was used on a mine. Wow! Sure was loud! The good news is that there was no shrapnel - none - very nice. Cardboard, HDPE plastic and fiber glass are the safest materials for mortar tubes.