Pirotecnia Posted September 16, 2012 Posted September 16, 2012 Hi, Today i've found the bottom of a 3" chinese canister shell.Like happens with the ball shells, they also put 2 fuses in their cylinders and different to italian, maltese or americam, they put them at the bottom, not at the top.
dan999ification Posted September 17, 2012 Posted September 17, 2012 my first three inchers were bottom fused, if you can build a shell well its fine for this size if you dont lift it too hard and its not too tight fitting, one came down ( hands on head ) so i top fuse and light the time fuse with the leader for extra security, havnt had a missfire since or a flowerpot ever but it pays to make sure it does not happen for safety sake and to not waste the work. Dan.
Pirotecnia Posted September 17, 2012 Author Posted September 17, 2012 (edited) Ahh, now i understand why the majority of canisters are top fused, because of the fuse failures due to excess of pression during the lift.However, i never experienced that, because all the times i fuse my shells at the bottom and never had a fuse failure, maybe because the string/glue i wrap around the fuse, preventing it to go inside the shell during the lift explosion. Some years ago, here in Portugal, the minor fireworks companies dedicated their works to make rockets. Now, rockets are forbidden during the summer season and all the companies have to make mortar shells. During the first times, i noticed in a show that all the canisters failed, making the flowerpot effect (like star mines), because them were bottom fused, without any fuse protection. Edited September 17, 2012 by Pirotecnia
dan999ification Posted September 18, 2012 Posted September 18, 2012 the smaller shells have less surface area on the disc and can be stronger than larger discs, the fuse hole is a weak spot, some use thin ply on larger shells partly to prevent this happening you wont get away with light construction and material an the biguns. Dan.
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