Has anyone ever made a film canister mortar?

[gunner1]

I saw one described on Skylighter and was curious. The author staes that since you're only using about 9 grams of FFFG blackpowder, there isn't sufficient pressure to rupture the pipe. If that's the case then it seems like a good way for novices to get started in aerial shells.

[Weasel]

I haven't made film canister shells, but i have made 1" paper shells, which are pretty close. I have had many of them break in a homemade paper tube(exetremely weak), and the tube was fine. So yes, they should be good for a novice. They can be kinda hard to work with though, as they are quite small. some pyros start with 3" shells, as they are easy to work with. I would only suggest starting with 3" shells if you have a nice open field to shoot them and a good safe place to make them.

[FrankRizzo]

I've made one with PVC pipe. Just put it in a coffee can, and fill the can with dirt or sand to surround the pipe. Film canister shells are actually a tough device to master into creating a good break, but they use very little in the way of chemicals and generate a little less attention than their larger counterparts.

[Gunzway]

Yeah, I've tried a few film canister aerial shells. I haven't had a good break with them but they are still good fun and obviously cheap and simple. I've used cardboard for the mortar just glued onto a plank of wood. I haven't have any problems with it, we're talking about a small device here which can be used in a backyard really. I used spolettes as the time fuse, but recently I have acquired visco fuse and I've had one or two tests with that. Just make sure you prime it well, I had one of the shells not ignite unfortunately; incidents like this are when a good place for launching comes in handy.

[Mumbles]

The big problem I feel with film canister shells is what they're made of. HDPE can't be glued well so there is always a seam that is weaker than the rest. It's properties that make it good for mortars make it not as good for shells. That stretching and tearing instead of shattering absorbs a lot of the burst energy, and makes it hard to make symmetrical breaks.

 

Since we're already kind of off topic, you might want to stick with more traditional shells for things this small. I know, not as convenient, but you'll have better success and it is easier to tune. Plus you'll need the skill when you start making big fancy 6" multi-break shells.

[swervedriver]

Here's a couple I made. They make good horsetail breaks and salutes, so they are actually not bad for small rocket headers. Round breaks are very hard to do with the HDPE, and as pointed out already, glue doesn't work well on them.

 

edit: I've shot many of these out of 1.5" pvc pipe. I'm not saying it won't break the pipe, but I've lifted 250+ gram multibreaks with 30 grams(!) of lift in the 1.5" pvc pipes without failure. That doesn't mean they won't shatter into a million sharp fragments though with that amount of lift. Mine were buried underground with only a couple of inches above ground. I think the sub-10 grams of lift is fairly safe, but I'd bury it like frankrizzo said.

 

 

Edited June 6, 2009 by swervedriver

[firetech]

I've used PVC for a while in my undersized shells and devices. I have never had an explosion. I am not recommending it, but it certainly has worked for me. Just do some tests with it...your PVC might vary slightly. And ALWAYS stay back-Better safe than sorry.

[psyco_1322]

I use sections of 3/4" PVC pipe to make small star mine to test fire stars from. I have a standard PVC cap on the end that has a hole in it for the fuse. If I overload the mine, which happens some times, it blows the cap off. It still seems to function just fine and doesn't damage the pipe. Just beat it back on and go again. One thing to note is that I tape the tube, only about 3" long, to a short piece of stick and stab it in the ground.