What is your opinion about these pre-fabricated canister shell halves

[dangerousamateur]

Hi pyros,

 

what's your opinion on such canister shells here:

 

 

http://www.pyrobin.com/files/canpaper.jpg

 

http://www.pyrobin.com/files/c5.jpg

 

 

How good do they work in practice?

How much pasting do you use on them?

[dagabu]

If you decide to use those half shells, you will need to roll up a few turns of chipboard or poster board for a liner first as there is no way of filling that shell correctly with a split canister.

 

You should consider following the traditional Italian method or use one of the many modified methods to make a simple canister shell. I have an old tutorial from 2009 you can use as well. It shows some very basic canister forming.

 

In the end, after you make a liner and make the spolette, fit that in the shell half, fill the shell, spike... Well, you get the idea, it is going to be cheaper to just make a canister so that you can ensure it is going to hold up under lift from the mortar.

 

Short answer: Yes, you have to add a pasted wrap band first around the seem, spike and paste wrap just like any cylinder shell.

Edited June 25, 2016 by dagabu

[schroedinger]

Sry dag, but you are totally wrong about these canisters.

The reason is, that these haven't anything in common with a canister shell, besides the shape. They are far away from canister shells or can shell that use a stiff body and plugs. These are nothing else then out of shape ball shells.

 

1.st you don't need a liner, you fill both sides and then close them up. Easiest way is to use the vacum closing method, else with a little work you can close it like every ball shell.

 

2.nd These canisters don't get spiked. You only paste them. So close them with masking tape, and paste with kraft. The strips are 1/8. The lenght is from mid ofthe bottom to the mid of the top. The tips of the strips get cut at a 45º angle of half the shell diameter. Or you pastenthe shell with one strip from fuse to fuse (360º). And accept some build up at the top.

[dagabu]

The OP asked about canister shells, how good do they work in practice and how much pasting do you use on them?

 

You may very well be correct in that they are out of shape ball shells, then they really are not canister shells?

 

Sounds like a semantic issue, if canisters, paste and spike after inserting a liner, if a warped ball shell then don't. No dog in this fight, carry on schroedinger.

[memo]

the main problem with them is they are not paper....

 

memo

[dagabu]

Why do you say that? Looks pretty papery to me....

 

http://www.pyrobin.com/files/c5.jpg

Edited June 25, 2016 by dagabu

[memo]

well hell, that's what I get for being lazy and not looking at the photos,,,, I ASSUMED that it was the plastic one that are being pushed on a other forum. those look a lot better than the plastics ones' iv still think I will stick with my case former .

 

 

 

memo

Edited June 25, 2016 by memo

[dagabu]

Agreed! I bet you could make a hundred in a day watching the game on the TV.

[memo]

bet you could, just wouldn't feel the same.

[schroedinger]

Yes they are paper. They may look like a canister, but these hemis are what the chinese often use for display canister shells of 3" and bigger (some 3" ca isters are made from a spiral tube).

 

The hemi is made from the same paper like nor ball shell hemis, just it is in a cylidrical form, not a round one. I use typically use 6 layers on a 4" overlapping by a half (so 12 sheet thick, 60lb).

 

How good they work in practice? Thats hard to say. You need to have some experience with them, then they work very well and even give you round breaks. But they brake is different to a real canister. The real value they have, is bringing up go-getters, hummers or reports that normaly don't fit in a ball shell of the same size.

[dangerousamateur]

I was not asking about normal canisters, but the ones i have posted.

 

 

But they brake is different to a real canister

Different how?

 

 

The real value they have, is bringing up go-getters, hummers or reports that normaly don't fit in a ball shell of the same size.

That is what I want.

And I admit im a little lazy, thats why I like these somehow. Also I hope to get away without spiking. I hate this work, because I never get it done symmetrical.

 

Unfortunately they are seperated in the middle, I would prefer a complete shell with a seperate lid for easy filling.

Especially when the inserts go over the full height and thus protrude over the halve. Bringing the halves together must be a pita in this case.

[dagabu]

I certainly wouldn't want to waste my chems on those...

[Mixer]

They would be better made the same length on two different sized formers so that one (in telescopic fashion) fits completely over the other, with a good fit and glued as they slide together it eliminates the need for spiking.

This would give you a good, well functioning canister shell.

 

I know, because I have done it!

Edited June 26, 2016 by Mixer

[dagabu]

Yupper, that is why I recommended the liner, you just cannot make an insert shell with all the voids filled solidly with a center split.

[mikeee]

With a thick walled tube you could turn male and female mating surfaces that could glue and couple together.

However with a thick walled tube you will be increasing the potential of large pieces of heavy cardboard coming at you.

Same problem with a thick heavy end disc, you increase the risk of someone getting hit with a large piece.

It is easier and safer to build the shell casing with standard pyro practices developed over the years.

[dagabu]

Agreed! And with a better result as well.

 

I guess I am not worried about disks and heavy cardboard, they all flutter down from the sky, never seen one come down at any radical speed. When the shells break (daytime) the paper all seems to stop propelled flight about 100' from the epicenter and flutter down.

 

Do you have a memory or a particular experience with end disks or heavy cardboard?

[mikeee]

Dave,

 

Your idea of a heavy cardboard tube or end disk may differ from my idea.

I have a number of 1/2" to 3/4" thick cardboard tubes along with end disks of the same thickness.

A sizeable piece of these types of materials would carry a distance, and you know how some people are in the hobby, proper distances

from shells being launched are not always followed. Just so long as larger shells are launched from proper distances this would not be

an issue. It is far safer and easier just to make the shell casing based on Fulcanelli methods.

I used to use the heavy wall tubes for bottom shots, my main concern is a poorly timed bottom shot going off at a low altitude.

The multi-layer bottom shot core is a safer method, since it tends to come apart in layers of paper, compared to thick wall tubes.

[dagabu]

Gotcha! I wasn't thinking about salutes since I make my bottom shots with newsprint and not heavy cardboard.

[MrB]

They would be better made the same length on two different sized formers so that one (in telescopic fashion) fits completely over the other, with a good fit and glued as they slide together it eliminates the need for spiking.

This would give you a good, well functioning canister shell.

 

I know, because I have done it!

 

I make salutes that way. Very efficient. I use bentonite clay for plugs, and there has been some debate as to if the clay might remain a solid and cause damages, but so far i haven't seen even fragments resembling more then sand.

B!

[mikeee]

MrB,

 

I would assume a properly rammed plug will shatter from the bottom shot going off.

It would be interesting to see a bottom shot go off with a slow motion camera frame by frame to see how the flash burst and shock wave affects the plugs.

[MrB]

Mikee, i've blown up a number of "ground salutes" over the years, and every time i've been trying to set them up so that if there were any "shrapnel" i would be able to find it. The most i've ever found is sand, mostly just dust, and confetti. Well, admittedly, there isn't much energy in it, but there has been larger bits of the tubes, among the confetti.

I don't have access to high sped cameras and such, so it's the best i've been able to do. But your right, it could have been a cool shot, if you were able to go high enough that you see the darn thing rupture, and not just "there one frame, gone the next"

B!

[Mixer]

I thought the OP was asking for an alternative for standard 3" shells without the need for spiking, and somehow this thread morphed into a discussion on heavy tubes and bottom shots.

[Mumbles]

I've never actually seen a shell made with those type of casings that didn't look like crap. They're fine for dump breaks, horsetails, propelled inserts, etc. If you want something pretty or with any semblance of symmetry, I'd suggest looking into other options.

 

It is possible to make shells using no-spike methods. There's a couple different ways to do it, but they essentially all rely on heavy flash bags. You need a lot of power to make up for the lack of confinement, and to help hide the shoddy materials and methods.

[pyroman2498]

I've never actually seen a shell made with those type of casings that didn't look like crap. They're fine for dump breaks, horsetails, propelled inserts, etc. If you want something pretty or with any semblance of symmetry, I'd suggest looking into other options.

 

It is possible to make shells using no-spike methods. There's a couple different ways to do it, but they essentially all rely on heavy flash bags. You need a lot of power to make up for the lack of confinement, and to help hide the shoddy materials and methods.

IE, consumer can shells , they have clay plugs and no spiking...

[dagabu]

IE, consumer can shells , they have clay plugs and no spiking...

Hmmmmm, inserts? Tube shaped but not cylinder shells in the traditional sense.