canister shells

[mfstraydog1]

this is my first real post i have a few questions on canaster shells

 

first question ok i know there is info out there on can shells. here is what i have all formers are 1/2 inch smaller than the shell dia. i have the number of kraft paper raps. spiking patterns. the dia. of the cavate for the burts charge. but what i cant find is the recommended height of the shell and what is the former dia.is for a multi brake shell. is it the same as a single brake.

 

second question what is every one using for a brake charge in can shell. can i use rice hulls or would it be better to use bp.

 

third how many raps of kraft paer are on the out side of the spike layer.

 

if there is any info out there that i miss please point me in the right direction

 

thanks for the help

Mike Freeman

[Mumbles]

Not all shells are 1/2" less than the diameter of the mortar they are intended to be fired from. 7" and up need more space. I highly doubt you're intending to make such large shells though. I also tend to use a little larger of a former on very small shells, like 2" I roll them on a 1.75" former. They're fine in real 2" mortars, but pretty tight to too big in consumer mortars for class C.

 

The height is generally aproximated as 100ft per inch of ID plus 100ft. This is pretty high for small shells, but it becomes more appropriate as shells get bigger. It's hard to measure anyway, so as long as it is at a safe height I wouldn't worry about it.

 

Multibreaks are the same former diameter. Some with many many breaks use slightly undersized formers, but I wouldn't worry about it too much. The break height becomes hard to measure as there are more than one. There really are no rules set in stone. The maltese start breaking some shells 50-100 feet out of the gun, and they'll reach 6-700 probably, and keep breaking almost back to the earth. Generally 1/2" is the minimum starting charge on a spolette, which corresponds to about 1.5 seconds or a little less.

 

I use BP personally for canister shells. I think it makes them more solid. Some will use burst on some media though. With multibreaks, it gets a little dicy in my opinion. I don't like any soft spots where the lift can cause a shell to fail or collapse.

 

The outside has as many wraps of pasted paper as the number of inches it is. IE a 3" shell has 3 paste layers. A 6" shell has 6 paste layers.

 

You might want to see if you can pick up a copy of Pyrotechnica 9 and 11. They're collectively known as the Fulcanelli papers or articles, and are the gold standard on classic italo-american canister shell construction.

[mfstraydog1]

Not all shells are 1/2" less than the diameter of the mortar they are intended to be fired from. 7" and up need more space. I highly doubt you're intending to make such large shells though. I also tend to use a little larger of a former on very small shells, like 2" I roll them on a 1.75" former. They're fine in real 2" mortars, but pretty tight to too big in consumer mortars for class C.

 

The height is generally aproximated as 100ft per inch of ID plus 100ft. This is pretty high for small shells, but it becomes more appropriate as shells get bigger. It's hard to measure anyway, so as long as it is at a safe height I wouldn't worry about it.

 

Multibreaks are the same former diameter. Some with many many breaks use slightly undersized formers, but I wouldn't worry about it too much. The break height becomes hard to measure as there are more than one. There really are no rules set in stone. The maltese start breaking some shells 50-100 feet out of the gun, and they'll reach 6-700 probably, and keep breaking almost back to the earth. Generally 1/2" is the minimum starting charge on a spolette, which corresponds to about 1.5 seconds or a little less.

 

I use BP personally for canister shells. I think it makes them more solid. Some will use burst on some media though. With multibreaks, it gets a little dicy in my opinion. I don't like any soft spots where the lift can cause a shell to fail or collapse.

 

The outside has as many wraps of pasted paper as the number of inches it is. IE a 3" shell has 3 paste layers. A 6" shell has 6 paste layers.

 

You might want to see if you can pick up a copy of Pyrotechnica 9 and 11. They're collectively known as the Fulcanelli papers or articles, and are the gold standard on classic italo-american canister shell construction.

 

 

 

thanks for the info Mumbles.

Edited July 14, 2010 by mfstraydog1

[dagabu]

Some may disagree but I find that simple pulverone makes for the best filler and 2FA in a small cannula for the break works wonderfully. I will add a small amount of booster to my break if the shell is 3" or smaller so as to spike the pressures in the shell so that it breaks evenly.

 

1.5 times the diameter is the traditional method of a canister shell so a 6" shell would be 9" long.

[mfstraydog1]

ok i have to ask becouse i have not heard of pulverone. and thanks for the info on the hight of the shell. i was going to make the hight of the shell equeal to the dia.

[mfstraydog1]

nvm i found out what it is but for who that does not know here it is.

 

Pulverone is ball milled black powder that has been slightly moistened so that it just clings together and pressed through a fine screen (a window screen will work). The resultant granules are dried and used for a number of different tasks. While you can leave the black powder in the ball milled state for packing in tubes - it will be a fine dust and very hard to work with. Making pulverone out of it decreases the dust problem and actually makes the hotter powders useful as lift powders because of the air spaces between the grains.

 

Composition

 

 

Meal powder 100 Dextrin 5 Method

Take your meal powder and ball mill for a further 24 hours (doing this will really increase the performance). Sieve the black powder to remove the milling media and wet the composition with alcohol solution. Mixed until you get a nice thick solid paste (consistency of play dough or when you squeeze an amount in your hand it sticks together), try not to get your mix too wet or it will become gooey and useless. The trick is to add a little solution at a time until you reach the desired consistency. If you do make your mix too wet simply add more meal powder and mix together again until you reach the correct consistency. Take your paste and press through a mesh screen to granulate. Spread the granulations out onto a newspaper to aid in the drying process and place in the sun or similar for a few days. The resulting dried granulations of black powder is called pulverone.

 

Summary

Adding dextrin will slow down the burn speed of black powder (although very minor) so you may want to experiment with different amounts you add depending on your intended purpose. You can also use different sized mesh screens to achieve various grain sizes.

 

 

the info was from pyro guide

 

 

 

Thanks

Mike Freeman

 

 

[dagabu]

 

Pulverone is ball milled black powder that has been slightly moistened so that it just clings together and pressed through a fine screen (a window screen will work). The resultant granules are dried and used for a number of different tasks. While you can leave the black powder in the ball milled state for packing in tubes - it will be a fine dust and very hard to work with. Making pulverone out of it decreases the dust problem and actually makes the hotter powders useful as lift powders because of the air spaces between the grains.

 

I will just make one correction, I was speaking about traditional pulverone and that is pressed through a 3 to 4 mesh screen to make quite large grains. I have never lifted or broke shells with pulverone as it is not very reactive nor is it ball milled. You simply take all three chemicals in an air float condition, add very hot water along with 4% dextrin and form into a ball and press through a large opening screen.

[mfstraydog1]

I will just make one correction, I was speaking about traditional pulverone and that is pressed through a 3 to 4 mesh screen to make quite large grains. I have never lifted or broke shells with pulverone as it is not very reactive nor is it ball milled. You simply take all three chemicals in an air float condition, add very hot water along with 4% dextrin and form into a ball and press through a large opening screen.

 

 

thanks dagabu for the info. i have not yet tried that meathod i will have to give it a try.

[Mumbles]

One day if I have more time, I want to go through and correct all of the incorrect/poor instruction on pyro guide. It is getting better though. Dagabu is correct in that it is generally simply screened. I usually don't even bother with airfloated materials. My commercial charcoal and sulfur are quite fine. I use -60 mesh KNO3. It's a flammable filler, performance doesn't really matter. I often grade my granules after granulating. I granulate my powder through a 4x4 hardware mesh screen. After drying, I use shake through a 6 mesh screen. The largest granules get saved to fill in the top of shells to level everything off. I then use -6+24 for filling in the gaps in between stars and inserts and stuff. The stuff that passes 24 mesh is generally saved for the next batch, or regranulated. I don't know if it's really neccesary to remove the fines but it makes the process a little cleaner. There really aren't many fines once you get used to granulating. I have used the fine component for others things in the past. If I'm not planning to make any polverone for a while, I usually just burn it or add it to my primes to give it a granular surface.

[dagabu]

One day if I have more time, I want to go through and correct all of the incorrect/poor instruction on pyro guide. It is getting better though. Dagabu is correct in that it is generally simply screened. I usually don't even bother with airfloated materials. My commercial charcoal and sulfur are quite fine.

 

Great point Mum. I get hammer milled KNO3 that is just about as close to airflaot as i will ever get so that is what I use for pulverone. I agree that it would make no difference with the KNO3 since it all dissolves with the addition of the hot (boiling) water.

[mfstraydog1]

i found the Fulcanelli articles on line in a pdf format thay are a great source of info. thanks for the addvise mumbles

 

 

 

 

[angelluis]

this is my first real post i have a few questions on canaster shells

 

first question ok i know there is info out there on can shells. here is what i have all formers are 1/2 inch smaller than the shell dia. i have the number of kraft paper raps. spiking patterns. the dia. of the cavate for the burts charge. but what i cant find is the recommended height of the shell and what is the former dia.is for a multi brake shell. is it the same as a single brake.

 

second question what is every one using for a brake charge in can shell. can i use rice hulls or would it be better to use bp.

 

third how many raps of kraft paer are on the out side of the spike layer.

 

if there is any info out there that i miss please point me in the right direction

 

thanks for the help

Mike Freeman

go to skylighter.com they have everything go to the fireworks info and table chart there you will see everything that needs to be done like how many wraps for a canester or round shell, the canulle or cavate size for different size canester breaks proper hieght how much lift charge how much spiking ,the right size star for a shell,plus so so much more just on that one page ,then they have a part that says project plans they have so many tutorials,the kit project has some great deals for example they have a kit that brings 20 # 4" shells the visco the time fuse or fiftheen pound bp kit with red gum for granulation for $63.00 and so so mush more ,check it out,let me know if you found this info helpful?

[Mumbles]

It may have been more helpful if you included some links, and perhaps investigated the use of a period.

[mfstraydog1]

thanks for the info Angelluis. i have found all the info i think i need for know. skylighter is a good place to start. so is passfire. but most of all i have the Fulcanelli articles. witch it looks like most of the info on canaster shells had came from.