Making my first shells

[MisterSteve]

I'm making my first shells and I had a couple quick questions. I'm making the shells out of brown packaging paper wrapped into a cylinder shape. I was planning on making BP stars with some magnesium fillings in the mix. Then I was going to just have a core in the middle of BP or maybe just meal powder. Does this sound like it would work? Do I need to use wistle mix or flash powder for the paper shell to break enough to disperse the stars? I would appreciate any comments/suggestions for my first shells, Thanks

 

P.S. Will boric acid make the shells burn green?

[deadman]

The boric will not make the shells burn green. Nor the stars. You are definitley going to need to spike your shell. When you say wrapped do you mean glued and formed into a cylinder tube or just wrapped? There is plenty of info so take a look around.

[MisterSteve]

I mean I just wrapped and hot glued a few layers of packaging paper. So I do need to use wistle mix or flash powder? darn

[pudidotdk]

How big are you planning your shell to be?

[deadman]

Nobody mentioned the need for flash or whistle. Spiking may be where you got the idea I meant that. If you're not familiar with any term you see go ahead and check out one of the pyro glossaries found on the net. Spiking is the process of reinforcing a shell with string or twine. I have a big suspicion your casing is going to be insufficiently strong. Go ahead and invest some more time in your devices and you'll be much more satisfied than you would be lighting them quicker.

[TheSidewinder]

Deadman is correct, you do NOT need to use whistle or flash for break.

 

From your post, I assume you have little to no experience building shells. If that's the case, learn to WALK before you try to RUN. Much safer. Start with a BP break.

 

I've been building for 2 years now, and this year I *MIGHT* start to use whistle mix for my 3 and 4" shells.

 

(Although, 4" really doesn't need it. I got great results last year using 4Fg for break, and 2Fg for lift.)

 

M

[MisterSteve]

ok Thanks for the help. Yeah I did misunderstand with the spiking but I know what you mean now. I'll do that and test it out soon. The shells are about 1" in diameter and maybe 1.5" long.

[Mumbles]

With shells that small, you don't use a center canule of BP. You'd never be able to get enough in the middle for a good burst. What you want to do is fill it about 3/4 full with stars, and start adding BP. Fill it up to where you normally would, and start tapping the side to get it to settle. Keep adding and tapping until it is full. Try this out first, and see how it works. You may have to modify your spiking to get them to break well. I've seen several shells this small with only vertical spiking. Horizontal spiking caused them to burst out the ends too much.

 

I made some 1.75" last weekend. I used 7:1 KP on hulls mixed with the stars with about a tsp of Copper oxychloride catalysed whistle as a booster. They were rolled from 2 turns of manilla folder, and 3 turns of 30lb paper. They were spiked with 8 verticals, and about 5 horizontals using 20lb hemp twine. They were then pasted in with 2 layers of 30lb kraft. Some masking tape was used to seal from gas leaks, but I don't think it added anything structurally. They seemed to break nice and spherical, but they were attached to a shell about 600 feet in the air so it's hard to tell for sure.

[hst45]

MisterSteve, for easy introductory shells, take a look at the options;

 

http://www.wichitabuggywhip.com/fireworks/mortars.html#ees

 

Personally I would start with ball shell rather than cylindrical shells. I feel that they offer some advantages:

 

1) A ball shell uses less chems than a similar sized cylindrical shell (save $ while learning).

 

2) You don't need to spike them (reinforce with twine wrapping).

 

3) Premade hemis are cheap, especially in smaller sizes.

 

i'm a backyard display guy, and i do mostly 2", and they're a lot of fun, and very easy to produce in quantity. Some folks dispute this, but i think they're probably used to larger shells and find the smaller size a bit confined, but if you work with them all the time they're a breeze. Oh, and stay away from the metal-fuel stars until you've mastered organic fueled stars. Metals add more variables, like incompatabilities. Stay away from flash, too. BP break works o.k., and is way safer. Enjoy, and stay safe.

[MisterSteve]

Thanks for all of the ideas guys I'll get started and put some of those suggestions to good use!