Aerial Shells

[Chris]

What would be a better way to start the new era of aerial shell discussion than by presenting my new work. All kidding aside, I've been experimenting a lot with different star comps, burst charges, shell construction etc. lately and I have put together a few shells to test these features.

 

http://www.pyrosource.com/pics/5shells.jpg

 

The main problem lately has been the burst charge. I'd really wan't to find a burst suitable for plastic shells that wouldn't require flash to give a powerfull break and on the other side, not require any additional pasting or spiking. In this matter plastic shells are proven to be inferior to their paper equivalents. One of my most recent subject of interest is whistle in it's many forms. Currently I'm looking forward seeing how my whistle coated puffed rice performs as break in shells. After firing those shell above, I will know much more about everything.......related to shells.

 

Id like to end with a small easter egg shell that Ifired a while ago. It was filled with red KP and chyrsanthemum 8 stars. http://www.pyrosource.com/video/easter_egg.avi

[Sason.net]

I have to say thats a relly nice shell you launched!

i assume that the whistle coated puffed rice will perform well .

,how much braking composition roughly do you put in your 1.5 "cylinder shells?

oh, and i hope that the launch of thoes shells that are in the picture will be successfull good luck

[Chris]

I've never actually weighted the ammount of burst in different shells. Generally I just fill them as full as possible. For small shells up to 3" I usually use granulated BP as burst as it seems to produce good results.

[Sason.net]

oh, so you dont use a particular wight of braking charg....

have you ever tried BP+ Mg 8-2 ?

its a very good braking charg it works well it is not as strong flash powder but it is more powerfull than BP and you dont need big amaunt of braking charg to brake the shell properly.

[aa92td]

Sasonet right, bp+mg 8-2\7-3 its a great breaking powder.

here is a video with my shell (italian shell):

c6 start

and Bp+Mg 7-3

http://briefcase.walla.co.il/data/a/g/w/a/...14/PA230016.wmv

[Pretty green flame]

Sasonet right, bp+mg 8-2\7-3 its a great breaking powder.

here is a video with my shell:

c6 start

and Bp+Mg 7-3

http://briefcase.walla.co.il/data/a/g/w/a/...14/PA230016.wmv

Doesn't the addition of more fuel slow the powder down. I'm pretty sure you could get a similar break using just BP on a carrier. IMHO that's just a waste of good magnesium.

[justanotherpyro]

The main problem lately has been the burst charge. I'd really wan't to find a burst suitable for plastic shells that wouldn't require flash to give a powerfull break and on the other side, not require any additional pasting or spiking. In this matter plastic shells are proven to be inferior to their paper equivalents.

I would beg to differ Chris. A lot depends on the thickness of plastic etc...Whistle mix in a 3 inch plastic shell gives a great break for me personally. It's all in what you are trying to achieve. Simple manufacturing, perfecting the shell or whatnot.

 

On a side note I just fired off a 2 inch easter egg shell that was great. One layer of duct tape pasting,seams glued together, and BP break. It was really quiet but still a nice effect.

[Chris]

You are right about the thickness being very important. Plastic shells generally fail to build up a high pressure before they brake. The braking characteristics of paper and plastic are therefore different. Using a hig power burst charge like whistle or flash gives the illusion of a strong brake. However, what is happening is that flash for example creates a very sharp but low gas producing reaction that strucks the stars out using the inital 'energy' created in the explosion. Now, when using pasted paper shells, the amount of pressure built up in the shell is much greater. When a good paper shell ruptures, it disintegrates evenly and the stars are, instead of being struck out, carried out by the expanding gases. This seems to be a very common theory and my experiments support it as well.

 

In what form did you use your whistle?

[aa92td]

Pretty green flame Iam imagine you are wrong.

Mg+bp flash is more powerfull then regular BP, you can test it yourself.

Its will give you better break, put it instead your BP (same weight).

Here is another shell (italian)-

Mg and Po_aqua stars

Breakpowder- Mg+Bp 7\3

Shell weight- 60 grams

Lift powder- 20 grams

http://briefcase.walla.co.il/data/a/g/w/a/...Agreatshell.wmv

[Pretty green flame]

Pretty green flame Iam imagine you are wrong.

Mg+bp flash is more powerfull then regular BP, you can test it yourself.

its will give you better break, put it instead your BP (same weight).

here is another shell (italian)-

mg and Po_aqua stars

breakpowder- Mg+Bp 7\3

shell weight- 60 grams

lift powder- 20 grams

http://briefcase.walla.co.il/data/a/g/w/a/...Agreatshell.wmv

Well you may be right but i still prefer regular BP on a carrier substance, not quite ready to sacrifice my Mg for use in burst.

 

Hmm...from the stats you gave for your italian shell you seem to use 1/3 of the shells weight to lift it. That's quite a lot, 20 grams of my alder BP will bust the mortar.

 

Would you care to share a video of your lift.

[aa92td]

You totally right, I made my BP with coffegrinder and its lesspower then ballmill BP.

I dont have a movie of my BP, but i will try to find.

I working now on my ballmill i hope to finish him in few month.

[Pyrohawk]

Wow that is a ridiculous amount of BP!! For a 60g shell I'd use 5g to lift it. Try pressing your lift powder, al93535 convinced me to try that and it made a BIG difference!!

[aa92td]

I press my BP.

i use pine tree charcoal.

Next time i will try to make it with willow charcoal.

The topic its not about my BP.

Back to topic.

[justanotherpyro]

You are right about how the gas pressure works Chris. The 3 inch plastic shells I have are very thick, and when the capillary action of the sealant closes it, it takes a lot of force to break the shell open. If what you are getting at is that paper shells have the most potential for strength, then you are indeed correct. Unless a company decided to mold plastic 3 inch shells that needed to be fired out of a 5" I.D. mortar, and so on.

 

My whistle mix was powder, straight out of a Picallo Peet.

[h0lx]

Talking about shells, has anyone tried using the plastic "suprise balls" from the large "gumball machines" as plastic shell casings, I estimate they are about 6cm in dia and snap together quite easy. Cost only 1/3€ each also and you get a free treat too:P

[Mephistos Minion]

h0lx thou art genious! I pass one of those machines every time I go to the shop and never realised what potential they had. I will go buy one later today to test its validity as a shell. If they are good I think I will call the manufacturing place and try to purchace the plastic ball sans the plastic jewlery.

[Kilo_G]

I'm not sure why people who are iffy about flash arn't about whistle. Whistle is strong stuff, and just about as powerful as flash. If you're concerned about flash try using a "slow" flash, such as a 7/3 perc/-325 mesh aluminum. It's not as "sensitive" or powerful and probably cheaper then whistle. You can also try using the fine powdered stuff in an overfueled formula (50/50 perc/high mesh aluminum) but it costs more. A lot of people seem to think that flash is like nitrogen triodide or something. As long as you handle flash with respect (i.e. don't kick it, rub it, toss it over your shoulder, pour a bunch on the floor and try to make a flash angle in it or otherwise be careless with it you'll be fine).

 

Still though, I guess whatever you're comfortable with you should work with. You should never ever work with anything you are afraid of because that causes you to panic and freak out, over react and before you know it you've got an accident on your hands.

 

My father once said to me (and all it took was once) "Nelson, if you're afraid of electricity or being zaped you're in the wrong trade and should quite, right now."

 

This applies to many things in life, especially in pyro. Working uncomfortably is working dangerously.

[justanotherpyro]

There are lots of random items that have potential to make a good shell. Like those plastic frosting cups that come in the tubes of cinnamon rolls. If your a janitor or know one, the tubes that hold the paper in the paper hand drying dispensers are really thick too.

[Pyrohawk]

I press my BP.

i use pine tree charcoal.

Next time i will try to make it with willow charcoal.

The topic its not about my BP.

Back to topic.

Yes sir........ But ya know the lift of your shells is actually very "on topic".

 

justanotherpyro: Thats a really good idea! I work in a department store and guess who has to clean the bathrooms every night Well we have those dispensers and I just noticed that one of them was empty tonight..... Assuming noone else changes it before I work next, I'll get the tube!

 

Has anyone besides myself tried wrapping spherical shells in fiberglass/ strapping tape?? I read about it somehwere. I tried it and it did seem to make a much wider burst but it could have just been me as I've only tried it on one shell so far. I will definately be trying it on my next as well though.

[Kilo_G]

From what I've read opinions vary on strapping tape. Some people say it makes a big difference, others say it doesn't. Personally I think the one thing that would make a big difference is the burst you use for the shell. Specifically KP, as it is supposed to work better with the more confinement it has. I've never tried it myself though. It doesn't seem like the extra time taping the shell justifies the tiem ittakes to add the tape (i.e. just use a little more flash or whistle). In the end though you're the only person that can make teh call. I'd say try it. Make 6 shells identically except 3 having strapping tape and 3 without video tape it if possible and compair results.

[FrankRizzo]

Talking about shells, has anyone tried using the plastic "suprise balls" from the large "gumball machines" as plastic shell casings, I estimate they are about 6cm in dia and snap together quite easy. Cost only 1/3€ each also and you get a free treat too:P

These little guys are usually made out of PE plastic, which is resistant to solvent glues. You could probably use hot-melt or CA glue to seal them up, but it won't be a hermetic seal like the one you get from PS hemis and solvent.

[justanotherpyro]

I'm going to try out some lluminum flashing tape. Very sticky and sturdy stuff but it is a lot thinner than duct tape. In the plastic easter egg shells, the " pasting " is important because some don't snap together very tight, and glue doesn't hold them closed all to well. To prevent a flower pot, the tape is important.

[Chris]

Talking about KP charges, has anyone used them in plastic shells? I remember reading that KP isn't really suitable for plastic.

[Frozentech]

Talking about KP charges, has anyone used them in plastic shells? I remember reading that KP isn't really suitable for plastic.

I've used KP on rice hulls with 2 grams of whistle mix in 3" plastic shells. Works well with the gold streamer stars I used.

[Kilo_G]

Most stuff you read says you shouldn't use KP in smaller than 3" or 4". I think it's hogwash (LOL I said hogwash). I've seen shells using KP burst and they work fine (all the way down to 1 5/8"). The key is properly gluing the shell. Also dusting all the stars with meal or granulated KP is important. You also need to use whistle or flash inconjunction with the KP if you're using KP on ricehulls for a break.

 

If you have a passfire subscription Lloyd has an excellent article this month on 4" plastic shell construction, which looks to be a much faster/easier/better working way to construct plastic shells.