1569 replies to this topic

[Pretty green flames]

Saw this on the APC forum

Nice shells though.
Hopefully you'll film them

[PyroKid]

Nice work on the shells !

Very professional looking !

I'd love to see video evidence of how well these perform, if at all possible.

[karlfoxman]

Hey Peeps!

nice to find some people who also build fireworks, i thought i was the only one. does anyone here make their own paper ball hemis? i have found my ones perform really well. also, anyone here build BIG 30-50mm roman candles? i have had a go at them and they work, need improving though.

[Sprengman]

I build my hemispheres from Paper by myself. I use a form made of aluminium or wood to press them. (from 2" to 8")

[karlfoxman]

I have been making my hemis using xmas balls, i first cut and file the raised lip off then cover the entire ball with thin plastic. then paste on 5 layers of gummed paper, let it dry and cut it in half.

i dont know if anyone else makes their spoolettes using this gummed kraft paper but using a piece 300mm long and 45mm wide formed on a 6.5 mm drill bit works great in my shells. never had one fail mind you i have only made twenty or so 3" shells.

a question for you plastic hemi users, do they produce better results than paper? i have never tried them but are keen to as making paper ones takes time.

p.s all you guys make so really great shells, i am amazed by them. does anyone from the uk meet up to shoot shells? i live in cambridge so the fen is a great place to shoot!

[Kembang Api]

Guys,
It's got to be something wrong with me. I can shoot a shell very high, the timing of the fuse is very good (round about 3 seconds) the burst is fantastic with a very nice bang. Man... the same old thing is keep happenning!!!! out of 70 to 75 stars they only lighted about 25 to 30. I had try to change the bursting charge with an additional of flash charge and still can't get it right. So please give me some advice!!!!

[Pretty green flames]

What star composition do you use.
What prime composition do you use.

[karlfoxman]

also how many layers of paper are using to cover the shell? i am sure you already knoe but too few layers can cause stars to not ignite. try shooting some stars with a star gun and see if they will light. if not maybe a different prime comp? sound very frustrating hope this helps

[Kembang Api]

The stars composition is taken from Alany data base with some modification to the following:
Red star
66 Potassium chlorate
15 Strontium Carbonate
10 Shellac
3 glutinous starch
9 Charcoal (airfloat)

I prime the stars with surfurless primer about 0.4 grams per stars and the star size is about 8 to 9 mm in diameter.

Stars had been tested with a star tester and each one of them shot out well (no blind stars, even when I shoot with 3 to even 4 stars at same time in a bigger pipe)

I pasted the shell 3 layers with 125 grams medium paper and the last layer with Kraft paper of 150 gram, so total of 4 layers.

it's very frustrating man.... i had been shooting more than 60 shell.

[Pretty green flames]

Maybe your brake is to strong. Do you use whistle, flash or rice hulls + BP.

Maybe you're just having some bad luck, belive me i should know.
Went to shoot 4 TT mines, and 2 canister shells. The mines didn't even want to ignite, and the shells flower potted.

I almost cried.

[Kembang Api]

Maybe your brake is to strong. Do you use whistle, flash or rice hulls + BP.

The break charges I used is 3:1:1 ratio (BP : KP: Rice hull) I have not try using BP:Ricehull break charges yet, maybe I will do it this week end. What would be the best ratio for 3 inches shell 4:1 ratio or should it be higher.

I don't know about bad luck man... I had shot more than 60 shells and when come to stars shell they all fail. on multiple report shell they all when well.

Edited by Kembang Api, 04 February 2005 - 05:21 PM.

[karlfoxman]

i use 6:1 ratio and get good results. when you use flash do you but it in a bag in the center?

[Kembang Api]

thanks for the info of the ratio. I will try. One thing that I don't like about using BP on ricehull is the bursting colour. It's kind of orange flame and the charcoal dust that produce during the break. I like to have a clean break so that the stars look much better in their colour. With the 6:1 ratio this will be produce more.

If I use KP bursting charge it will not produce that kind of colour flame as well as the charcoal dust but than it's too strong. That's the reason I mix them both into 3:1:1 ratio. Maybe I shpould increase the ratio to about 3:2:1 ratio. I will try both than.

I did not have the flash charge in the bag. I just pour the FC in the middle. Should I pack them in the bag and insert it in the middle of the shell? How do you do it?

Edited by Kembang Api, 04 February 2005 - 05:23 PM.

[Pretty green flames]

It is common tojust put a couple of grams into each sphere half and then mix it a bit with the primary bursting charge to help improve the break.