53 replies to this topic

[Jerronimo]

Dear fellow pyrotechnic enthusiasts,

For last new years eve I constructed about 15 kraftpaper ballshells and although
I was pretty satisfied with the endresult, I wonder if there is an alternative to pasting the shells with kraftpaper, because this is pretty time consuming.

I looked around hobby shops for some plastic balls but they are nowhere to be found.
Does anybody know an online shop where I can purchase these?or maybe a method to make my own?
And yes I know american pyroshops sell them but the shippingcosts/time hold me back.

[Pyromaster2003]

I once seen a site a while ago telling you how to make your own plastic ball shells.

What you had to do was get one of those white plastic disposable drinking cups and stand it on a baking tray and put it in the over on a low gas. The gradualy after 10 mins of so it would slowly flatten out and turn into this white round disk of soft plastic. Repeate this one more time to get 2 white flat round pieces of plastic.

Now you had take tw0, 7" squared pieces of cardboard and cut a square hole in the middle of each so that when you place one on top of the other you have a perfect square hole going throug hthem both. Now you had to cover one side of the square piece of cardboard wit htinfoil, do this with both of the pieces of cardboard.

Now take one of the flat round pieces of plastic and lay it ontop of a piece of cardboard you have prepared, let it lay on the side without the tinfoil on it. Now take the other piece of cardboard and lay the side without the tinfoil on, ontop of the piece of plastic.

The next step is to place this in a toaster for a few seconds do the plastic in the middle turn all soft. What you now had to do was take it out and press a gold ball into the square hole in the middle of the cardboard cut outs, this would then stretch the sort plastic through the square holes in the cardboard and form the shape of half a shell (half the golf ball). Cut this half a shell from the flat plastic to get your finished half a shell. Repeate this to get the other half.

This probably makes absolutely no sence at to you! I may take some pictures and do the procedure myself sometime to show you how it works. Its kind of like vacuum forming apart from there no vacuum. There is probably bits that iv missed out from the procedure aswel. It is actualy a hell of a lot easier done than said!

[Yugen-biki]

I made 8 shells for new yerar 03-04. I use Kraft paper and wood glue. A total number of 10 layers gives a nice burst to my 3inch shells. But I make them under a long period of time (1 month). When you use plastic shells the burst may become weaker and ununiform. To compensate you have to use flash or wistle comp to make the burst powerful again. The drawback is the danger of handleing these comps. You may use thicker paper to decrese the number of layers. I have tried that and the glue becomes more important. I find wood glue the best.

[alany]

I ordered some 2" ones from a US plastics supplier, which was very cheap, but yep, it took ages to ship them out here because I could only afford surface. They offered mortars and bases too, which were quite good.

I don't know if you have "Kinder Suprise Eggs" where you are? They are a children's candy thing, a kinder egg, with a plastic egg inside containing something to build. The egg makes a pretty good shell, a bit over 1" in diameter.

I assume you'd have those vending machines that spit out a toy in a plastic shell, normally half transparent, half not? Those work pretty well I've been told, but I've never tried them myself.

Shooting plastic is definately a lot less work, but I prefer shooting paper. The fallout is safe and biodegradable at least. You can make a pair of dies up, perhaps using plaster of paris and golf balls to speed making the hemispheres (or better the vacu-forming method with kraft pulp, as documented on passfire), but nothing really helps with the pasting in, it takes ages with lots of drying.

Canister shells are quicker and easier to make. I love them, but obviously you can't do the same things with them as you can with ball shells.

[Stuart]

If you want your paper moulds to dry quicker, add some meths or some other spirit to the glue. I find most things will dry in less than a night using it.

Stuart

[pyrotechnist]

Hi I make my shells with polystyrene balls i got from the art shop the sold 3 sizes but there is another size to that?s not there at the moment so they really have 4 the smaller one I like measures about 2 1/2". I have a large one a
medium one and a small one, which is very small. I cut the 2 1/2 inch shell up by the line around the middle into to pieces and start by getting some PVA glue and mixing with hot water but you can do it your own way. Then I made a
circle on the pc or oval and drew a square box around it to measure the area of the shape I want and drew line to the corners of the box and the centre
lines of the box. Until it came to the right shape and then made a circle in
the middle of the box to such a size all equal on all sides then drew
lines going from each side of the box e.g. were the circle is in the box fitting all the boxes lines top left right and bottom line the gaps that are left behind you draw the line on. By going from the middle of the box on the left side the left line in the middle draw it to the top end corner of the gap left behind bye the circle and box like here is the box [o] with the circle
in it and the gaps around the edges these
_ _ _
_[o]_ are like a triangle |/ the circle in the middle.
____
|/ \|
|\ /|
------ The shape you see in the middle is the shape you want this
_
/ \
\_/
then you draw the lines going to each corner of the shape until you get a
cross and a strike thru line in the middle of it then that were you add the
circle but put it in the middle. There you go then print out and cut the shape out and cut the lines.
In the shape until you reach the circle but done do this with the one you printed this is a stencil. Make replicas on the craft to make the same shape in a long row then cut out these and do what I told you to do with the lines and put in the glue solution and put around the former. And then ones you have got your correct thickness bye putting lots of these shapes on you leave to dry ones dry you should have a strong shell.

The picture of were it says at the side "are like a triangle" the first under score line is pointing to the top corner of the Square bracket. The second dash is pointing to the right hand side o the bracket like on the bottom the top should be the same. The third line should go to at the end of were it says "are like a triangle" here, to make a triangle. But the post didn't come out the same as when i typed them symbols out it was ok but when posted it changed it it took me a few edits until i got it right. Hope this is ok now and you understand it.

Sorry about the crappy drawings.

I got this from a pyro friend.

Edited by pyrotechnist, 04 January 2004 - 08:44 PM.

[The_Djinn]

If you look around some of the American supplier sites you can get the plastic ball shells. They come in sets which includes the two hemi's, top loop and a few other bits.
From what I have read out there they give a cleaner break than the papper shells which tend to have a weak spot here and there.
Personally I have been toying with the idea of buying some of the plastic shells as I dont always have a lot of time to devote to making papper ones.

Mark

Edited by The_Djinn, 03 January 2004 - 07:47 PM.

[alany]

I got mine from here:

http://www.pyroplastics.com/

Found the URL on passfire in the links. The site sucks, and you can't order online, plus the email you contact is a *hotmail* account, so I figured it was big risk. However, the person I contacted was great, she gave me good advice, minimized the costs and everything. It was a good experence all round, and very cheap and better choice compared to some of the more established places like (gulp!) http://www.cannonfuse.com/

[Yugen-biki]

The_Djinn

From what I have read out there they give a cleaner break than the papper shells which tend to have a weak spot here and there.

Yes if you use something other (or combined) then H3 like wistle or flash comp and if the paper shells are made by a tired chinese
I have glued a 2.5" shell with wood glue and 6 layers kraft paper and fired it 12h later with goor results. Plasic shells may work as good as paper but there is as many ways to make shells as there is pyros making them. I prefer paper.

[Jerronimo]

Thanks for all the replies guys.

I must say that pyroplastics website looks promising lowest prices I've seen to date, thanks for the tip Alany!
I'm thinking about ordering 3 bags 3" and 3 bags 4" I allready sent them an email regarding shippingcosts, hope they are not that steep .

Yes I know those kinder surprice eggs, as a shell on their own they will be to small for me, but they would be usefull as an insert in larger shells.

The method pyromaster mentioned sounds interesting, but I think the endproduct will be to "flimsy".

Thanks for the effort pyrotechnist, but your post makes no sense to me.

[pyrotechnist]

Ho sorry I will put a picture on for you. Do you have to put the picture on a server for it to come here cause that what it looks like? I will modify my post to a more suitable way of reading then thanks for pointing that out. I don?t think plastic shells are very good cause they make lots of shrapnel when bursting in the air which can be very dangerous for spectators watching the firework down below. So I suggest don't use these types of shells for yours and other people?s safety.

Edited by pyrotechnist, 04 January 2004 - 08:52 PM.

[Matt]

When i was young.... bout 7 years ago I had a 3 full garbage bags of nestle magic balls plastic hemispheres. 2 red 1.75" hemispheres that snap together, and they were bloody hard to get apart also! so now I sit here kicking myself. Anyone recall these things?

-Matt

[Richard H]

I don?t think plastic shells are very good cause they make lots of shrapnel when bursting in the air which can be very dangerous for spectators watching the firework down below. So I suggest don't use these types of shells for yours and other people?s safety.

That's not quite true. While plastic shells do present a slightly more significant fall out hazard, technically no spectator should be within a fall out zone, and all firers will be wearing PPE so the risk in that sense is negligible.

One issue that plastic shell does raise is the enviromental impact, i.e. where non-bio-degradable fallout is undesired or not permitted.

[pyrotechnist]

I don't like them much but never tried them I got some rockets at bombfire night which had plastic shells on top of them they were good. I got this plastic shell info from the book Fireworks: The Art, Science, and Technique By Dr. Takeo Shimizu ho said on the shells guide page about plastic shells aren?t good cause of shrapnel. But yer fireworks are away from spectators in displays but could still be an hazard to animals away from it walking around I will try one of these some day but like the originals the paper shells I like the best they may be a nuisance to make but I love em. And i like the paper shells cause they go into shreds insted of spiky peices of plastic. Is my spelling getting better.

Edited by pyrotechnist, 05 January 2004 - 11:18 AM.

[Richard H]

The spelling has improved, just need to work on punctuation, use of question marks, and paragraphs

Keep it up