1569 replies to this topic

[broadsword]

i'd cherish a nice 1/2" walled tube

Second That!

[Erwin]

I have 3" tubes with 19mm walls and you just brought me up the idea of making areal salutes .
Should make some BP coated rice puffs now, but flash makes a nicer flash up in de sky .
Maiby making BP salutes with some flash salutes in it .

[ProfHawking]

actually i just mesured my tubes, they are 3/8" thick, so almost as nice. i have 10 of them at the moment and a nice 3 tube rack. I think i might try a bp salute then. If i mill my meal to a nice 3-4fg and put it in a 3" hemi, how much bp do you think i need to make a nice crack?

[adamw]

Before you get working on your 3" flash salutes, think about the safety and nusciance factor.

A can shell with about 5 smaller salutes can be a lot more effective, safer and satisfying than one huge bang.

[ProfHawking]

i dont think any of us are talking about 3" flash salutes.
i mistakenly assumed thats what it was, but it was BP. therefore it should be a lot safer than flash, or pretty much as safe as fireworks gets. Although you are right, precautions must be taken about people in hearing range etc. I would expect a large salute to be part of a larger display rather than the only thing, thus being more accpetable in any viewer's eyes.
Fiting 5 smaller salutes inside a 3" shell might be a challenge. they would have to be pretty compact...?

[aapua]

OK, hi again! Hopefully this time it works out to show you my very first attempt to make my very first 6?? shell. Here come the components:

http://www.hot.ee/aapua1/6/shell1.JPG
http://www.hot.ee/aapua1/6/shell2.JPG

Simple rubber ball, around it I made my shell. Without paper, just dipping into the PVA solution and then rolling in sawdust / dextrin mixture.

After 4 times of dipping and rolling the hemis look like that:

http://www.hot.ee/aapua1/6/shell3.JPG
I should actually say that one time dipping/rolling was too much...

Next is the burst charge. 150 grams of it packed like this:

http://www.hot.ee/aapua1/6/shell4.JPG

Instead of regular stars I decided to use small, 1?? shells. They are different delays blue, green and red peony. All together 28 pcs.

http://www.hot.ee/aapua1/6/shell5.JPG

Next are small shells I call ?spinning silver?. All together 15 pcs to form a circle in the centre of the 6?? shell.

http://www.hot.ee/aapua1/6/shell6.JPG

And half shell loaded with burst.

http://www.hot.ee/aapua1/6/shell7.JPG

Now all I have to do is to load the ?stars? in, put two halfs together and again, dip and roll, dip and roll ?til the size required. Let?s hope it will work as hell!!!

Btw, any suggestions, how much BP should I use for lift?

[Yugen-biki]

It?ll be interesting to se how the yellow plastic ball in the middle with burst will performe. I believe it's going to retard the burst force.
Why not a thin paper bag? This way the burts bag will keep the stars firmly in place as you fill the bag. It the stars are lose in the shell and are allowed to move just slightly the break will be deformed.
Compare this twnikle shell that had some lose stars in it: http://www.a0tu.com/...er/Twinkbad.avi
With this one with all stars firmly in place: http://www.a0tu.com/...inchtwinkle.avi

I liked the ?spinning silver? tubes!

Shimizu states that about 3oz (85g) is enough to lift a 6" spherical shell.

[aapua]

It?ll be interesting to se how the yellow plastic ball in the middle with burst will performe.  I believe it's going to retard the burst force.
Why not a thin paper bag? This way the burts bag will keep the stars firmly in place as you fill the bag.

I liked the “spinning silver” tubes!

:-)

Shimizu states that about 3oz (85g) is enough to lift a 6" spherical shell.

Why pretty hard-surface inner shell and not thin bag? I have opened some amount of shells, both chinese and russian type (don't anybody start to yell at me - I knew exactly what and why and how I was doing) had strong inner shell as a burst holder. Holes in it - it was said to help igniting stars around it. Seems like first, before pressure rises above shell breaking point, the stars are already ignited. I suppose that thin bag can't keep the stars in the place, especially when they are too heavy. Think how powerful is the uplifting force!

[paul]

Hm I don?t seem to aggree with you aapua...

If you have alook at these 2 pictures


Picturey copyrighted by www.feuerwerk.net


you can clearly see, that the huge amount of bp-coated rice hulls fill the whole rest of space in in the shell.

So I think that the stars are kept in place by this. If you shake such an finished shell you can?t hear anything moving in the shell if it is well constructed.

And all of the shells posted I?ve seen so far in this forum use this method or this method with a flashbag in the centre and they all worked nice.

So I doubt if this additional expenses are worth it...

Just a thought....

Edited by paul, 16 March 2005 - 12:09 PM.

[aapua]

Hm I don?t seem to aggree with you aapua...

If you have alook at these 2 pictures


Picturey copyrighted by www.feuerwerk.net
you can clearly see, that the huge amount of bp-coated rice hulls fill the whole rest of space in in the shell.

:-( Now it's too late to change anything, my shell is almost ready... Hopefully it still works as I'd like to see, and hopefully in few days here will be a nice video of its working ;-)

And anyway, the question remains (at least for me). Even though chinese fireworks is so extremely cheap, I seriously doubt that they use something useless in it. Even some 3'', mostly 4'' and 6'' shells had pressed cellulose inner shell. And the only 12'' I've seen open, had inner shell that seemed to be even stronger than outer one. Why the bloody hell? Just could anybody give any suggestion, why???

Btw, in Discovery Channel there was a picture of a company making fireworks. It might have been 8'' or 10'' shell they demonstrated. This had also pretty "solid" inner shell...

Edited by aapua, 16 March 2005 - 01:16 PM.

[paul]

I?ve seen this documentation, too I think. And as far as I can remember, this mentioned shell was a double petalled round shell.
And these shells of course need an second, inner shell to get the desired effect. Anyway, these inner shells normally are quite thin and not as thick as you mentioned it...

But I am not completely sure about that. Was there only the burtpowder in in and no other stars?!

[aapua]

But I am not completely sure about that. Was there only the burtpowder in in and no other stars?!

If you ask so suddenly, I'm not so sure, it was time ago... I remember at least few had inner shell filled with BOTH small stars and burst powder. Btw, I learned not long time ago about BP covered corn or rice, I used to think they were stars earlier! (What a fool, eh?) It's because I almost never use BP at all

[Yugen-biki]

The method of useing a smaller shell inside a bigger is soetimes use in bigger shells to make a petal. This is not needed but makes the construction of large and heavy shells easyer.

-Shell constructions-

The burst bag will not break when the shell lifts. If the stars and burst are firmly stacken in the shell the force will travel through it like a solid ball.



I don't say your shell will not work, but I would not have done like that.
It may not be wise to base your constructions on how other pyrotechnical factories have made theirs. I try to follow Shimizu's and Lancaster?s instructions because I know that what they say is going to work if done correct. This doesn?t mean you are wrong. It is because of people like you new inventions and methods are formed.

Edited by Yugen-biki, 16 March 2005 - 02:49 PM.

[BigG]

Okay Cool down boys?.

First, I must admit I seen many open shells, and the only time I've seen a solid centre was when making double petal shells. In such shells - the inside shell sometime is ignited by making holes in it for an easy fire transfer. David Blesser used this technique specifically in his procedure for a double petal shell and it gives very good results. The need for a solid shell on the inside is to maintain the circular pattern in the second Patel.

Stars and flash bags are mostly placed inside tissue paper only, where some filler is used to stuff the shell to its entirety. They even overfill it a bit so when closed the content does not move. There is no need, and it is more expensive to use a solid centre for flash bags and stars for any other purpose.

Saying that - I see nothing wrong with trying it and check the results. If it works, it works - we are not that concern about commercial reasons.

The modern Italian shells made in America for example, never use string and are made using pre-cast shells (either paper or plastic) - the effect is still quite impressive, but in my opinion - the original method gives better results. Mind you, as enthusiast doesn't care much about money - they can afford doing it the traditional way - while a commercial American manufacture cannot.

[paul]

Hey guys, I hope you can help me. As I read the Shimizu The Art, Science and technique I saw this:



It?s a snippet made with a digital camera from ME of a friends ORIGINAL book to show you what I mean, so don?t even worry if this is from an eBook or something


So, Shimizu states using non-pasted kraft paper for cylindrical shells. I used pasted paper the whole time and sometimes really had trouble folding the dried rock hard tubes. So, this would be great if you could use NO paste in the first instance.

EDIT: I?m asking this because I doubt that these shells are strong enough although they get finished with pasted cottonstring + pasted paper....


Has anyone tried this before ?!

Edited by paul, 23 March 2005 - 10:09 AM.