1569 replies to this topic

[italteen3]

Sasman AMAZING WORK! Keep up the good work man.

Im not positive on this but 6 grams may be a bit much. From John Donner's book on making exploding fireworks it says as you double the amount of Flash it is 8 times as powerful. Not being experienced with shells I dont know if that will blow your stars blind but that is what experimenting is for.

I would try some small shells that dont use a lot of comp, stars, BP, etc. one with flash and one with whistle and see if your whislte works when confined/ under pressure. It would probably look better too as the whislte wont create as bright a flash when bursting so you see the nice gold earlier on and your eyes are not adjusting to the flash.

Keep us updated!

[Rip Rap]

I have read that H3 burns faster under pressure .. but have not read that whistle burns faster under pressure?

Sasman,
I did a search on rec.pyrotechnics, to see if I could get any reliable source to back this up:
http://groups.google...zona.edu&rnum=9
This post was by Tom Perigrin PHD - he wrote Introductory Practical Pyrotechnics.

He says "Whistle burst has a very high pressure exponent on its burn rate, so that
in an enclosed space it rapidly builds to a strong explosion, or perhaps
even a high order detonation."

I want to use whistlemix but i still think its burns to slow?

The whistle, shown in your movie clip, would, break your shell more powerfully than straight BP - honest!
That shell of yours was awesome BTW. I prefer dense breaks. You have good shell building skills. Just dont think, aaaww, this whistle mix stuff is a big wuss. I'm going to bung 50 gms in here to make sure it works, because it is powerful stuff!! Make a 1gm whistle salute, just as a demo to yourself

[Yugen-biki]

I have done some Na-Benzoate and perc. whistle. I never got the whistle to be as strong as bought firework-whistles. Probably because they don't use benzoate.
But one thing I found was that it burns really fast as a lose powder. When I did my reaserch on benzoate whistles, I learned that it is very important to mill and mix the chemicals properly.

And another thing:
When I made my first 3" shells, I were not abel to get the burst as strong as I would have liked it to be. (I used H3 coated seed shells).
Doing some reaserch on how to solve the problem, I foud a formula in Shimizu?s book used to calculate how many layers of pasteing you need, useing different kind of paper.
I soon found out that about 5 layers of kraft paper, that I was useing, was about 10 layers short of what was the minimum.
Plastic shells can never get the same strength as multipple layers of paper. That is why stronger bursts are needed. In this way you don't have to paste. But star ignition araises as another broblem.

[Jerronimo]

Hi sasman,

First of all: very nice shell!!!

I use wistle all the time in my 3 and 4 inch plastic hemmies, never tried a 6'' though.
In 3'' shells I use 1? to 2 gram of wistle
In 4'' shells I use 3 gram of wistle

I allways make my wistle with potassium chlorate and sodium benzoate 70/30
I made a testvideo to compare it to your perchlorate wistle and it certainly burns faster.
If you give me your emailadress via PM I can sent it to you, or maybe somebody is willing to host it.

[alany]

You dump chlorate whistle onto meal hulls?

[Jerronimo]

No,no,no I use a flashbag to contain the wistlemix.

Here's a (poor) video of the chlorate wistle
burning

[BigG]

Of course - mixture of chlorate potassium chlorate and Sodium benzoate is much more sensitive then the same mixture employing potassium perchlorate, and required a physical separation (by means of a burst bag) from most star formulations.

[Kembang Api]

BigG Posted Yesterday, 11:25 PM
Of course - mixture of chlorate potassium chlorate and Sodium benzoate is much more sensitive then the same mixture employing potassium perchlorate, and required a physical separation (by means of a burst bag) from most star formulations.

Do you still need a burst bag for Potassium perchlorate and Sodium benzoate mix? or only for potasium chlorate mix!

[BigG]

Do you still need a burst bag for Potassium perchlorate and Sodium benzoate mix? or only for potasium chlorate mix!

Potassium perchlorate mixtures are safer, so there are many other ways you can put them in a shell without a bag. For example, you can paste them onto rice hulls just like black powder, or you can even dust your BP granulates with them (It's quite usual to have both BP and Perchlorate whistle in the same shell). Of course, you can just pour the stuff into the shell in powder form, but I generally worry that it will gather at the bottom and can destroy an even break (I did not try it so I can?t really say. I know a few people that just pour the powder in with good results.)

[Kembang Api]

Thanks BigG for the information.
I have never try to use this mix in my 3 inches shell most of my 3 inches shell used KP mix, I believe to produce a good break depend in a good pasting. I used 7 layer of 150 grams Kraft paper.

[sasman]

he

Edited by sasman, 25 October 2010 - 09:13 PM.

[pritch]

I think if there was like an annual award for pyro of the year, based on quality of fireworks displayed, then Sasman would be the winner.

Ive found a bunch of tough plastic tubes in my grandads allotment. Like the thick tubes used to lay pipes under ground. I've just subscribed to passfire so I'm gonna be trying to make some shells myself

[paul]

Woho, even better than the 3" red shell :) I like them. Im impressed by the big bang and the nice riund break. My last 3" was not as nice, cause most of the stars didn?t dry out properly ): And if only 7 stars lit, you cant see any round effect of course :)

Video 3", but only 7 stars lit.....

So, till the day my shells work as good as yours I?ll keep watching your videos :)

[sasman]

Yeah! thats what i like to see Vids of Homemade fireworks....I loved that bow tie Break!.. Those reds were superb and nice charcoal tail.. Fantastic....What Formula did you use and what size were they. I hope i can reproduce reds as good as that...

. Also that Tigertail to D1 glitter very nice....Daniel anymore Vids??..I wont be firing any more shells for at least a week or so as i have no stars rolled as yet but ill start rolling some hopefully in the next few days... Got a few ideas of the Formulas im going to use but i Hope you share the Red star formula used in that Bow tie break!!..