53 replies to this topic

[brocade]

Just wondering if any of you can help me out im after a good golden brocade star mixture to go with my 6" ball shells you know the type where the golden sparks hang in the air for many seconds

[robert johnson]

Not exactly what your after because you have not mentioned the density or required length of the tail. but if you can handle it and are willing the best comp I have seen and used utilises Lampblack,It come's from David Blesser.

Potasium Chlorate 33%
Potasium Nitrate 8%
Charcoal 32%
Lampblack 22%
Dextrin 5%

Bewary the charcoal needs to be needs to be about 200 mesh and must be a slow burning type such as pine certainly not Willow, Coconut or Balsa as the density of the tail will reduce very rapidly.
You will find that this mix rolls very well around Bentonite covered 8 shot. But do build up the layers carefully and not to big, I would suggest from my experience about 8/9 mm and let them dry for a few days, before increasing their size to say 15 mm.Then final sizing for a 6" shell of 20mm. Once sized up let them dry for at least 2 weeks.
One important point on this mix is that when the comp is initially made it burns very uneven and slowly. this will rapidly change once the round stars has been formed and dried.
With this mix I think you will be very impressed, the hang time and density of the tail is far superior to any other comp that I have seen.The disadvantage is that it is filthy to work with. Once you have tried a 6" shell if you can build a 8" the difference is immence especially with the greater pyro in the sky.

[brocade]

Rob that looks great and as I stock all the required chemicals I will make some stars tomorrow The only thing that concerns me about the formula you have presented is there's no ali or antimony sulphide content to also include a partial glittering effect in the tail. however I will try this formula and let you no how I get on

[Pyromaster2003]

where can lampblack be bought in the UK?is there much of a difference between charcoal and lampblack because on a lot of pyrotechnics formulas it says use so and so lampblack or so and so charcoal?

[BOBO]

Lampblack is soot from burning hydrocarbons. It differs from charcoal in that it burns much slower, which is what you want in stars. It is very simple to make.

[robert johnson]

Very keen bobo, but do you know the density of lamp black? It makes Airfloat Charcoal look heavy. You are correct in theory, it is easy to make,.but not correctly and consistently every time. the mess would be horrific to make a few kgs. This stuff is pure filth to handle but unfortunately their is no substitute for the effect it produces.
To make Lampblack the best comes from pine. Two reasons why Lampblack is used is that the lampblack helps certain stars from being blown blind by promoting easy ignition, and on Brocade/Willow shells it gives a very high density /hang time on the stars.If you were going to try and make your own Lampblack it is vitaly important that their is no trace of oil[if using hydrocarbons] in the finished product as it will more than likely be used with a Potasium chlorate/perchlorate mix .

[robert johnson]

Hi their Brocade,sorry I did not get back to you last night . Believe me, when you have tried the formula you will be throughly pleased.
If you are looking for a Glitter / Flitter try the following
Potassium Nitrate 41%
Barium Nitrate 16 %
Sulphur 9 %
Antimony sulphide 8 % [ not trisulphide]
Aluminium Flake 13 %
Charcoal 13%
Dextrin 5% [or little as possable]

The aluminium must be Flake not atomised and is fairly critical on partical size. I use 120 mesh .
Also note this Formula is Glittter and not Flitter. Good luck with your brocade comp.lets us know how it works for you.any thing else you doing?

[brocade]

hey Rob thanks for all the help on this. Made the star mix as you suggested, heck is this stuff messy its been a long time since I last used lampblack and I had forgotton just how messy it is, however I am sure the results will prove worthwhile, as you suggested I have rolled these cores to 9mm diameter and will leave them to dry for a couple of days. thanks for the suggestion on glitter/flitter ill proably give this ago after getting this lampblack star working

[robert johnson]

Excellant stuff. It's great to be talking about fireworks and pyro. I have to say that the lampblack stars are one of the most beautiful effects you can get ,they also look very nice in a shell with a few blue stars.
I am into all things pyro, last year I finally managed to perfect Crossette 2 1/2" comets candles [6 shot ]. fired together in 3's 0r 5's the timing on the delays is accurate to milisec's right up to the last shot, and they all leave the tubes together, a lot of hard work but's it worth it. I was able to make a correct crossete pump and sleve from my lathe and milling machine.took a bit of time but the extra time involved was certainly worth it.
These also work extremly well in 6" shells.
If you are or become interested I can make you up the tooling for a small fee. I can promise you it is as good or better than the american stuff. All I would say is that crossettes for all the time they take to make are spoiled if you do them in straight colours try the lampblack mix as above or flitter/ glitter comps.
Good luck.

[Richard H]

Robert,

Do you have access to machine tools etc? Also what kind of prices would you be able to suggest?

[robert johnson]

I have access to a reasonable amount of machinery for tool making some of it is cheap and other items such as rocket spindles are a little more expensive,mainly because of the stainless steel base and the tapered aluminium spindle.


Will write to you personally about specific tooling.

[brocade]

Rob just let you know how things are progressing with the brocade stars, sized them upto 15mm diameter today these are growing at a very nice rate and since getting passed the basic core they roll nice and easy will let thes dry for a few more days before final roll to 20mm

[robert johnson]

Sorry Brocade,
I know its to late now, but in the rush to tell you about the formula I forgot to tell you about a very nice effect to do. I usually roll the lampblack comp on to a flash core which as the mix finishes burning you end up with a very bright flash which looks excellant if they all go off together. All I do is roll some standard 70/30 flash on to the 8 shot to a size of 6mm,leave them to dry over night and then continue rolling them with the lampblack mix the next day. I also forgot to tell you that these stars need no H3 prime as they light very easily.
By the way I do hope you have a proper vibrator! sorry I meant vibrating star rolling machine I was getting smutty.
I started of using a bowl which is fine for beginners but I learnt that you were not able to get consistency doing it by hand. It took a good bit of effort to get the speed control correct,and it was not cheap either. I will have to try and send you a picture of it.
Cheers dears

[brocade]

Rob if these stars are half as good as you reckon then ill be making loads more of these and after test shooting the ones ive made ill have ago at making them with a flash core. As far as star rolling goes i have to agree rolling by hand is time consuming and physically tiring on the arms and some time back I made a star rolling machine which rolls and bumps the stars to avoid clumping and achieving a more even size of stars.

[Pyromaster2003]

a flash powder core?the standare flash?where do you get the potassium perchlorate and aluminium powder from?