114 replies to this topic

[JamesH]

BrightStar, althought the strobe frequency is higher than what you are looking for, that comp will still have some application - it will make some great shimmering stars!

[cplmac]

I wanted to avoid this – but I see nobody else want to take it on – so here is your blue strobe formula – from Bill ‘The Doc’ Barr Video.

63% Ammonium perchlorate, ball milled to a fine dust
10% Copper oxide (black copper oxide, CuO)
5% PVC powder
22% GE II Silicone #5000 (bathroom caulk)

I made this comp a few months ago. It burns a nice blue but did not even attempt to strobe. Aside from anything containing bright flake aluminum this is the nastiest mess I have ever worked with. Still have some, every now and again I throw a little on top of the delay in a rocket.
Someone mentioned endburning with a strobe comp earlier, you can do this, but it will just be an upside down strobe pot. I made a nice red strobe mix about the same time I tried the GE SiliconeII blue strobe formula.

Ammonium Perchlorate 60
Magnesium 100 mesh 25
Strontium Sulfate 15
Potassium Dichromate 5
Bind with NC Laquer, thin with Acetone

red strobe rocket

this is just some of the red strobe comp pressed in a 3/8" insert tube

[parabolic]

Hay cplmac,

That is one heck of a fast rocket!! I loved it,

could you explain how you made it? plus what tooling was used.

I understand that this is a thread regarding strobing,, so please feel free to PM me with the details of how you built this rockect.

cheers

Para.

[Mehofjack]

Question..

is the same material in a flare used in stobe lights, but is ingnited in patterns?

wondering because i found and old flare in my garage and wanted to see if i could make somthing cool outta it.

Thank You

Jake

[pyrotrev]

Jake: Strobe compositions are designed to inherently burn vibrationally, whereas any normal flare will be designed to burn as smoothly as possible. As to using your old flare I'll let the moderators give the "official" viewpoint, but please be aware that dis-assembling any pyrotechnic device is potentially VERY HAZARDOUS.

Edited by pyrotrev, 21 February 2007 - 07:21 PM.

[karlfoxman]

I missed this Trev, your correct. We do not advise you pulling apart and pyrotechnic device as you do not know whats in there. It seems your a beginner at this hobby so you will have very limited knowlage of what is inside this 'flare' it could have very nasty chemicals in it that 1g intake may make you very ill.

If it was a rocket flare then this is even more dangerous as pulling on the wrong part could cause it to ignite! The same applies to most hand held flares used for distress, there maybe some part that when you pull on it or scratch it the composition ignites and trust me a flare burns with high temps!

Why not read loads and understand how to make your own, much more rewarding than pulling something to bits to make something else.

[Mehofjack]

Thank you both and i will take ur advice and find out more before mesisng with things i ahve no idea are.

if u wanna help me learn that'll be awesome

[karlfoxman]

Thats what I like to hear! We will help you, search posts and ask questions and we will help

[Mehofjack]

Awesome!! kk well since i jus started all i do is take gunpowder (bought form local store) and get a hard papertube and fill it wit bp seal it (of cource wit a wick) and boom. All this does is a deent boom and SOMETIMES a big boom. But strobing sounds interesting and different. more of a show kindda thing?

kk first question is

what techniquly is a strobe and how is it made?

what materials and utiliy equipment will i need?

how dangerous and cool is strobing?

Thanks

Jake

Edited by Mehofjack, 22 February 2007 - 12:48 AM.

[portfire]

Hi Mehofjack. strobing is hard to get right, every element of the compostion has to be spot on (not talking from personnel experience, yet), even the pro's struggle from time to time.

As i always say, start with a small fountain,there easy to make and by adding different metals(be careful though) you can achieve loads of nice effects .

[karlfoxman]

In most cases you need magnallium (alloy of magnesium and aluminium), this has to be the correct mesh size. Magnallium burns with a vibrating flame thus gives a strobe. I have been making pyro for many many years and still not got the hang of strobes yet. Tried about 3 times but with not a good strobe.

Bangers are not that interesting, your best off making bp rockets or fountains to start. I would advise to get some books on pyrotechnics.

[Creepin_pyro]

what materials and utiliy equipment will i need?

There are two main systems used for strobing formulas. Of these two, the best strobes by far are made from Ammonium Perchlorate, Dichromate-treated Magnesium, and sulphates, but these are way beyond what a beginner should be messing with. Magnesium is an extremely dangerous and reactive metal, and you should know exactly what the hazards are (particularly those associated with Ammonium Perchlorate/Mg compositions) and how to minimise them before attempting to use it.

The other system uses a combination of Nitrates (Strontium, Barium, Potassium) and Magnalium. These are much less hazardous to produce, use easier to obtain chemicals, but generally don't produce very good colours, and can be hard to 'tune in'...

I guess the most simple strobe you can make would be the classic 'off-white' Barium Nitrate strobe, but it's always good to start small then work your way up to more advanced devices. Don't try to run before you can walk! Fountains are a great starting place!

[Mumbles]

In most cases you need magnallium (alloy of magnesium and aluminium), this has to be the correct mesh size. Magnallium burns with a vibrating flame thus gives a strobe. I have been making pyro for many many years and still not got the hang of strobes yet. Tried about 3 times but with not a good strobe.

Not sure where you heard that, but it's completely wrong. The "vibrational" burning of magnalium, if even true, doesn't have anything to do with strobing.

Here is a pretty standard looking red strobe from Shimizu:

AP - 50
Mg (100 mesh) - 30
SrSO4 -20
K2Cr2O7 - +5%
bound with 10% NC

There are two oxidisers in this formula, Ammonium Perchlorate, and Strontium Sulfate. This is the key. Strontium Sulfate is a very high temp oxidiser. If you just mixed SrSO4 and Mg, it would take a whole lot of convincing to get it to light, and often takes a starting charge of sorts, if anyone has ever made sulfate flash. Anyway, the ammonium perchlorate and magnesium react, smouldering in a way producing very little light. Once the heat is high enough, the SrSO4 and Mg react in a flash, and thus the strobing. This process repeats. The Potassium Dichromate is there to help with ignition and speed up the strobe rate.

Now, I know what you're going to say, this doesn't make sense for nitrate based strobes. Nitrate based strobes work on a similar process to glitters. They are generally rather high in sulfur content like glitters, 15-20 to even 30 or 40% sulfur. This is an indication of how they work. The Potassium/Barium nitrate reacts with the sulfur forming a slurry of K2S and BaS. This covers the magnesium or magnalium. After a bit of time, whether the metal melts, or diffuses out, not sure, but the metal reacts explosively with the slurry. This explodes a bit and shoots the slurry out, and a new layer must be formed.

[Creepin_pyro]

What about Guanidine/Tetramethylammonium Nitrate strobes without Sulphur/Sulphates?

[Mumbles]

I'm going to say that they react more like a sulfate alternative. I can only find a few formulas, and they used copper powder as the metal to make blue strobes. Really have no idea though. Maybe they form a ligand with the copper metal and that does something, who knows.

Edited by Mumbles, 25 February 2007 - 01:01 AM.