114 replies to this topic

[Creepin_pyro]

Does anyone have practical experience in mixing Ammonium Perchlorate strobe compositions? I'm having trouble getting it to work.

[sasman]

Hopefully i will be making some strobes soon...when you say problems what do you mean?..i remember bigG mentioning that it depend on what day you tried it?.. that indicates it may be sensative mixture? to atmospheric condtions...

[Creepin_pyro]

I can't get any occilation atall. Just burns like a normal star. I've tried three formulas. One with Calcium Carbonate, and the others with powdered celestite.

I'm sure these compositions are amongst the most sensetive. (Mg&AP are not friends) Mabye it's just not worth attempting when the felative humidity is around 70% Mabye I'll leave it till summer...

[sasman]

From the little i have read on strobes the mesh size of the Magnesium controls the rate of flicker? what mesh size are you using? and is it atomized? or granular?..If the mesh size is to small maybe its flashing to fast to notice?..or if you are only burning a small pile maybe the strobe is to slow ??? and its all burnt up before it has chance to strobe?..

[Creepin_pyro]

I'm not sure of the specs of my Magnesium

I have three different types. One smells, is a dark colour, and ranges from particles that I can see (roughly 0.2-0.6mm) and appear spherical, to dust.

The others are 0.5mm granular, and more granular which appears to be about 0.25mm.

Could do with a source of atomised 350mesh Mg...

I think I will try with the different types of Mg, with more finely powdered AP, and mabye altering the ratio of Mg to other ingredients. I might also try sieving the Mg - I have a feeling it contains particles way over 300mesh, which could up the burn rate to a super-fast strobe indistinguishable from a constant burn....

Another thing I've read is adding small amounts of nitrated organic substances, and there are formulas containing smokeless propellant. I might look into using nitrocellulose instead, but I'm not sure of the differences/potential hazards of doing this....

Tricky things, these strobes.

[Creepin_pyro]

Continued from the Sodium Bicarbonate glitter thread that I randomly posted in....

I'm having trouble finding all my notes on this, but here's one unfinished version of the formula. I'll do my best to dig out the rest...

40 Strontium Nitrate
5 Potassium Nitrate
21 Magnalium
6 Chlorowax
4 Copper Oxide
5 Red Gum
18 Sulphur

The formula in the video is similar to the above.

Here's a video of a ground test. This is a very small amount <1g burning in a line. I've failed to prime these yet, so no word on how they preform in the air, or how different strobe rates can be achived, but I think it's worth working on.

Kind of pink/lilac, and I much prefer it to the "white" strobes that are actually pale green.

Strobe vid (3.5Mb zipped)

[paul]

Oh, how sweet they blink ;D I like the colour. Hm I could imagine they blink much more and faster if they glide through the air. Would be nice to see them falling and flashing in the sky.

Edited by paul, 16 December 2004 - 08:26 PM.

[Creepin_pyro]

People - please feel free to replicate the formula and try them in the air I have a feeling Veline's prime should work. BP doesn't, even with Aluminium and Silicon added. As Paul said - the flash frequency might increase with them falling through the air. Should be a nice effect.

[BurlHorse]

People - please feel free to replicate the formula and try them in the air     I have a feeling Veline's prime should work.  BP doesn't, even with Aluminium and Silicon added.  As Paul said - the flash frequency might increase with them falling through the air.  Should be a nice effect.

Velines Prime Works, add +1% Silicon, works like a charm! Neat color too! Good Job!!

Stay Green

Bear

[KingVinny]

I've been using plaster of paris (calcium sulphate) for chokes and plugs on my fountains for a while, as its really cheap, and have seen that it can be used in strobe formulas. I made up some flash with it a while back and it worked quite well. So I tried packing some in a tube and gently compacted it.
Calcium Sulphate.................58
Aluminium 300mesh atomized.............41
Sulphur..................1
Not sure where I found this formula but anyway, I packed it down and stuck a sparkler in as a fuse since this stuff takes a lot of heat to ignite. When the comp had lit, much to my surprise, it started to strobe. It repeatedly flashed bright white a few times a second for around about 5 seconds. I'm not sure whether this was just a fluke though, and that it only strobed due to the way it was packed or something else. Does anyone know if this type of composition is known for strobing? If it wasn't just a fluke I would quite like to try and make some stars out of it since the white flashes were extremely bright. Not sure how I would prime them however, although they must be pretty easy to bind.

[alany]

According to my DB that is "plaster thermite" without the castor oil, normally expressed as:

578 Calcium Sulfate
409 Aluminium
10 Sulfur
3 Castor Oil

I only tried it once, it was hard to ignite, but a sparkler did do the job. Loose it just burnt like thermite. It could be cast into various shapes, but after casting I never ignited it successfully, I was too cautious of a steam explosion to hold the torch to it, and a sparkler couldn't ignite it. I never tried packing the loose composition into a tube.

Plaster flash is normally:

64 Calcium Sulfate
36 Aluminium (3u, dark pyro flake)

With spherical Aluminium it would probably be very hard to ignite.

[sasman]

Do you have to use atomised Magnesium powder to get a good strobe..On passfire i have just read that Granular Magnesium won't strobe.. has anyone made some good strobes without using atomised?..

[Yugen-biki]

I have used granulated mixed with flake like Mg. No problem at all. Atomized seem to work good to.

[broadsword]

Hi all! I am back after a long break from pyro due to a new job , but i have now got another better job that enables me to have the evenings free.

Anyway, I was considering making some comets, and I thought it might be good if the comet had some sort of flash at the end.
Would putting some flash onto something like a peppercorn (rather like making coated ruce hulls) work?
I think i would need to add a little Boric Acid to the KNO3:Mg flash, or would this still be too unsafe?

Or would it be more advisable to put a smaller star that has quite high aluminium in to produce the same sort of affect?

What do you all think? Its been a while since I last made anything so bare with me

Broadsword.

[LadyKate]

Anyway, I was considering making some comets, and I thought it might be good if the comet had some sort of flash at the end.

----

Or would it be more advisable to put a smaller star that has quite high aluminium in to produce the same sort of affect?
Broadsword.

I'm trying the smaller star idea right now. I'm making small comets - 1.5"

Note that in the following paragraph, I'm referring to 'flash' as a light without sound burst and not a salute formula.

I've been experimenting with flash cores embedded in the comet - I was using the Bleser flash core formula but it is hard to light so I coated it with the Shimizu igniter prime - but the igniter prime burns with a green tint. Interestingly, the igniter prime could almost stand on its own as a flash formula. So .. the quick answer is that I'm still experimenting myself. I'm not sure how you would make the flash positively occur at the end - the comets I make don't necessarily burn to a reliable end point - timing the star ignition would be hard. My thrust is to augment the contents of the comet with a few dozen stars and have them peel off as the comet travels upwards.

If you are talking about a flash explosion to split the comet then rough timing can be done - see Dan William's site for ideas: http://www.wecreate4...lliams/top.html

Broadsword calling Danny Boy??? Where Eagles Dare?