78 replies to this topic

[Peret]

Barium chlorate stars ... catch fire very easily.

Indeed. I've heard that stepping on them will do it. But a_bab and Pyroswede, you were right - I've never seen a green like that, and so far I only saw it in daylight. I don't even think these need a metal fuel.

[Potassium chlorate]

Indeed. I've heard that stepping on them will do it. But a_bab and Pyroswede, you were right - I've never seen a green like that, and so far I only saw it in daylight. I don't even think these need a metal fuel.

A barium chlorate Bengal certainly only needs shellack. I simply use a 9:1 barium chlorate:shellack mix, though you can change it to 8:2.

You can use the same composition for stars, but my favourite for green stars is Hardt Green #6:

45% barium chlorate
18% potassium /per/chlorate
6% red gum
3% charcoal, air float
11% magnalium, -200 mesh/<74µm
12% parlon
5% dextrin

Some people suggested that I'd leave the potassium /per/chlorate out, since potassium might impurify the flame, so I adjusted the composition to:

50% barium chlorate
8% red gum
5% charcoal, air float
14% magnalium -200 mesh/<74µm
18% parlon
5% dextrin

Though I haven't tested this one yet.

But, yes, barium chlorate is intensely green even in broad daylight.

[a_bab]

Parlon is an overkill there for sure. If you go for using the notoriously BC for stars, you go for the unbeatable green it produces, and it needs no chlorine donor for that. KP is added to speed up the burning time, as BC/Shellac is slow burning.

I'm guessing that these BC/Shellac 90:10 stars would be ideal for microstars (slow burners, very vivid colour).

Another good idea is to use military star compositions, as they would never use anything but thoroughly tested stuff. Unfortunately they are not cost side oriented. And there are some BC compos out there.


In order to stay on subject, I'd say that a thermite kind of prime would be the ultimate prime. It produces slag, and it's very hot for sure. Maybe some tungsten based prime would be a candidate, albeit impractical for most.
That's why the japonese primes contain minium for the stubborn compositions.

[Potassium chlorate]

The depth of the green colour is undoubtedly the best with the simple 9:1 mix, though one might need something to improve the light radiation at long distances, like Mg or MgAl.

As for the subject of the thread: I think you're right about the idea with the thermite prime, though any burst charge composition +10% silicon would probably do in 95% of all cases.

Edited by Pyroswede, 16 May 2010 - 09:51 AM.