8 replies to this topic

[pyrotrev]

Does anyone have a formula for silver palm (AKA silver coconut) stars please? For the uninitated these are large (usually pumped) very fiercely burning stars that throw silver sparks quite a way, even if lit on the ground. 8 to a dozen of them in a shell give a nice palm tree effect.

Edited by pyrotrev, 01 December 2007 - 08:54 PM.

[W.P]

Well, I don't have that particular formula but I believe I have an old "silver falls" star composition in my book:

49 Al
41 KNO3
4 S
+5 Binder

I'm not sure whether it's exactly what you're looking for but it does project sparks quite far out. You'd need a relatively drossy meal prime, preferably with some Al mixed in.

[Arthur Brown]

How far the sparks go is in direct proportion to their size so bigger particles of Al will travel further.

[MDH]

You could use large aluminum flakes and a simple black powder / AL base. I have found this pretty useful for the effect you're talking about.

[pyromaniac303]

You could use large aluminum flakes and a simple black powder / AL base. I have found this pretty useful for the effect you're talking about.

Not a bad idea, for increased brightness I'm thinking along the lines of the Bleser blond streamer comets, substituting the ferrotitanium for pure titanium.
Here is the original:

Bleser blond streamer #2
60 Meal Powder
20 Mixed charcoal
5 Dextrin
15 Ferrotitanium, 100mesh

I think you would benefit from using coarser titanium for a longer hang time on the sparks, as the comp is relatively hot you would have no ignition problems up to around 20 mesh.

[MDH]

A certian chinese company was willing to tell me they use coarse firefly mixed with finer AL on a perchlorate/gum base because nitrates and fine AL are a no-no in the factory.

I guess Titanium is too expensive?

[BrightStar]

I can't find the reference, but I remember reading that the perchlorate streamer stars tend to 'drip' sparks, whereas the nitrate based comets can be made to throw them off more energetically. In either case, the binder quantity and type is quite important and requires experimentation to get the best effect.

I noticed one comp on Passfire - the Degn L-104A Splitter Star:

Potassium Nitrate: 8
Barium Nitrate: 4
Sulfur: 2
Charcoal Airfloat: 2
Antimony trisulfide Chinese needle: 2
Dextrin: 2
Aluminium flake Bright 350 mesh: 1

This is described for use as 1-1/8" stars in exhibition roman candles.

[pyrotrev]

I can't find the reference, but I remember reading that the perchlorate streamer stars tend to 'drip' sparks, whereas the nitrate based comets can be made to throw them off more energetically.

That's precisely the effect I'm looking for, to get big bushy trails - I would estimate that sparks go in the order of 3...5m on some commercial palm shells. Thanks for ideas guys, I shall get pumping after Christmas

[MDH]

I have used a strontium nitrate/red gum/mg base with some coarse AL and a bit of charcoal - and it made a nice little fountain of slightly delayed white lights on the ground. Although without basically messing up the consistency of the whole composition, I wasn't able to get thick branching sparks like I suppose palm tree stars should have.

Maybe I should use palm tree charcoal next time. .

I know I'm terrible.

Edited by MDH, 10 December 2007 - 05:37 PM.