4 replies to this topic

[Creepin_pyro]

I've recently been working with the "Blue strobe rocket" formula.

It has been great fun, so I thought I'd report my findings.

Here's the formula. Anyone know who to give credit to?

Ammonium perchlorate...............63
Silicone II.......................................22
Copper(II)oxide.............................10
PVC.................................................5

I've heard that the right Silicone smells of Ammonia, not vinegar. I found some unibond all purpose sealant lying around (translucent one) which smells of Ammonia, and have had no problems so far.
The Silicone was weighd out in a container, then everything except the Perchlorate was added. I just stirred it until it reached a uniform, sticky consistency, then added the Perchlorate. After lots more stirring, the mixture starts to thicken, and pick everything up from the edges of the container, forming a nice blob. Now It's very easy to handle, and can easily be pressed into tubes or rolled out to a sheet.

I started by trying this as micro-stars, so I rolled it into a flat blob, about 2mm thick. After about a day (I think) it is cured and can be cut up easily. They are VERY keen to take fire.


I loaded about 7g of these little stars into a 3/4" BP fountain with these results:
(note - turn down the sound if you are offended by foul Language)
Blue fountain (1.5meg)

I was pretty chuffed with that. I think a higher percentage of stars would work better - looks better when it's constantly flinging them out

I tried substituting 40% of the Copper Oxide for Strontium Carbonate, but the results weren't too good. You can see it on the right - less saturated, not much more purple.


I'm tweaking a formula with a higher percentage of Carbonate using Chlorowax, which seems much more promising.

I would think very carefully about making rockets with this, but I've done a small static test. I cut a strip from the original formula and rolled it up in lots of kraft, leaving a bit poking out the top. The finished motor (if I can call it that) was just over an inch long, and open at both ends.

Turn up the sound for this one! blue static test (800kb)

Now I see why they're called "flatulent blue smurfs" Hoorah for Silicone!

[Yugen-biki]

Very interesting!

What was the brand of the silicone you used? And what was it ment to be used for?

I made some white strobe a few weeks ago useing the formula on "United Nuclear", after I read about it on rec.pyrotechnics.
I made 20g just as a test. The Mg I used were not coated, and resulted in hyrdrogen gas development when H2O was added.
I think this effected the strobeing nature of the formula, because the star did not strobe, just twinkle/shimmer a little. But the lose powder behaved more like I'm used to think strobe behaves, when it was lit in a small pile.
It can be dangerous to use uncoated Mg! The issiue discussed on rec.pyro were the mixture heating up without warning. Worth thinking about.
Anyway, I piled all the star on a brick and lit them. The dark night were as bright as the day for a shot period of time.

[Creepin_pyro]

I piled all the star on a brick and lit them. The dark night were as bright as the day for a shot period of time.

Like this?

I used "Unibond" sealant. The Silicone is used as a waterproof sealant for bathrooms, windows, etc.

here it is at B&Q. Most hardware/DIY shops should sell it.

[Creepin_pyro]

These stars don't take fire as easily as I had thought. All the stars were blown blind from a perforated disk starmine. Any ideas about priming them, or will I be forever doomed to top-fused blue mines?

[dr thrust]

hmm , i love these old posts iam looking for interesting fountain comps, did this work in the end as a rocket fuel comp? may i ask what effect the silicone has, is it a fuel?