27 replies to this topic

[NightHawkInLight]

This mix makes a very deep outstanding purple, I made it in an unsuccessful attempt to obtain a blue from copper chloride. It does quite well without Al or Mg to brighten it.

Here's the composition:

Ammonium perchlorate - 70
Charcoal - 15
Sulfur - 8
Copper(II) chloride - 7
Dextrin - +5

All components withholding the AP are milled until a fine powder is reached. Once done, the AP is screened in provided it is already a fine powder, otherwise it also may need some milling. The mixture can be dampened and pressed into tubes as a traditional go-getter.

A secondary 'tubeless' method I have found to work is to dampen the mix further than would be standard so it is the consistency of a thick caramel. The mix is then dripped onto wax paper so it makes 'Hershey's Kiss' shaped stars about the size of a penny. They seem to ignite well without prime for about a week and then will fail to ignite. I plan on testing a way of priming the Hershey's kiss type stars next week by dipping half of the dry star in nitrocellulose and then quickly from there into BP.

Here is a video to show how they preform out of a mine in the Hershey's kiss style. (sorry, it's in daylight so you can't see the color)



Next time I am using these stars I will try to record a better nighttime video. It's a hard color for the camera to pick up, it makes them appear white.

[DeAdFX]

If this is any motivation please get a nighttime video ASAP!!!! I am curious as to how colorful the stars will loook.

[NightHawkInLight]

Well I have just uploaded a video of a ground test, a shell video hopefully in the near future. The video description describes everything:

[crazyboy25]

love the effect and color and i know someone who has copper (ll) chloride and no use for it but im put off by the short shelf life i have had a stroke of potential genius when i was making whistle mix (with Vaseline and lacquer thinner) i lit one of the small clumps it burnt a very nice yellow due to the sodium benzoate and it shot around maybe if i pump whistle mix while it is wet then roll it in BP it will create a longer lasting yellow self propelled star. what do you think?


BTW: consider using a non water based primer like NC lacquer or shellac to prevent copper (ll) chloride degredation.

[NightHawkInLight]

The whistle mix idea sounds good to me, I don't know what a suitable binder would be. It seems like something that would also not be very visible, although with a whole swarm of whistle mix stars it might look alright.

I did not know that copper (II) chloride had a low shelf life, does it actually decompose or is it merely hygroscopic? I have not yet tried another batch since the one in that video in my above post, I figured for the next one I would simply dry the chloride out in my fireworks dedicated toaster oven.

I am planning on firing a shell filled with these stars and a fast burning chrysanthemum of mystery type mix in the next week. Unfortunately the go-getter effect will most likely not preform very well until I make another better milled batch.

[Mumbles]

You could add some metal to it. I remember seeing a star comp that was essentially whistle with FeTi in it. It should still jet around.

As far as the stars go. CuCl2 is stable enough, but is just hygroscopic. CuCl does however have a limited shelf life. I imagine it is the CuCl2 that causes the comp to degrade so rapidly. It likely forms NH4Cl, which absorbs water and will overall hurt the burn rate. It may also just be CuCl2 absorbing water. If someone else would like to try it, I'd suggest some copper oxychloride instead for better stability.

In the shell, they might be a bit of an odd combination with chrys of mystery. It's not a color issue, but rather a preformance issue. To me, go getter shells look better broken softly, like a poka shell, and letting them run around. To hard, and they don't swim as much. Chrys of mystery is the exact opposite. As the name implies, it is designed to be broken like a chrysanthemum, which is relatively hard so it forms long straight ropes of sparks.

Just one thing I was wondering about. Do you think this effect is from the comp itself, or way they were formed. It will be a pretty energetic comp I will give you that. However, the effect may be due more to the fact that it's burning unevenly.

[crazyboy25]

You could add some metal to it.  I remember seeing a star comp that was essentially whistle with FeTi in it.  It should still jet around. 

the metal sounds good im thinking 10% but what should i use i have:

-325 mesh atomized aluminum
-325 mesh MgAl
3 micron dark flake Al
granular Al

[Mumbles]

The first 3 are definatly too fine if you want a real tail. The granular Al, would be the best best for a tail. If you just want it to show up, any of them would work, but I'd suggest whatever is cheapest. My personal preference would go to -325 mesh atomized Al.

[NightHawkInLight]

As far as the stars go.  CuCl2 is stable enough, but is just hygroscopic.  CuCl does however have a limited shelf life.  I imagine it is the CuCl2 that causes the comp to degrade so rapidly.  It likely forms NH4Cl, which absorbs water and will overall hurt the burn rate.  It may also just be CuCl2 absorbing water.  If someone else would like to try it, I'd suggest some copper oxychloride instead for better stability. 

In the shell, they might be a bit of an odd combination with chrys of mystery.  It's not a color issue, but rather a preformance issue.  To me, go getter shells look better broken softly, like a poka shell, and letting them run around.  To hard, and they don't swim as much.  Chrys of mystery is the exact opposite.  As the name implies, it is designed to be broken like a chrysanthemum, which is relatively hard so it forms long straight ropes of sparks. 

Just one thing I was wondering about.  Do you think this effect is from the comp itself, or way they were formed.  It will be a pretty energetic comp I will give you that.  However, the effect may be due more to the fact that it's burning unevenly.

Regarding the degradation of the composition, I think it is merely the hygroscopic nature of the CuCl2. I was unaware of that and so I took no precautions to seal the stars into anything airtight. They still burned fine after several weeks, however they would not ignite from a break. If it were a chemical reaction taking place to form NH4Cl I would think the burn rate and color would be negatively effected.

Your point about the chrysanthemum stars in with the go-getters is valid, however because of the damp CuCl2 forcing me to reduce my milling time significantly I doubt this batch will preform as go-getters at all. They will most likely just end up as purple stars. Another shell will be needed with the properly made stars once I dry my CuCl2 out to see how they really preform.

Your last comment on the mix about the uneven burn is also correct. Were the burn completely even I suppose any star would stay along its flight path from the shell. (simple physics in action, equal force from all directions results in no change in motion) That is why I had the idea to only dip half of the star in NC and then BP to prime it. So it is an uneven burn, but intentionally so. I have to admit I have posted this composition before I have used it in any larger shells, so we shall see if the stars are bright enough to be attractive when only one side is ignited. I have used them in smaller 1.5" shells, but the effect is different that close to the ground no doubt.

One final note, I once made a small batch of this comp and replaced the copper chloride with copper sulfide. It yielded a similar result. I did not think twice about it because I did not realize that the chloride was hygroscopic, maybe copper sulfide is a replace that could be used to make the stars keep longer. Also when Mg is added to the sulfide comp, it makes a glitter that at first glance looks like winokur 20. No other tests have yet been done.

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Well I have fired the shell I was preparing. The spolette failed to ignite on the first fire, so I attempted to fire it again and it caused a pot. At least it was a good video of the stars at night. They got a little propulsion, but would have done much better were it a better milled mix.



I'll try to get a new shell up in a few days. I still have enough stars for another shell, but I'm out of BP and hulls.

[deadman]

What a difference in color than my "purple" I can't even remember the comp I found, but it was still a bright blue not even close to purple. I really enjoyed that. Would this be energetic enough to work as a driver propellant?

[NightHawkInLight]

Certainly it would be. I have only tried one rocket with it out of curiosity. It was a 1/2" ID endburner and it CATO'd. I only tried the one time, but I'm sure it would work with some nozzle adjustments. It is made with ammonium perchlorate after all.

[crazyboy25]

just tried my yellow self propelled stars these were without metal pumped 1/2" and they worked well this was the second one the first one lit way faster and shot around at the end like a piece of visco. http://s179.photobuc...nt=100_0863.flv

i should have videos in the air very soon.

[NightHawkInLight]

Hard to see through the smoke and light flooding from the camera. It looked as if that mix put off the full 'campfire' like flames similar to poorly made candy propellant burned in the open. I think they need to be seen from farther away and at night to really tell how they look.

Of course a mine or shell would be best so you can detect just how much movement they get.

[deadman]

If you're going to do mine make sure to get it on vid for us.. I couldn't imagine setting off a mine like nighthawks around people, but I loved watching the video.

[tentacles]

You could add some metal to it. I remember seeing a star comp that was essentially whistle with FeTi in it. It should still jet around.

As far as the stars go. CuCl2 is stable enough, but is just hygroscopic. CuCl does however have a limited shelf life. I imagine it is the CuCl2 that causes the comp to degrade so rapidly. It likely forms NH4Cl, which absorbs water and will overall hurt the burn rate. It may also just be CuCl2 absorbing water. If someone else would like to try it, I'd suggest some copper oxychloride instead for better stability.

In the shell, they might be a bit of an odd combination with chrys of mystery. It's not a color issue, but rather a preformance issue. To me, go getter shells look better broken softly, like a poka shell, and letting them run around. To hard, and they don't swim as much. Chrys of mystery is the exact opposite. As the name implies, it is designed to be broken like a chrysanthemum, which is relatively hard so it forms long straight ropes of sparks.

Just one thing I was wondering about. Do you think this effect is from the comp itself, or way they were formed. It will be a pretty energetic comp I will give you that. However, the effect may be due more to the fact that it's burning unevenly.

If ammonium chloride is forming, then the copper perchlorate formed is also very hydroscopic. It also has a melting point of 130C. I'd been wondering if it was usable in a sealed pyro device, though.

[crazyboy25]

yeah i will test them in a star gun with less lift (.8g) as soon as i can (im worried people will become scared because people are paranoid about the fires here)

[NightHawkInLight]

Copper perchlorate...What a great oxidizer that would be for blues and greens if the hygroscopic nature could be brought under control. Used in union with ammonium or potassium perchlorate that could have some potential. An efficient and easy synthesis would be needed for me to trouble with it though. Not to mention I have no idea about sensitivity and incompatibility.

Crazyboy25, I'm looking forward to seeing your tests. Be sure the area is especially wet before trying anything though...Go getters aren't the most predictable things for ground use. I wouldn't try anything besides a high rising shell if it hadn't rained in a while.

[Wyvern]

Maybe if you bound it in NC and stored them in shrink wrapping you couls get round it.

[NightHawkInLight]

I would think a heavy binding with NC would severely reduce water absorption for anything hygroscopic. The only downside I can see is the stars may have a short time where they are yellow before bursting into color, and perhaps an increase in sensitivity. Even so, it's not to bad of a problem.

As far as my go getters go, I'm still waiting on a chance to dry out my copper chloride and mill up a new batch. I'd really like to show how they preform when properly made.

I may try another test next week and attempt a colored glitter out of this comp with the copper sulfide replacement and added Mg.

[Mumbles]

You're definatly going to need metals for any shot at a colored glitter.