TheCircle Posted June 15, 2007 Posted June 15, 2007 I recently wanted to make stars with the following formula: Potassium perchlorate.........70Strontium carbonate............15Red gum............................9Charcoal.............................2Dextrin...............................4 I have no red gum and unfortunately no way of obtaining it in the near future, so I tried small batches of cut stars, replacing the 9% red gum with other chemicals. In some I replaced it with 3% airfloat charcoal and 6% dextrin, some with 8% charcoal and 1% dextrin, and some with 9% sucrose. I wet them with 40/60 ethanol/water, and let them dry indoors for several days. None of these stars worked. The sucrose ones burned very slowly with a pink flame on the ground, and I could not get them to light firing from a tube with BP, even with a hot Al/perc based prime. They also leave a lump of black solid after burning in ground tests. The others jet out orange sparks when lit on the ground, have no red/pink flame (or flame at all really), and leave a large mass of grey solid. In the air they appear to do the same. Interestingly, the burning stars turn the lighter's gas flame red when it is held next to them, especially with the ones that jet orange sparks. My question is, is there a way to get these stars to work without red gum? I assume the red gum is there as a fuel/regulator more than a binder, because of the dextrin. I'm somewhat limited with chemicals, but want to make colored stars for the 4th. Is there a better red star formula out there I can use? (list of what I don't have: Cl donors, KClO3, ammonium perc, strontium nitrate, magnesium) Thanks a lot for any help or suggestions.
itwasntme Posted June 15, 2007 Posted June 15, 2007 I have tried a dangerous, and stupid formula, but it does work. 10 road flare mix, that is screened to remove large pieces of wood5 600 aluminum, spherical Its a bit hard to light, so I primed with some green mix, that had some zinc and aluminum in it. I pumped with 1/4 inch pump.It kinda strobes somewhat, and is extremely bright, even 400 feet in the air.
DeAdFX Posted June 15, 2007 Posted June 15, 2007 I use hexamine as a subsitute for red gum. Hexamine is fairly slow burning compared to other organic fuels. If you don't have hex then I don't know what will make a descent subsitute. Before taking a quiting pyro(damn neighbor) I was trying a benzoate color system. You could try using Strontium Benzoate or Strontium Salicylicate in place of the carbonate. Try something like this KClO4 70Strontium benzoate/Sally 15Charcoal 2-5Sulfur 0-6 Dextrin 4 The sulfur and added charcoal will help with ignition. If you don't like sparks in your comp then you can remove all of the charcoal and replace it with sulfur.
al93535 Posted June 16, 2007 Posted June 16, 2007 Too much oxidizer. The red gum is simply a fuel in this use. Reduce the KClO4 to about 60% Sr carbonate 17% Charcoal 4% Dextrin 4% The remaining 15% should be any organic fuel and a chlorine donor. Of course red gum with some 200 - 300 mesh metal powder would be ideal. But you can also use sucrose, lactose ect... Be aware Sucrose is hygrosopic, and could be why you had no ignition. However it looks like your only option. Like mentioned above hexamine would be an excellent choice of fuels. It can be obtained from camping/sporting goods stores as fuel pellets and will need to be crushed. Also without any chlorine donors your colors will be weak, and about the only half ok color you might get will be red. Is your charcoal finely powdered? I suspect thats where you are getting the orange sparks from.
TheCircle Posted June 16, 2007 Author Posted June 16, 2007 Thanks for the advice - I'll try to find some hexamine fuel tablets today. I was using airfloat charcoal, so that's almost definitely the source of the orange sparks. I guess the lack of a visible flame was because of fuel deficiency, and the solid mass maybe KCl or some other product of oxidizer decomposition. As for a chlorine donor, I read on here about the use of Sculpey modeling clay as an alternative chlorine donor for people who don't have Parlon, PVC, etc. I might try that as well. I tried PVC glue, but the THF/MEK/Cyclohexane fumes from it were a little much for me without a proper fume hood.
Mumbles Posted June 17, 2007 Posted June 17, 2007 If you can find it, Shellac is generally a 1:1 replacement for red gum. It may mess with the color a bit pushing it to more pink, but you never know until you try. Try to find the solid. If you can only get the solution of it, you could probably just bind the stars with it.
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