gomis Posted April 28, 2009 Posted April 28, 2009 Hi, Im preparing some color compositions using hexamine as fuel with no red gum. For stars ar ok, but for comets, in colors with less than 30% KCLO4, the burn rate is too slow, making the comet to come down. Im planning to change the hexamien content for red gum in order to speed the burn rate. My questions is Does anybody know if a composition with red gum burns faster than another one with hexamine? My compo type is as follows: KCLO4 +- 40%SrCarbonate +- 15Mg/Al +- 12Parlon +- 20Hexamine +-5DExtrin +-5
Seymour Posted April 29, 2009 Posted April 29, 2009 It will. Besides replacing hexamine with Red gum (they have different fuel values, consider that), you can... -Add a few % Charcoal-Reduce the parlon (with 15% Strontium carbonate, 10% will be plenty)-Increase the Magnalium content-Add a catalyst, like Iron oxide, Manganese dioxide, Potassium dichromate ect.
Mumbles Posted April 29, 2009 Posted April 29, 2009 Replacing the hexamine with redgum wont speed that up very much, it's the Parlon. Parlon is flame retardant. If you have it, try Saran at 15%, and increase the perc up to 45%. You could probably drop the SrCO3 back to 10% if it still isn't fast enough.
Fluorescein Posted April 29, 2009 Posted April 29, 2009 Hexamine is not very stable, so I ask myself if there are incompatibilities with pyrotechnical used chemicals beside acid containing sulfur.
Mumbles Posted April 29, 2009 Posted April 29, 2009 How exactly do you feel hexamine is not stable? And what sort of impact does this have on the subject at hand?
gomis Posted April 29, 2009 Author Posted April 29, 2009 What is the different fuel value between hexamine and red gum? Adding some charcoal for reds is ok. But for blues charcoal will disturb the blue color production. Can be replaced 5 parts of hexamine for 5 parts of red gum?
Fluorescein Posted April 29, 2009 Posted April 29, 2009 I mean that the chemical resistance of hexamine is lower than other pyrotechnical used compounds because already low concentratet mineral acid create the accordant sal ammoniac and methanal.
Zmuro Posted May 5, 2009 Posted May 5, 2009 What could I expect if I replace red gum with hexamine in Conkling blue or Wilbur's blue? Can I expect a deeper color or bigger flame?
Seymour Posted May 6, 2009 Posted May 6, 2009 It's hard to know. Sometimes the hygroscopicity of Hexamine can cause problems, and if the composition burns close to the ideal temperature with Red Gum, adding a cooler fuel (read hexamine) may cause the CuCl molecules to be less active as emitters. On the other hand, there is a good possibility that it will expand the flame and/or deepen the colour. Do please try it! I'd be interested in the results, and I'm sure I'm not the only one. One more consideration, is that Potassium perchlorate and Red gum will have a larger resistance to being blown blind due to high speed than with Hexamine. Hopefully someone has a better answer than mine!
TYRONEEZEKIEL Posted May 6, 2009 Posted May 6, 2009 Zmuro, I wouldnt replace the red gum for hexamine since it can act as a binder as well as an auxillary fuel. Hexamine also creates a pretty large flame envelope which is very good for blues. Gomis. It is certainly the parlon. I honestly see no reason for 20% parlon in that comp.. That is certainly slowing the composition down. Carbonates always slow burn rates down, especially strontium. I have had numerous difficulties with strontium carbonate and parlon red stars.. they wouldnt light, or had to be under constant flame at least for me.
Seymour Posted May 7, 2009 Posted May 7, 2009 Zmuro, I wouldnt replace the red gum for hexamine since it can act as a binder as well as an auxillary fuel. Well, it can, but it's not great. I'd definitely bind the blue with Dextrin or Parlon.
TYRONEEZEKIEL Posted May 7, 2009 Posted May 7, 2009 definitely. red gum does not make as hard of stars as dextrin or parlon. but the fuel value of red gum is much higher than dextrin.
50AE Posted May 30, 2009 Posted May 30, 2009 (edited) Will be there a problem if I replace the hexamine with red gum in a go getter mix ? Instead of : Sr(NO3)2 : 50KClO4 : 5Mg : 13Parlon : 17Hexamine : 9Red gum : 3Boric acid : 3 This ? : Sr(NO3)2 : 50KClO4 : 5Mg : 13Parlon : 17Red gum : 12Boric acid : 3 Edit : Are the hexamine tablets for cooking pure enough to use in pyrotechnics ? Edited May 30, 2009 by 50AE
Pretty green flame Posted May 31, 2009 Posted May 31, 2009 Edit : Are the hexamine tablets for cooking pure enough to use in pyrotechnics ? Esbit tablets for example contain only a wax binder so you have to grind them up, dissolve the powder in water and filter away the wax, this should give you pretty pure Hexamine.
Arthur Posted May 31, 2009 Posted May 31, 2009 Both Polish chem suppliers will sell granular hexamine. It's hardly worth buying the tablets and purifying them.
50AE Posted May 31, 2009 Posted May 31, 2009 Because I found it in a chemical supplier for 2.50 euro/kg, but I also realized that I had tablets at home, so I wondered if it's worth buying a kilo, I'll not use it all.
Swede Posted May 31, 2009 Posted May 31, 2009 50AE, try some experiments. You can always mix up 10 grams of star and do a quick test with a star gun, varying only the RG & hexamine. As for your fuel tabs, I'd bet they'd work OK as-is, even with the binder. They're made to burn, after all. But again, small-scale first, in case it doesn't do what you want it to. One of my favorite pasttimes is to grab a passfire recipe and mix 10 to 20 grams, mold a few stars, and see what it does.
Miech Posted May 31, 2009 Posted May 31, 2009 Esbit works fine, even without purifying it. It burns so pure you can actually see the red part of the copper spectrum when used in an AP blue.
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