Simple Solid Propellant Question

Greetings,
I have a simple propellant question. I have not seen references to this particular mixture, so I'm curious both for the chemistry and
safety.
A melted mixture ( kids, don't try this at home !! ) of potassium nitrate, sugar, and sulfur - burns reasonably well, but not well enough. Granted there is a difference, in a given reaction, between the carbon released from sugar and the carbon available in powdered charcoal, I have noticed that the same sugar / KNO3 / sulfer mixture burns much faster when modified to include 1% powdered charcoal.
Is the charcoal acting as a catalyst? - and if so how.
Could the addition of charcoal lower the effective auto-ignition temperature of the mix ?
Could it be any more dangerous to make ?
Interesting feedback would be appreciated.
Cursory cautionary note; Propellant making is interesting, but cannot be done safely without taking every precaution. It's not possible, really, to take every precaution, so don't make propellants .. besides it's tedious and you'll rarely launch anything.
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Blahblahblahblahblahblah wrote:

LOL!
Too true!
-dave w
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It's not possible,

I could not disagree more. It's not tedious, it's fun. As for "taking every precaution", that's not possible in anything. Hell, getting out of bed is hazardous. Breathing is hazardous. Ever drive or ride in a car? Talk about dangerous... This is similar to the idjits that say you won't save money by making your own motors. That's hogwash. When was the last time you bought a K motor for twenty bucks? Or an M for a hundred? Takes me an hour and a half to cast three 98mm grains. That's an M motor. Takes longer to properly prep the rocket. Last EX launch, I put up four flights personally, flying J through M power, and "loaned out" five other motors, ranging from I impulse to a large L. (No, I didn't sell them. I was offered some cash to offset the cost of making the propellant, but refused it. I like to showcase my motors. I received a lot of compliments, and not from only the people flying them...) Please don't tell me not to make propellant... If no one ever experimented with propellant, we would not have a hobby in rocketry...
RY
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I took it as a standard disclaimer.
Mike Fisher
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The charcoal is doing several things 1) Its reaction temperature is higher, since all of it reacts and no water (requiring hear to vaporize and expand it) is released. Higher temperature leads to higher burning rate.
2) It is black, and absorbs more energy on the propellant surface from the flame than the rest of the stuff does
3) It makes the melted propellant less flowing, and causes more voids during casting, making the resultant propellant more likely to cause explosions on the launch pad.
The sulfur lowers the ignition temperature of the propellant, making it a lot more likely that it will ignite in your face. I appreciate your intention to be safe, but I respectfully suggest that what you are doing may be more dangerous than you appreciate.
Not to say that rocket propellants cannot be made safely. It is hard to learn to make them safely by yourself, though. It is even harder to do so legally.
Luck and Regards, -Larry Curcio

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following up on my own post;
To the rocket motor maker, of course it's fun (and still tedious at times) to make rocket motors, I think that people who post on this topic ought to be careful with recipies and so forth, as we have a responsibility to protect children and the not-so-clever from injuring themselves. A few words of caution belongs with anything that could cause harm.
I would think though, that perhaps Americans should be doubly advised to not make rockets, as both the culture and election results clearly show certain hard limits on mental faculties.
The powdered charcoal appears to be a good means to modulate the burn rate of sugar fuels, and I will be experimenting with it further near the 1% level. I could see from my few tests that charcoal could turn your core-burning sugar recipe into a mix that burns fast enough to split the motor casing. The other danger could be the potential burn rate of the heated mixture while melting. I would imagine scorching hot molten mix would not make a good face mask, especially if it was burning as well.
-geoffgallo
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On 22 Nov 2004 06:43:42 -0800, snipped-for-privacy@yahoo.com (Blahblahblahblahblahblah) wrote:

Ok. So why didn't to specify what country you wanted your answers to originate from? Should they come from whatever country you are from?
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