permiatesubstrate
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Rocket Candy Problem Discussion
I've come across a few problems, maybe someone with experience could enlighten me. I should mention that i've combed the internet, and this site, for
an answer to the following problem but found nothing.
KNO3 99% pure
Powdered sugar
Mixed in a 66:33 ratio (by volume) with water, mixed and heated, reduced until only a white powder remained.
When lit, the mixture tends to melt as it burns and create a protective layer of char that hinders the reaction.
When lit outside of a tube (as just a ball) it only melts and burns where flame contacts it, it is unable to sustain a reaction.
Those two problems have pretty much halted any progress.
I've noticed both problems tend to occur when I use KNO3. I tried making a fuse by supersaturating jute twine with KNO3 and all it produced sparks but
also bubbled. The reaction sustained poorly and could not travel through a hole as a fuse should.
Any insight will be appreciated.
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497
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The water added probably did it.. Just carefully stir your KNO3 into melted granulated sugar. Obviously it will ignite if overheated too much. But its
not too tough. I promise it will work.
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Bot0nist
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The water trick does work well to get the mix evenly dispersed. You just didn't bring it along far enough. Sounds like the sugar and
KNO<sub>3</sub> just recrystallized out of a rapidly evaporated solution. You need to heat the mix a little past this point, while
stirring as the KNO<sub>3</sub> melts as well as the sugar. Keep heating gently until you see a light caramelizing of the sugar. Not
brown, or even tan.. Watch it close. Then cast or cool and pulverize.
Also, you can play with the ratios to favor speed/thrust to smoke. Also, if it packed into a tube (rocket) it may need to be cored.
[Edited on 6-7-2011 by Bot0nist]
U.T.F.S.E. and learn the joys of autodidacticism!
Don't judge each day only by the harvest you reap, but also by the seeds you sow.
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Morgan
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Powdered sugar has 3% cornstarch to prevent caking. I don't know if that matters much, but perhaps pure sugar would be best. Also, when you are
melting the sugar and KNO3, be sure not to ever put your face over the mixture. Being very hot, it can go off in a near flash. Melting sugar and KNO3
requires some caution. If you get one spot on the pot or pan just a bit too hot, the game is over. As mentioned, it should turn a caramel color.
I remember lighting pea-sized bits of the hardened fuel and they would spin up and take off, whizzing around in the air erractically until burning up
into nothingness. It was kind of exciting to avoid them as they flew around every which way.
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Bot0nist
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Quote: Originally posted by Morgan  | | Also, when you are melting the sugar and KNO3, be sure not to ever put your face over the mixture. Being very hot, it can go off in a near flash.
Melting sugar and KNO3 requires some caution. If you get one spot on the pot or pan just a bit too hot, the game is over. |
You got that right man! I were a face shield though. I don't care if I look like a dork. Facial burn scars look worse.
Using low heat and just stirring the whole time thoroughly helps your chances a lot. Also, if you notice any spots starting to darken near the bottom
of the container, remove it from the heat source and dip the bottom of the beaker/pan into some cool water to quickly cool it.
Its better to make 3 small batches than one big one as well.
[Edited on 6-7-2011 by Bot0nist]
U.T.F.S.E. and learn the joys of autodidacticism!
Don't judge each day only by the harvest you reap, but also by the seeds you sow.
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497
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| Quote: | | Melting sugar and KNO3 requires some caution. If you get one spot on the pot or pan just a bit too hot, the game is over. |
If you melt all the sugar first slowly, and gradually stir in the KNO3 using a relatively thick pan its pretty tough to screw up. And you can see it
get darker and bubble in spots before it actually ignites.
Or you could just use an oil bath at the right temperature and not have to worry about it..
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gregkdc
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Your problem is that you are using volume. Just re-do your experiment and use gram instead.
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nitro-genes
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The master at work: --> http://www.youtube.com/watch?v=quj1XKq8Enk
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watson.fawkes
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He's using Karo syrup as part of the sugar. This is an old
trick in making confections; the effect is to lower the average crystal size, making for a smoother mouth feel. Here it seems to improve the
workability of the propellant. Clever.
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Morgan
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Probably not good to breathe but otherwise ...
"Alien" R-Candy-Cooking Method
http://www.youtube.com/watch?v=XVKvlX2W_-g
http://www.health-report.co.uk/ethylene_glycol_propylene_gly...
http://www.buzzle.com/articles/propylene-glycol-dangers.html
http://www.buychemicalsdirect.com/Propylene-Glycol-Dangers-s...
[Edited on 7-7-2011 by Morgan]
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Fusionfire
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Nice. Open flame heating, indoors, shiny kitchen + cooker, no gloves while heating, pouring fuel into frying pan near an open flame...and a wedding
ring.
Can't get any safer than that
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Morgan
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Yes, all good points there Fusionfire. I used to say never grind more than you want to blow up in your face, but I suppose you could alter the adage
to fit rocket candy too.
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