Step 4: Cooking Process

Put the pot onto a stove and set it to about 150 Celsius while stirring constantly to dissolve the KNO3 and Sugar.
Before the "Crystal Mush" stage Do not use gloves! It may soak up and Ignite, case in point fusepaper...
Once all the solids have dissolved you can turn the heat up a bit.

Tip: if the solution starts bubbling up a lot simply turn down the heat and be patient.

Eventually there will be a red slop and once it starts having the texture more viscous than water this as James Yawn says the "Crystal Mush" stage now turn down the heat to 125 Celsius and put Gloves on.
Once you have passed this stage make sure you mix and stir the propellant a lot because it reduces bubbles of air making it more durable once done.
When it starts looking a bit like putty turn the heat down to 107 Celsius and continue to cook, if you still hear sizzling then there is still water in it.
Once the sizzling has stopped you can take out a small piece the size of a pea and roll it with your fingers.

Tip: Make sure that the Rcandy is covered by something while you are off doing other things so that if it does ignite there will be less damage.

If it feels sticky that's the moisture in it so continue cooking, if its easily roll-able and not sticky mash it flat and let it cool. Once cool bend it and see if it snaps if it bends then keep cooking the rest of it and do another test in a few minutes if it snaps and is brittle then it is ready for moulding and the Rcandy has finished cooking.
-Remember that the propellant is very Hygroscopic so it likes to suck up water from the air, I did a rocket that was supposed to have a burn time of 0.2 seconds and it went for 15 so keep it dry.


What if you have a gas stove and cant set the temperature? Is there different instructions?
I would not recommend using a gas stove since this is a form of rocket fuel which is highly flammable and any chance of ignition is a severe danger. If you really wanted to use a gas stove you could perhaps use a oil bath but still I wouldn't reccomend it.
Does anyone know how to make rocket motor casings? I have read many comments that hint that I can make them using stiff paper but I have not found a detailed description of how to make them. I also have had trouble finding ways to make rocket nozzles.
Look at my instructable for making roman candles, it shows a procedure that produces good motor tubing. Alternatively you could just buy some tube.
You can also flick a tadbit of water onto the mixture to see if there is any water left. If it immediatley turns to steam, you know that the mixture is above boiling point, and it is not bubbling, therefore there is no water.
That would seem logical
I have done it, seems to work.
What would you suggest i use as a rocket fuel: Should i use BP in the traditional 'rammed' method, or this r-candy? Which fuel with make the same sized rocket fly highest?
There are plenty of pros and cons for Rcandy; Rcandy Pros -small amount of slag -easily made -relatively safe Rcandy Cons -Not as high a specific impulse than BP (I think) -Fractures in the grain are more prominant -Hygroscopic and to answer your question, a BP rocket would fly higher but I think it wouldn't be worth the trouble
Thanks alot, im gonna give rcandy a try and see the difference in performance for myself. Oh,sorry for the slow reply, i thought i allready had.
you dont have to have iron oxide
Yes the Iron Oxide is an optional catalyst that increases the burn rate by 50% That said, Ive never tried it without it so the results will be variable
Question, I tried to change this up by dissolving the salt peter in 91% rubbing alcohol then mixing it with molten sugar, the first time I did this The salt peter was in little balls about one millimeter in diameter and I mixed the sugar and salt peter first then added alcohol in small bits, this dissolved the saltpeter(I saw the balls disappear), however when I heated the alcohol to boiling using a hot water bath the saltpeter did not really dissolve in the the alcohol very much, why was that.?
The properties of different solvents can vary, Ethanol (CH3CH2OH) which I think is the main ingredient in rubbing alchohol. This can dissolve some solids and not others, depending on their polarity ect... KNO3 and sucrose dissolve very well in water (all nitrates dissolve in water) But CuCl dissolves in Ethanol and NaCl doesn't, so I have no idea :( btw the little pellets are known as "prills"
I find it quite interesting that the stoichiometry in your 'ible is explained much better than my chemistry teacher might have put it.
Thanx man, my chem teacher is nice but not so good either. At the moment we are learning about atomic structure and covalent bonding :) How condescending...
if I don't add any iron to the mixture will I get drastically different results
The reaction rate will be eccentialy divided by 2.5 If you do It just means rockets ect will need to be designed differently to incorporate the slower burn rate I suppose it would work with the roman candles, but ive never used it :P
Looks good. Does the iron also make it burn a certain color?
No, the Iron oxide acts as a catalyst only
Have you tried alcohol instead of sugar. I tried a one to one ratio of sugar to saltpeter melted the sugar and added alcohol to dissolve the saltpeter. the alcohol was boiling but did the job and that way I could form it while it was still wet and not have to what for it to dry completely. Granted the first time it caught fire but the second time it worked great.
Yes I have been pondering using 50% Methalated spirits 50% water for cooking because it would evapourate much easier... But the flammability danger is greatly increased because of the ethanol, and the water method works fine for me. As a fuel I strongly suggest against it, Ethanol Is a liquid and it will make a composition similar to ANFO! P.S. August 2 my BIRTHDAY!
cool g im new can u send me 1 of ur eseys resipes in ml so i gan get it good
This is as simple as I'm going to make it, if you don't understand it study the concepts expressed and learn some chemistry. This page is not about making bombs its about science.
When I did it I was using 91% rubbing alcohol. And although the alcohol itself is flammable the boiling of the alcohol kept the reaction under the flash point. the first time it caught fire when we were trying to boil the last bit of it off. In short as long as you keep it in a well ventilated room so the the vapors don't catch it doesn't seem to spontaneously combusted when using alcohol. P.S. A. what is ANFO and how ethanol make it like the it, and B. does a fire extinguisher work on this type of fire since it has it's own oxygen supply. I know water works but I figured that was because it lowerd the temp of the fire.
ANFO stands for Ammonium Nitrate Fuel Oil and is a mix of 95% NH4NO3 and 5% diesel fuel, it has had much media attention due to its use in terrorism...<br/><a rel="nofollow" href="http://en.wikipedia.org/wiki/ANFO">http://en.wikipedia.org/wiki/ANFO</a><br/>And the reason it could act like ANFO is because it is in the end fairly similar (a solid oxidiser and liquid fuel)<br/>I don't actualy know!<br/>Water and CO2 definately work, dry powder should as well.<br/>
I think someone misunderstood someone. I was not sugesting using the alchol as the fuel. I was sugesting using it to combine the sugare and salt peter. I usualy boil of most of the alchol. but this way if I don't boil it all off the disoving agent will help not hinder the reaction.
Yeah I guess so... Its just if it does catch fire during the process its very dangerous
how come you don't have this on pdf??
you can also try making golden powder if you risk using the oven for this method. 60 grams kno3 to 40 grams ascorbic acid (vitamin c). search youtube :)
That looks very similar to well refine flash candy, and it seems easier to make. I wonder if anyone has recrystalised it? It would be very dangerous then What on average is its sensitivity? (in joules)
I can't find Kno3 any where!!!!!!!!!11
Where on the planet are you located?
I live in the U.S.A. Oh, if you wondered i changed my name.Where do you get your Kno3?
Have a read of the instructable a bit closer, It explains everything...
Did you get this idea from James Yawn?
Read it then comment; "I would like to acknowledge James Yawn for not just his inspiration but his process in which this instructable is a hybrid."
I'm sure that flash candy does not quite make a fire ball like that.
No, thats an atomic bomb.<br/>But flash candy burns similar to gunpowder just 5x the smoke, so 100g = 2 meter flame and a 4 meter diameter mushroom cloud.<br/>
By the way I made anew instructable:<br/><a href="http://www.instructables.com/id/How-to-make-a-Rcandy-Roman-candle-firework/">http://www.instructables.com/id/How-to-make-a-Rcandy-Roman-candle-firework/</a><br/>
Although currently there is very little reason to make RCandy I will eventually add some more Instructables such as; How to make a Rcandy Roman candle How to make a cherry bomb General smoke bomb ideas (including pull ring smoke grenade which is awesome) (if my prototype goes successfully) how to make a rocket firework Please leave a comment as constructive criticism is much obliged.
You listed sucrose as a replacement for both sugar and iron oxide when iron oxide is not available, but sucrose is just another form of sugar, and it's the same with Karo Syrup, so why can this not be performed with just sugar, Potassium Nitrate, and water. If I'm mistaken, please correct me.
It can be performed with only KNO3 and sugar:<br/>65g KNO3<br/>35g Sucrose<br/>40ml Hot Water<br/>The karo syrup (or honey) is a mixture of sugars including dextrose (binder/fuel) and glucose (fuel) doesn't support a flame if mixed 1:1 with KNO3, so icing sugar (sucrose) is used with some karo syrup oddly making a faster reaction.<br/>The Iron Oxide is an optional catalyst meaning it is not involved in the chemical reaction or if so it comes out of the reaction as iron oxide...<br/><a rel="nofollow" href="http://en.wikipedia.org/wiki/Catalyst">http://en.wikipedia.org/wiki/Catalyst</a><br/>PS if you decide not to use Iron Oxide it not outweighed by the negatives, IT STAINS LIKE HELL<br/>
Thank you, I definitely want to try this out. Out of curiosity, have you ever tried making a hybrid motor? My old school had a research and development program and it was amazing how many things could be used as a fuel when used with an oxidizer. One of the most impressive(partly because it was so cheap) fuels we tested was roofing tar.
By hyrbrid do you mean non solid fiel and oxidiser? I have made a few rocket motors but only James Yawn's rocket motor design works well! The attached image is the laMda Rocket (M is capatalised because my friend though it was an N) Ufortunately it was a failure... If you want to make some RCandy do some burn rate test of about 5mm diameter "rod" and send in the results!

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Bio: "But I being poor have only my dreams, spread out beneath your feet. Tread softly because you tread on my dreams" 1st Cleric Preston, Equilibrium ... More »
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