Picture of Making Rocket Fuel With Kitchen Chemistry!
Today we're doing some kitchen chemistry using common household items.  This is the type of cooking that gets me excited, because I'm experimenting with recipes for solid-state rocket fuel.
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Step 1: Watch The Video!

WARNING: This project should not be attempted without adult supervision and adequate training. Misuse, or careless use, of tools or projects may result in serious injury, death, and/or permanent damage to equipment and property.  Ignition of an incendiary or explosive material may not be legal in your area.  Use of this content is at your own risk.

Step 2: KNO3 and Sugar

Picture of KNO3 and Sugar
For this project, I wanted to use some kitchen chemistry and a few common household items to test out a few different methods for making rocket fuel.  This type of rocket fuel is commonly referred to as "R-Candy"

The main components of this composition are a brand of stump remover, which is 100% potassium nitrate (KNO3), and plain white table sugar.

In addition, I tried using different amounts of corn syrup and homemade rust powder.  The rust was made by mixing steel wool (like these scrubbing pads) and vinegar, then letting it rust out over the course of 1-2 weeks.

Step 3: Mix Intimately and Caramelize

Picture of Mix Intimately and Caramelize
When mixed together in ratios of 60% KNO3/40% Sugar by weight, and placed on medium heat, they melt into a creamy brown liquid. This is because the sugar caramelizes and absorbs the KNO3. The smell is similar to that of making candy, and that's why this is sometimes referred to as "Rocket Candy" or "R-Candy".

The mixture is volatile, and will violently ignite if brought in contact with a flame, so extreme caution needs to be used at this point.

When it's runny enough, it can be poured into a casing to cool down and solidify. I'm using these Mega-Block LEGOs. Watch out, it's hot!
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ryckmans_t2 years ago
Sorry, but isn't the point of an Instructable to give instructions? This entry would be much more interesting if actual data was provided, e.g. at least state the units of ratio ("weight" for KNO3/sugar only appeared in the comments, nothing for the rust).
The King of Random (author)  ryckmans_t2 years ago
If you read the whole instructable you would see that KNO3, Sugar and "weight" were actually all in the instructable, so I'm confused by your complaint.

For your convenience I added 1% to the statement about the rust.


when you say weight, would that be like if you used so many cups of KNO3 you would have to use so many cups of sugar?
That would be volume. Weight means how much they weigh on a scale. Eg. 1 lb of bricks vs 1 lb of feathers.
oh so if you had 1 pound of sugar you would need so many pounds of kno3?
seriously? they give you percentages. 40% sugar, 60% potassium nitrate. (stated in the video, and on page three) i dont mean to be rude but how hard is it to figure out four parts sugar to six parts stump remover? but, if you must, 1 lbs of sugar, equaling 40% of the weight, means the total weight is 2.5 lbs. which means 60% of the weight, stump remover, is 1.5 lbs.

just take the percentage of how much you are mixing. For example, if you are making 2 cups of r-candy, what is 40% of 2? 60% of 2?

عدي غالب

عدي غالب

Umm, he literally weighed it right in front of you. He used a kitchen scale and weighed it in grams. The percentage number was based on how many grams of each product were in each mix.

Corinbw1 month ago

along with the rust being added to the mixture, you could also add powdered aluminum so that you get the a thermite reaction that happens at the same time as the other one. This will probably burn hotter, but it might not burn faster, you should give that a try though

will do man

TristanM51 month ago

omg it works i did it

Nemweb2 months ago

What about using the KNO3 itself? Pure KNO3?

VipinY2 months ago

what if i dont have KmNO4

could i use an electric model rocket starter to start it rather than a blowtorch?

TomT62 months ago

could this be used as an actual rocket boster on a real life scale?

TomT62 months ago

could this be used as an actual rocket boster on a real life scale?

Hey instead of a electric burner , can i caramelize the mixture over a gas flame in saucepan ? Is it dangerous or will it do ?

yes very dangerous to use gas flame.

aesquivel3 months ago

Another (dumb) question: KNO3 by itself is not flammable (as far as I know) and sugar isn't either so why are they flammable only by mixing them? do they react chemically even if they are not diluted? (sorry, I didn't pay attention in HS chemistry)

Sugar is flammable, and acts as the fuel. The KNO3 acts as the oxidizer and provides the oxygen needed to combust quickly.

aesquivel3 months ago

I saw your other video where you use 3/4" Schedule 40 PVC pipe, would a bigger pipe also work and may be able to sustain a heavier payload or 3/4 is the best option?

pyrobossVII12 months ago
how long does it burn? I'd like to put it on an airplane. literary every thing I find needs to be put on a model aircraft.

Depends on your mixture. Make it and time how long it burns.

joshadkisson made it!4 months ago
I made a sugar rocket, but I didn't have to carmelize my fuel, I simply used a 1" pvc pipe, powdered kitty litter for the nozzle, and a 60%/40% mixture of KNO3/powdered sugar. I even mixed in magnesium shavings for spectacular flare!

good indestructible for fuel testing though, I like the use of Legos.
ajp44 months ago

Do you need to wear a mask when caramelizing them?

shadowop5556 months ago

that is AWESOME!!!

does this make toxic gas when its carmalised
Fission Chips7 months ago

Upon making this with a friend, we were both ecstatic to see it shoot high up into the air! Great Instructable. I love your videos!

SebiA7 months ago

Hey Grant! I love all your experiments! Keep impressing me please!

SebiA7 months ago

Hey Grant! I love all your experiments! Keep impressing me please!

huddleto9 months ago

I have about 30 cedar tree stumps to get rid of. I tried salt peter and sugar but it just blew the stick I used to plug hole with about 20 feet in the air. Any suggestions?

patbking1 year ago

is there a substitute for KNO3


-JMS-1 year ago

Is it possible for u to make a rocket fuel without KNO3? Use I g only kitchen items?

Step 1: Get Hydrogen Peroxide. Step 2: Distill the Hydrogen Peroxide. Step 3: Add silver dust to start the combustion. Note: this is liquid fuel and it will be harder to use but a lot more efficient

lilchumy1 year ago
I love all your ideas! I hope to someday be as good at engineering as you. I recently made a pvc air gun. it uses an old air pump, a ball valve and some pvc. but it leaks air around the pump, ive tried hot glue, liquid nail glue, and several super glue. im stumped and cant find a good adhesive. what should I use? please respond.

get plumbing tape for round the thread
it stops water from seeping so should work

Tire patch glue and an old inner tube from a bike tire. The glue used to patch tires actually melts/partially dissolves the rubber of the tire and the patch. When it dries the melted rubber is fused with the melted patch.
-Good luck, I have made many spud guns using compressed air, they are really fun.

-Safety WARNING: the glue used (any glue that smells vaguely like clear plastic model glue) needs to be used in a well ventilated area. If you are not careful can cause very serious health problems. If you are skeptical, look up solvent vapour poisoning...
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