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.


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

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

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!

Step 4: Variations

I tried some more batches with other ingredients added, like water, corn syrup and even tested a little home made rust powder (Iron Oxide - about 1%).

All the fuels burned a little differently, but overall I was most impressed with the batches using the homemade rust.

To see the burn tests, you can watch the video here.

Step 5: The Best Batch

I made another batch and packed it into a homemade rocket motor casing that had a nozzle made from kitty litter. I was impressed to see it actually worked! I think this rocket shot up a couple thousand feet.

If you haven't see the video yet, it's not too late.  Watch it here!

If you like this project perhaps you'll like some of my others. Check them out at www.thekingofrandom.com
Can u tell me how to make rocket fuel WITHOUT KNO3 please
Grind up charcoal (coffee <br>grinder works well) and mix it with a powdered oxidizer. Note: doesnt work as well
<p>kno3? What does that mean?</p>
<p>kno3 is potassium nitrate</p>
<p>Kno3 Is Potassium (K) Nitrate (No3)</p>
<p>i do not think thats possible. potassium nitrate is what helps burn</p>
<p>Dat Es Korract </p>
<p>You could use potassium perchlorate, potassium chlorate, sodium, sodium chlorate, or ammonium perchlorate. All of the chlorates-perchlorates are more powerful than potassium nitrate, and consequently more dangerous. You would also have to calculate the fuel-oxidizer ratio yourself.</p>
<p>Where could you get pure sodium?</p>
<p>eBay, Amazon, Lab chemical shops, I don't really know!</p>
<p>could i use ammonia nitrate?</p>
<p>Why? You may purchase Kno3 At Canadian tire as Spectracides Tree Stump remover.</p>
<p>Another easy to get oxidizer (at least in Poland) is potassium permanganate- KMno4. In my country you can buy small amounts at chemist's, but i'm pretty sure it's harder to get in most countries. It's much stronger oxidizer, however it leaves a lot of purple smoke that stains everything, and you have to calculate oxidizer:reducer ratio by yourself.</p>
<p>Well, you could use rubber as the fuel and nitrous oxide as the oxidizer, but you can't cook that up in your kitchen - you'd need a pretty serious shop</p>
<p>You need some kind of oxidiser to make your rocket go. Potassium nitrate is probably the easiest to get. It isn't available at stores where I live (in Australia), but I don't think it's illegal, and friends have been able to get some online. Other than KNO3, NASA, ESA, and Roskosmos mostly used liquid oxygen, which us probably not possible to get without arousing suspicion as to why you want it.</p>
its pretty easy to get... look in garden center or online <br>
<p>So the thing he used which contained KNO3, if I just go outside and buy KNO3 I can use the same concentration, right?</p>
<p>Stump remover (the thing he used) is pure KNO3. SO YES.</p>
<p>This is the coolest thing i have ever seen in my life!</p>
<p>My mom would like to make this for 2 reasons:</p><p>1-It's a cool science experiment,</p><p>2-(Here's the funny part) She says we have too many lego's.</p>
<p>smoke is not bad 4 u, ah, nothing like the smell of r candy in the morning!!</p><p>If you want more thrust add 1% red iron oxide, as it is a burn rate enhancer.</p><p>Do you research if your not sure, this is dangerous. If u don't know what ur doing, don't do it. Accidents are bad for u, and make us all look bad....</p>
Is the smoke it makes toxic. What I mean is, if you breath a little in by accident. Will it harm you a lot or a little or not much at all
<p>I breathed some in a while ago and had no ill effects, so I suppose it will not harm you at all</p>
I'm just curious,but if you in crease the amount of KNO3,will it burn faster,or will it go ballistic and explode,because that would be bad for me and my rocket
<p>Excess oxidizer will not increase burn rate, it will just melt and decompose, wasting costly potassium nitrate-Kn03</p>
<p>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?</p>
<p>Make some black powder and then pour it into a hole drilled in the stump and pour molten wax over it after inserting a fuse. This method can crack rocks.</p>
Use about a quarter pound mixture (114 grams) and add charcoal (about 20 grams will do) but this time do not plug the hole as that creates a small deflagration
If any Canadians have been able to get KNO3 r(legally) ecently as in this year,could you please post it. Like I said in my earlier post,it's been banned. Can't even get it in a garden centre.
Fun fact for any Canadians trying to do this project(I was going to). You can't get stump remover in Canada,it's been banned. I believe you have to have a special license to get it. Not actually sure why it is,but it is.
By the looks of it the KNO3 is the oxidizer, so I would think that the more of it you put in,the faster it would burn
<p>Its definitely possible to supply more oxidizer than there is fuel available. Just like when a campfire burns out because all the fuel (wood) is gone, there is still oxidizer (air) left on our planet after combustion ceases...</p>
<p>Call me ignorant, but is KNO3 poisonous? I don't mean the smoke, but KNO3 itself. I know its used as stump remover, but does it harm humans?</p>
<p>I put it in a metal tube.</p>
I'm just curious,but if you in crease the amount of KNO3,will it burn faster,or will it go ballistic and explode,because that would be bad for me and my rocket
<p>Actually the oxidizer fuel ratio is very precise and adding more oxygen to a reaction will not in any circumstances increase burn rate, really it would just add extra unwanted weight to the projectile.</p><p>-Achmed</p>
<p>Can you tell me what percentage of KNO 3 with air</p>
Me and a friend are doing this for a science fair project, what will happen if we add another flammable acid?
Please tell me if it's safe
<p>@the king of random. Hey I love your work and I'm trying some of your projects. Is it possible for you to do something on homemade fireworks? Where i'm residing fireworks is ridiculously expensive and so i'd really like to build my own.</p>
<p>one thing The King of random I challenge you to make free energy.</p>
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 (&quot;weight&quot; for KNO3/sugar only appeared in the comments, nothing for the rust). <br>
If you read the whole instructable you would see that KNO3, Sugar and &quot;weight&quot; were actually all in the instructable, so I'm confused by your complaint. <br><br>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.
Actually the atomic weight of potassium nitrate Is much light than a sugar compound therefore one part KNO3 is not equal to one part Sugar. This is why we use weight as a unit of measurement when working with chemicals.
<p>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?</p>