# rocket prepellant in the lab

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#### havoc821

##### Well-Known Member
Other day while in Chem II class ( 5 minutes before the bell rang) we had our off topic time and somebody asked if we could make TNT in the lab and of course the answer was no. While on the topic of making stuff in the lab, I asked if we could make AP. She said she wasn't sure about the school regulation. So i thought for a second and tryed to think of a propellant that wasn't regulated and suddenly sugar motors popped into my head after hearing Johnny Paul's and Todd Lumpkins talk about them. So I asked if we could make KNO3 (potassium nitrate) in the lab and she said the we could and she already had those chemicals in the lab. SCORE!!! She (my teacher) is now very interested in making rocket propellant in the lab. We will for sure make the oxidizer (KNO3) but not sure yet if we want to add the fuel because that is when things can get out of hand. She was wanting to put the propellant and make it into an actual motor and fire it in one of my rockets but I told her that we probably shouldn't because that is a whole set of more things to do. It would be pretty hard to make a casing and nozzles considering I don't have or have any plans of buying a lathe. I have been advised from making the complete motor (we were just going to make the propellant and just light a small pile of it in this special thing in the lab that has a protective glass shield, but she is really interested in the complete motor and I was wondering if there were any safe and eay ways to make an actual motor. It would be an endburner (core burning too complicated right now) and probably no bigger than the G size range. Maybe H or I but probably not. Does anybody have advice or anything to offer? I'm not asking for recipies or anything (I can get those on the internet anywhere) just more or less, the motor application part. Thanks!

#### Elapid

##### Well-Known Member
entail the Chem Prof. piling Sodium peroxide mixed with sugar in stoichiometric ratios onto a fireproof surface, then pouring a few mL of regular tap water on the mixture...

the students are surprised that water can START a fire...

the other Professors are irked at the smoke that suddenly inundates the study hall.

#### Ryan S.

##### Well-Known Member
KNO3 sugar DOES NOT have a high enough burn rate (unless some catalyts are used) to be used as an endburner. You really need to make a core burning motor in order for it to work.

end burning motors are tricky, you need lots of insulation

As far as casings go, www.lokiresearch.com

you can get a nice case for 40 bucks

#### havoc821

##### Well-Known Member
does that 29mm case come with closures? Can you buy nozzles from them for that case? Since endburners won't work, how would I make the core of the propellant grain/ I would rather not use a drill bit (turned SLOWLY of course). Is it really coing to be that complicated if she/we choose to do the whole motor route? I mean there is no problem when it comes to the propellant (she's a Chemistry teacher) but I don't have too much knowledge when it comes to the whole motor part. Is this pretty much what I need for the motor:

propellant (DUH)
casing and closures
nozzle
liner
O-rings

It can't be that simple can it? I can order the nozzle, liner, o-rings, and casings from Loki Research and then all I have to do is make the propellant? Is that all? That doesn't seem right. What about AN (ammonium nitrate) is that regulated and does it involve a lot? What catalysts are needed for the KNO3 to work as an end burner? Just curious. Are we getting too ahead of ourselves? I know people are going to say that I'm too young to try this or I don't know what I'm doing but I don't have to worry about the propellant part (teacher will mostly do that and I will help under her supervision of course) but yes, I do need help with the motor part. So before you go shooting down our ideas (I saw what you guys did to Neil when it came to stuff like this and his L3 dreams) could you guys offer some advice? Thanks!

#### Ursa_Major

##### Well-Known Member
I know we shouldn't discuss EX on here, so I won't. But I will point you to a very useful website for information on SU sugar motors: www.jamesyawn.com . The clay you need for the nozzles is Bentonite clay - solidifies under pressure, and you can drill a throat through it.

Just make sure you read, re-read, and read again all the safety stuff first, and make sure your teacher reads the site thoroughly too, so she's familiar with the caveats. Don't skim-read, and if you don't understand, just walk away from the project, don't push it. Pride doesn't burn, but skin does.

Your first 3 considerations should be, in this order, safety, safety and safety.

Remember - if you don't know what you're doing, DFDI*!!

G.

* Don't F*in' Do it, in case you were wondering...

#### Mr.Rocket

##### Member
I would recommend starting out the 5 cent sugar rocket report, just do a search. I started out on these, the ones that work go up several hundred feet and the tools are easy to make.

#### havoc821

##### Well-Known Member
Hey everybody! Thanks for all of the help and advice! I will start with something simple such as a KNO3/sugar motor and progress with different fuels. My teacher has ruled out chlorates because of their unstability, so sorry guys, no AP. We probably won't put this into a rocket for a while, just for safety issues. Since it will be too expensive to order a casing/ nozzle, etc, I will got Homer Hickam style and use some of that electrical tubing pipe (probaly strat with a 38mm motor) and make a nozzle out of a washer welded onto the end. Yes this is crude but I am starting simple. I will experiment with sorbitol and sucrose mixtures as well. This is looking like it will be lots of fun but don't worry we will be very safe. Thanks guys!

#### Mr.Rocket

##### Member
Sorry, but metal cases for amature rocketry is a bad idea, one cato and you may die, rule of thumb....if you can see it, it can kill you. I would recommend you make casings out of kraft paper because the wont cause shrapnel, and nozzles out of clay.

#### Ryan S.

##### Well-Known Member
Originally posted by mr.rocket
Sorry, but metal cases for amature rocketry is a bad idea, one cato and you may die, rule of thumb....if you can see it, it can kill you. I would recommend you make casings out of kraft paper because the wont cause shrapnel, and nozzles out of clay.
that isnt true, when using a fragmenting metal you are right, however, Aluminum (which is what is used) does not fragment and is therefore safe for use. In the RARE event that an aluminum case blows out the side, it peels like a banana, and does not fragment.

#### solrules

##### Well-Known Member
Originally posted by Ryan S.
that isnt true, when using a fragmenting metal you are right, however, Aluminum (which is what is used) does not fragment and is therefore safe for use. In the RARE event that an aluminum case blows out the side, it peels like a banana, and does not fragment.
Plus the fact that many aluminum cases are made to withstand 2000 PSI pressures with a 2x safety factor. Nozzles usually fail before that, making AL based motors very safe.

#### Zippy

##### Well-Known Member
Unless you are willing to use a factory made (or well made by an amatuer craftsman) aluminum case I would also recomend staying away from metal. Remember your teacher is thinking of a safe project that all the class members can participate in too. You can roll many smaller, safer kraft tubes and test burn plenty of them for a low cost. You may understandably want to make the biggest motor you can but a better learning experiance for the other students is to have hands on experiance.
On a side note you are pretty lucky to have a teacher that will do this and a school that actually has some of the stuff needed to start with. In my last science class (many moons ago) we couldn't do any actuall experiments for lack of even the simplist materials. We didn't even have gas for the bunsen burners.

EDIT: Timing is everthing. Ignore my metal comments since they were covered by others before I could post.

#### jyawn

##### Member
I just happened upon this fine forum and lo and behold... my name and not in vain!

Nice to see that someone actually reads my pages, especially the safety part!

Experimental motors can be made safely, but it takes a bit of knowledge, maturity, and restraint to keep from getting burned. Seems like "havoc" and his teacher might qualify.

I understand that this forum is not about experimental rocketry, so instead of muddying the waters here, I suggest contacting me directly, and getting that chem instructor to do so too.

Experimental rocketry is not about being cheap. Purchasing certified motors is cheaper. Experimental is about learning.

This might be a fine opportunity for you to teach the teacher. Seems like you might have more knowledge and maturity regarding this endeavor. If she has never built and/or flown a model rocket, you might want to encourage her to attend a launch, build a kit, and learn the ropes.

Once the airframe, recovery, launch systems, launch site, and attitude toward safety are worked out and proven functional, then might be a good time for her to take on motor construction.

So please feel free to contact me directly, and to forward my name and e-mail to your instructor!

Sincerely,
Jimmy Yawn
[email protected]
www.jamesyawn.com

#### DynaSoar

##### Well-Known Member
Originally posted by Ryan S.
that isnt true, when using a fragmenting metal you are right, however, Aluminum (which is what is used) does not fragment and is therefore safe for use. In the RARE event that an aluminum case blows out the side, it peels like a banana, and does not fragment.
I will not describe the processs and events whereby I disproved the assertion that aluminum will not fragment. It is precisely the sort of thing that BATF would enjoy hearing because it would prove their point regarding "other" uses of propellant. It was 35 years ago.

Regardless, a metal motor and nozzle at high speed is dangerous. It is also likely to be so far outside the allowable activities for the school's liability coverage that attempting to do it there will result in not being allowed to return, at the minimum.

There are safer, easier alternatives. These should be explored and learned from thoroughly before attempting to move on to metal. Dollars to donuts, if you asked Homer Hickam if he'd have used safer alternatives had they been available, he'd say yes.

#### MarkABrown

##### Well-Known Member
Originally posted by havoc821
I will start with something simple such as a KNO3/sugar motor and progress with different fuels. My teacher has ruled out chlorates because of their unstability, so sorry guys, no AP.
Chlorates and Perchlorates are two totally different things. Perchlorates don't have nearly the stability issues as a chlorate does.
Originally posted by havoc821
Since it will be too expensive to order a casing/ nozzle, etc, I will got Homer Hickam style and use some of that electrical tubing pipe (probaly strat with a 38mm motor) and make a nozzle out of a washer welded onto the end. Yes this is crude but I am starting simple.
Electrical tubing is not aluminum, to the best of my knowledge, and welding a washer for a nozzle is just asking for trouble. There is a reason that experimentalists today use the materials they do. They've proven more reliable and safe than the things Homer Hickam used in the 50's. Please reconsider trying to start EX "on the cheap" and be safe.

#### powderburner

##### Well-Known Member
Originally posted by solrules
Plus the fact that many aluminum cases are made to withstand 2000 PSI pressures with a 2x safety factor.
Even if the tubing IS aluminum (and I have to agree with Mark Brown---the only conduit material I have ever seen is steel), and even if it IS rated at 2000 psi, that does not make it safe for a rocket motor casing.

Conduit is used at room temperature. For whatever reason it might be pressure-rated, it would be at (or near) room temperature.

Metals get soft quickly when heated and their structural properties ('allowables,' in engineer-speak) go away in a hurry. Aluminum will not only weaken, but will MELT at the temperatures reached in the combustion chamber. Do not attempt metal motor casings, especially if this is one of your first steps into EX-type rocketry.

There is a reason that paper casings are used for millions of small motors. You really need to pay attention to those lessons.

Sorry if this sounds like a lecture (I guess it is one, anyway) but metal casings really are a very very bad idea.