Rocket fuel - Archive file

[zaibatsu]

extreme
Frequent Poster
Posts: 102
From:
Registered: SEP 2000
posted January 19, 2001 12:30 PM
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I got a recipe for rocket fuel from the "THE INCREDIBLE FIVE CENT SUGAR ROCKET REPORT"

SALTPETER...........................63%
SUGAR...............................27%
SULFUR..............................10%

It says that i have to melt the ingredients together, a simple question, why?
Anyone have any nice tips for rocketbuilding / fuel?

Agent Blak
Frequent Poster
Posts: 765
From: Sk. Canada
Registered: SEP 2000
posted January 19, 2001 02:01 PM
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I thought that you could just pack the fuel in there tightly(16oz. Rubber Mallet and rocket tools); this is the way I make my KNO3/Sucrose. They preform Fine and it is safer due to the fact you don't heat it up.

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A wise man once said:
"... As He Waits For The Time When The Last Become First And,
The First Shall Become last"
--RATM

Agent Blak-------OUT!!

Anthony
Moderator
Posts: 2304
From: England
Registered: SEP 2000
posted January 19, 2001 04:31 PM
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Melting the mixture increase in intimacy of the mix, thus raising the burn rate.

extreme
Frequent Poster
Posts: 102
From:
Registered: SEP 2000
posted January 19, 2001 05:02 PM
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I havent got any of minerockets to work yet, do you pack the propellant well?
And what casing do you use?

vehemt
Frequent Poster
Posts: 580
From: Canada
Registered: SEP 2000
posted January 19, 2001 05:15 PM
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You ingredients need to be a fine dust to work. Melting is only required for larger rocket motors. Anything smalled than 3/4" ID would be too much trouble to melt and cast. These rockets typically need a core to work.

Agent Blak
Frequent Poster
Posts: 765
From: Sk. Canada
Registered: SEP 2000
posted January 19, 2001 06:42 PM
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The tools I built(Thanks to the schools machine shop) were for 1/2" CPVC Rockets.
VeHeMT is who I go the plans(Dimentions, I used BrasS and Steel) from. I milled my rocket Fuel in a "Coffee Grinder." I use a Body filler["Bondo"(See the end plugs post in the LE section)]. I prime the core with Pyredexstuck my visco in there and sealed i with NC Laquer(Ping Pong).

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A wise man once said:
"... As He Waits For The Time When The Last Become First And,
The First Shall Become last"
--RATM

Agent Blak-------OUT!!

ALENGOSVIG1
Moderator
Posts: 766
From: Vancouver, Canada
Registered: NOV 2000
posted January 20, 2001 12:25 AM
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for info about rockets, goto my rockets section in my site : <a href="http://surf.to/alexplo" target="_blank">http://surf.to/alexplo</a> or 24.115.54.237 which isnt always runnig due to sonstant changes

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Explosives Archive

[This message has been edited by ALENGOSVIG1 (edited January 20, 2001).]

firebreether
Frequent Poster
Posts: 108
From:
Registered: NOV 2000
posted January 26, 2001 12:07 PM
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I have been looking into using Ammonium Nitrate as a rocket fuel. It would burn slower than a Potassuim Nitrate fuel but produce a higher total impulse and specific impulse. Probably burn hotter too. THe reason I think it has a higher impulse is because it produces more volume of gas and a lower molecular weight. I will make an engine within a few weeks hopefully and I will try launching a rocket with it after that.

firebreether
Frequent Poster
Posts: 108
From:
Registered: NOV 2000
posted January 26, 2001 12:12 PM
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I meant AN as the oxidizer (duh) and the fuel would be either AN/Mg/R45 check out <a href="http://members.aol.com/SspacePyro/" target="_blank">http://members.aol.com/SspacePyro/</a> or I will use a simple sugar. Maybe in the sugar I will add some Al powder for an extra kick, however I need to find a good way to make super fine Al powder as I don't want to buy any because it would cost too much on my already tight budget.

Mr Cool
Frequent Poster
Posts: 991
From: None of your bloody business!
Registered: DEC 2000
posted January 27, 2001 09:24 AM
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When making my KNO3/sorbitol rockets, I melt the ingredients together at 130 *C, and they work great. Packing the powders together with a mallet and wooden dowel in the rocket motor isn't quite as good, but it does work.

Brainmonkey
A new voice
Posts: 37
From: Derry, N. Ireland
Registered: JAN 2001
posted January 27, 2001 06:20 PM
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how about using ammonium perchlorate/aluminium mix, thats what they use in the SRBs in teh space shuttle, if they can lift that they can lift anyhting, they would need to nbe cast tho, as it is amde as a kind of slurry

SafetyLast
Frequent Poster
Posts: 232
From: the cretaceous period
Registered: OCT 2000
posted January 27, 2001 07:27 PM
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Actually I think they use Ammonium Nitrate w/ Magnesium powder and HTPB binder. <a href="http://www.pyrotek.org/High_016.html" target="_blank">http://www.pyrotek.org/High_016.html</a>
a lot better (safer) than a cast flash powder

firebreether
Frequent Poster
Posts: 108
From:
Registered: NOV 2000
posted January 28, 2001 01:55 PM
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No, Shuttle uses Ammonium Perchlorate and Al powder with a few agents that slow the burn rate waaaay down and make a hard cast grain. The Ammonium Nitrate, Mg or Al, hardeners I think is a good fuel too since AN is easier to get and it has still a high impulse.

Brainmonkey
A new voice
Posts: 37
From: Derry, N. Ireland
Registered: JAN 2001
posted January 30, 2001 06:16 PM
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any ideas on what they put in the mix to slow it down, cos i reckon one of those would be fairly impressive to shoot at someones house/car/helicopter/armored tank

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ours is not to question why.. ours is but to do and die...
yeah right so whose gonna try and tell me what to do?

[Rat Bastard]

Speaking of the "The Incredible Five Cent Sugar Rocket" here is a nice article by Zero The Inestimable:
http://krimzonpyro.com/zero/Articles/Sugar_Rockets.html

A very good read, and has worked for me.

[arm]

Hi,

Ive tried the 75/25 KNO3/Sucrose mixture and have always found it to be over-oxidised (white perls on burning). 65/35 KNO3/Sucrose gives the best results for me. Zero also suggests the addition of iron oxide, how much of an improvement does this give? It should be noted that standard rust isnt just Fe2O3 (red iron oxide), but a mixture of various oxides and hydroxides.

Also, in the "Increadible 5 cent Sugar Rocket" what purpose does the sulfur serve? To lower the ignition temperature? Ive always found the above mix very easy to ignite.

the arm.

[Guerilla]

The point is the Five Cent Sugar Rocket formula is bunk. The regular old 6 to 4 potassium nitrate and sugar mixture (also often quoted as a smokebomb mixture, a task for which it actually works) burns far too slowly and with too much byproduct to function as rocket fuel. Adding the sulfur to the mixture, as the Sugar Rocket plan suggests, only makes matters worse.

I don't get that.. from my experience 75/25 must be caramelised to get it perform even nearly as good as porous KNO3/S/Sugar/(catalyst). At least I can't see why adding sulfur would anyhow make it worse?

About that iron oxide, it really doesnt matter all that much, every iron oxide will do, Fe2O3 and Fe2O4 are the bests though.. You could look it at the hardware stores, it could be sold as a paint pigment. An illustrating burn rate test (http://www.jamesyawn.com/fe2o3/index.html) of KNO3/Sugar/Fe2O3 (the samples arent lit at the same time, doh!).

[xyz]

The reason that sulfur supposedly makes things worse is because it uses up lots of oxygen when the mixture already only just has enough.

In my opinion, 65/35 KNO3 and Icing Sugar is the best sugar rocket fuel, I hope to try catalyzing this fuel with Fe2O3 soon.

[kingspaz]

various metal oxides can be had from pottery supply shops. the oxides are quite pure (greater than 95%) and also quite cheap :)

also barium carbonate can often be purchased which could be useful for synthesis of barium nitrate. barium carbonate has a high decomposition temperature but with enough heat it should decompose to barium oxide which could then be reacted with ammonium nitrate to make the barium nitrate and ammonia.

i got bit off topic there...

[Guerilla]

Actually the decompositing isn't necessary. If you add BaCO3 to a boiling (or >60C IIRC) AN solution it will dissolve forming barium nitrate and ammonium carbonate which decomposes to carbon dioxide, water and ammonia. Boiling is continued until ammonia doesent smell anymore. Just boil the water down and you'll have pure barium nitrate crystals.

2 NH4NO3 + BaCO3 => Ba(NO3)2 + CO2 + 2 NH3 + H2O

However, the carbonate I got from a ceramics supply store was probably contamined with BaSO4 which have to be filtered away before the final crystallisation.

[kingspaz]

i was going to suggest that but when attempting this using calcium carbonate i found the reaction to be incredibly slow. using an oxide improves reaction time considerably.

[Arthis]

Some friends of mine have recently been amazed in making small rockets. They use NaClO3 + sugar composition, (they decided not to use gas anymore) and they had a security starter with monostable switch (those that come back to the off position if you stop pressing them). But later they had to make another one and only had bistable position switchers. No matter they used one.

Then, they made a small rocket and fired it in their garden ( !!! ) and the rocket went in the neighbour's garden, his small daughter was effraid, ran into the house crying... My friends, ran back to their house, they feared problems and bad consequences. A bit later they made another rocket in a PVC tube, and when connecting it, it fires .!..!
They had forgotten to put the switch off. And, one proble never comes alone - as well described by the law of murphy -, and this time the rocket wasn't well made and it exploded instead of flying.

Consequences:
- hehe their first accident, maybe not the last...
- always take a maximum of precautions
- be careful with ignition systems
- sugar + XX compositions may be more unstable than one thinks
- one of the two guys had an eardrum broken.

[arm]

Hi all,

Yeah, you have to go a little OTT with safety, there are enough stories of people loosing body parts in the papers. In a another thread i was talking about a little incident i had with fulminating powder. The one piece of safety equiptment i had forgotten was ear protection and guess what, there was an explosion and i lost my hearing for a day.

If youre gonna be firing rockets/testing motors its best to do it outside in a remote location where theres no possibility of property/people damage.

I must say though i havent had any bad experiences with sugar/KNO3 mixes. They are resilient to overheating and have never auto-ignited on me because of that. Explosion of motors is usually due to things such as insuffient compression and air pockets in the propellant or propelland/wall interface.

I know whats its like though, you have a few failiars with experiments and then get a little impatient and lax on safety.

arm

[arm]

Hi,

About the Fe2O3 from wire wool that zero suggests...I have found that it takes a lot longer than zero states to fully oxidise the steel. Several days infact.

Just in case i washed the wool in white spirit and then detergent to get rid of any protective oil coating. Plus, the wool used was of a very fine grade. After the required 1 hour in the vinegar and half and hour in the air, the wire still had a great deal of strength (i would have expected it to snap easily).

Has anyone else experienced this problem or am i missing something bigtime??

[Rat Bastard]

It could be that you are using a thinker brand of steel wool. My hardware store sells it in Coarse, medium, fine and superfine.

Ive tried the 75/25 KNO3/Sucrose mixture and have always found it to be over-oxidised (white perls on burning).

Strange.... mine does not leave many pearls behind. I noticed that 6/4 leaves a lot of black crap behind and burns slower. I allways melt my fuel, I have never had an inccedent with it overheating and burning.

[xyz]

Are you using pure KNO3 Rat Bastard? I always find that 75/25 KNO3 and Sugar leaves white KNO3 beads as well.
What type of sugar did you use? Some Icing sugars have starches and other stuff in them as well and this could affect how much oxygen they use.

[Guerilla]

As a candy mix, the 75/25 ratio burns faster and doesnt caramelize as easily as 6/4. Maybe Rat Bastard has meant all the time only molten mixes..

In a powder form, 6/4 sure is a lot better and leaves almost no slack if properly mixed and finely grinded. If sulfur is used, it's added so that it replaces a part of sugar otherwise you're overfueling the mix.

[xyz]

I normally use a 65/35 mix of KNO3 and Sugar and I find that this is a very good fuel in both powder and candy forms. It leaves almost no trace of anything in candy form and it only leaves a small amount of black stuff in powder form.

[arm]

Hi lads

Yep 63/35 for me too if its sucrose/KNO3 (other sugars and oxidisers need a different ratio, naturally). I did a little experiment recently. I made up a batch of melted 63/35 KNO3/sucrose then after it had cooled rock solid (i layed it out real thin for this) i crushed and powdered it. Naturally i then tested it......Whooosh.....went up in one go leaving virtually nothing at all behind. The fastest/cleanest ive seen the stuff burn yet - might actually be good enough for lift charges/breaks.

Also, got fed of waiting for my wire wool to rust and bunged it in the oven. This actually seemed to finish the oxidation process off - the resulting iron pretty much crumbled away. Although, annoyingly there were still a few bits of wire left. Ive just been desperate to try this stuff to see what an improvement it makes.

[DaveTheShit]

Just in case any of you haven't seen this site :JamesYawn.com (http://www.jamesyawn.com) . It's a good site, and somewhere in there is a video of Fe2O3 catalysed rocket propellant burning next to normal candy propellant. He also uses a cool technique of recrystalising the KNO3 and sugar together that seems like it would result in good propellant because of the KNO3 and sugar being so close together. It's worth your time to check it out.

[xyz]

arm, You could use a magnet to remove any un-oxidised iron.

[arm]

Cheers xyz,

Will give it a go......when i get my hands on a fat ass magnet.

[Arkangel]

David, went to that link, and it's a noce site. Just thought it was worth posting a link to the guy's safety (http://www.jamesyawn.com/rcandy/safety.htm) page, as it's clear and easily digested. Might be worth posting somewhere else as a seperate thread - if anyone wants to.

[Mr Cool]

Arm, just make sure that you wrap your magnet in cling film first. There is nothing more annoying than a magnet covered in iron filings, I repeat, NOTHING.

I've just started browsing that site, it does look good!

[arm]

Oh yeah, i remember all the science experiments when at primary school where you pick up the iron filings with a magnet or make lots of pretty shapes on paper. It was a real bastard trying to get em back off again.

[Arthis]

stupid teacher ! :)

normally you put the iron on the paper and the magnet under that paper...

[arm]

You know what its like when your a kid, everything seems like a good idea:

"Ohh, i wonder what happens if i drop the magnet into this big bucket of filings".

-A pretty good bollocking from the teacher thats what.

[arm]

I've been searching for an alternative to the slighty dodgy melting of nitrate/sugar together and i think ive found a pretty good one. Note that i add my nozzles afterwords using plaster.

It involves the use of nitrocellulose to bind the composition.

First as usual you mix your fuel and oxidizer. I used a 65/35 ratio of KNO3/sucrose. Both ingreadients were milled to a flour consistency (the powders should not feel gritty and should readily float on air). For low sensitivity/power mixes i use the ball mill to mix - tilted up with the lid left open to avoid possible explosions. The comp was mixed for 20-30mins.

The next step was to add the nitrocellulose. Ping pong NC is all that is needed here - it must be mixed with acetone to form a fairly thick lacquer. Probably around as thick as thin honey. Enough of this should be added to make the mix into a thick by plyable dough. I think around 15ml per 28g comp.

The comp must then be rammed into the motor body. The pressure is nowhere near that of normal ramming and can just be hand rammed with the former for the tube. Note that you dont have to use rocket tools here - the core can be (carefully) added afterwards.

Now using a pointed metal tool (other tools would stick) make a core in the propellant. A twisting action ensures that the propellant doesnt stick.

Now the drying. This stuff takes bloody ages to dry. I'd give a 3/4" rocket a week to dry. The drying location should be dry and warm.

Now the performance. To me it actually appears to burn faster that normal KNO3/sucrose with a cleaner exaust. I havent had an explosion (yet) and i would imagine that the NC lacquer would waterproof the comp fairly well.

[Guerilla]

Sounds like a practical way to make solid grains without much of pressing or ramming. however the idea of the candy fuel is to get the propellant into a dense and an intimately mixed form by melting, which considerably increases the burn rate compared to a porous fuel. the increased sensitivity to friction (unless the cores are drilled when the comp is still damp) and the long drying times are drawbacks too, like you stated.

[Microtek]

Also note the problem of voids left behind when drying acetone/NC mixes in thick layers; I'm pretty sure that you will find lots of voids if you cut the grain open. It may not be a big problem with candy propellants as they are so relatively benign, but try it with a whistle mix and it will explode every time.
Now that we are on the subject of NC-bound compounds and voids, I have designed a method to work around those drawbacks. It also requires less acetone ( and possibly less nitration acids ):

Powdered Nitrocellulose.

The idea is to produce a finely powdered high density nitrocellulose for use in compositions.
This is accomplished by powdering the cellulose before nitration in one of two ways presented below:

1)
- Add a few cotton papertowels and some water to a blender and blend for 5-10 minutes.
- Filter off the paper mass and add it to a warm dilute soln of NaOCl.
- Allow it to sit for an hour or so at 50-60 C, then filter and wash the fibers ( which should be relatively short ).
*- Drive off most of the water, and when a dough-like consistency is reached, granulate the paper by kneading it between your fingers. The granules must be as small as you can make them.
- Bake the granules in the oven until they are completely dry. They will shrink and become hard enough to grind in a mortar or ball mill into a very fine powder.
- Nitrate the powder in the usual way.

2)
- Aquire a piece of hardwood and grind it down into fine sawdust ( the finer the better ).
- Digest the sawdust in a soln of NaOH for an hour at 50-60 C. This dissolves most of the lignin between the cellulose fibers in the wood. It will still be yellow or orange.
- Decant the liquid and transfer the powder into a dilute soln of NaOCl and digest at 50-60 C for an hour. This oxidizes remaining lignin and other impurities and bleaches the mass. It will be white when done.
- Proceed as in the first method from *

The product of the nitration is completely dissolved by acetone but does not burn quite as cleanly as ordinary NC. However, it has one great advantage over the fluffy usual NC in that if an NC-bound composite ( whether HE or propellant ) is desired, then the powdered NC can be mixed with the other solids obtaining a homogenous powder. Then the plasticizer can be added ( with minute amounts of solvent if desired ) and the composite can be kneaded and pressed into the desired shape. If NG is used as plasticizer and no solvent is used, the mass will remain workable until the composite is cured ( colloidonized ) by heating to 40-50 C for an hour or so.

[Arthis]

Today I was trying to make some fireworks: you take some paper to make the tube, closed at the top with paper too, hold with scotch (scotchtape you fat stupid boy ! scotch (the drink this time) is for this evening ;)). This is filled with KNO3/sugar propellant.

There comes the problem: there was not propulsion enough to make it "fly". The tube was sealed at the top only. Size: 10 cm, with 8 mm diameter. I know my propellant was not really well dosed, still I guess it should have been propulsed. Where's the trick ? What did I forget ?

Yes I'm kinda stupid sometimes, I'd like to make a few for saturday evening, for a party on the beach... I only try now to make some, but as I don't work today neither tomorrow it gives me a little time for pyrotechny. :)

[Guerilla]

If you weren't a member with that much of posts, you sure would get flamed by some people..but that's not my business.. if you want your rocket to fly you will use a nozzle and an endplug, preferably also melt the fuel and drill a core.

[arm]

Oh man, arthis

You should be voted "The man most likely to blow himself straight to hell". Only Joking. Yeah you need to either, very fucking carefully melt the Sugar/KNO3 together or ram/press the powdered propellant into the tube.

If your gonna melt, for gods sake use an oil double boiler or a thermostatically controlled hotplate. No naked flames otherwise your last words could be "Oh fuck i'm on fire".

You can use clay for an end plug but i find certain plaster's work well too.


As you know theres loads of info here on how to do it.

[Arthis]

Yes I know it's a pretty dumb question, I'm really sorry, (and that's why I wouldn't have started a topic...), but I haven't been really aware in pyrotechnics, and I was just wondering whether my problem was due to the propellant or not. It seems that both shaping and propellant are involved in that failure. Thanks anyway, this was my dumb question of the year, gonna be wiser now ;)

[Anthony]

You can melt KNO3/sugar relatively safely. I haven't done it for a while but when I did, I used a gas camping stove and an old saucepan.

Obviously do it outside! Don't pile too much in the pan, a lesser depth of mix is easier to stir and keep and eye on what the stuff at the bottom is doing. Also *always* keep it moving, otherwise the stuff at the bottom will decompose and ignite before the stuff at the top has even begun melting.

Don't put your face or any body part over the pan, work at arms length. Don't sit down, stand or squat if working on the ground. This lets you move back very quickly if something goes wrong.

Generally, it's best to assume that it *will* ignite at some point and make sure you're prepared to deal with it.

There's no explosion risk and the flame will go pretty much straight up, so you're pretty safe as long as you're not over the pan :)

[iron raven]

hello,
i use 1 part sugar to one part KNO3(volume) 0.25 iron oxide a catlausit. i know they say that this wrong to do it in volume but this is how i did it when i didn't have a scale. i got the iron oxide from my dads old tralier. It works like a charme. this mix seems to live very little or no visble slag.
master of the atom
iron raven