120 lbs thrust rocket engine went 3.5 miles

Moderator: Mike Everman

Post Reply
Rocket Man
Posts: 144
Joined: Sat Sep 26, 2009 9:59 pm
Antipspambot question: 125

120 lbs thrust rocket engine went 3.5 miles

Post by Rocket Man » Sat Sep 17, 2011 12:49 am

This is the first time I have seen this part of the forum. I wrote a book on solid fuel rockets and I use to sell a lot of them 25 years ago in the classified section of Poplar Science that was back in the days when people bought magazines and there was no internet. I have not been able to sell many of these on ebay. I have seveal proven designs the smallest engine is 35 lb thrust and the larges is 120 lb thrust. Propellant is Potassium Nitrate, Sulfur, Charcoal and Linseed oil. Solid fuel rocket engines are basically a controlled explosion. 27 years ago I use to build lots of them they were 99.9% safe that .1% is the one that will blow off both your arm or kill you so I never trusted them 100%. Fire them all off from a safe distance. My 120 lb thrust engine would go 3.5 miles I use to load them with 5 lbs of explosives I could hear them when they hit the ground. The 35 lb thrust engine goes 1/4 mile in about 4 seconds.

I don't know why people try to get potassium nitrate from stump burner or urine in wood ash when you can buy it is 50 lb bags from any industrical chemical supply company. It use to sell for 25 cents per lb 20 years ago its probably $1.00 per lbs now. Sulfur comes in 30 lb bags and charcoal comes in 30 lb bags too both are very cheap about $20 per bag. You can buy linseed oil at any hardware store or paint store by the quart. Most garden suppy stores and farm supply stores have sulfur in 3 lb bags for $20.

You need to make your rocket nozzles out of fire clay.

Rocket engines need to be cardboard tubes just in case they explode you don't have flying metal or plastic pieces that will kill you.

Jutte
Posts: 332
Joined: Wed Aug 22, 2007 11:01 am
Antipspambot question: 0
Location: NZ

Re: 120 lbs thrust rocket engine went 3.5 miles

Post by Jutte » Wed Sep 21, 2011 7:00 am

Hey Rocket Man - 20-25ish odd years ago was a more 'innocent' time.

Mark
Posts: 10931
Joined: Sat Oct 11, 2003 10:14 pm

Re: 120 lbs thrust rocket engine went 3.5 miles

Post by Mark » Wed Sep 28, 2011 3:47 am

When I was about 11 or 12 I bought 3 fifty pound bags of KNO3 for a grand total of $9.00. My oldest brother bought me a blower that I used to grind the prills. I put a funnel in the intake and a double pillowcase on the out side. If you ran the prills through twice is was like dust. The blower had many blades just like a jet engine and in fact it sounded sort of like one when it spooled up. If you lifted it and tried to turn it, you could feel the force like a gyroscope.
I made a lot of little rockets and one time I lit an entire large coffee can of KNO3 and sugar. I thought the police would come the cloud went so high up in the sky, it was kind of spectacular. I got my gunpowder to burn pretty fast too, in a quick poof.
Back then, you could buy 75% calcium hypochlorite pool chlorine and it would spontaneously ignite with sulfur after a bit or if you put a drop of water on it, it would start quickly. Or you could try various oils or other odd things like Cox glow fuel. The off-white granules would then turn a bright orange and then burst into flames, calcium making a pretty red color. And about 10 years ago or so I bought a 50 pound bag of NH4NO3 for 6 dollars about a mile from my house at a garden store. WIth that you could mix it with pool chlorine and it would crackle and pop fiercely creating rapid fire firecracker type sounds and looking something like popcorn gone crazy as particles fly about ejecting off the pile; sometimes I would put it in a can instead of on the ground. It made a fair amount of smoke you probably wouldn't want to breathe. If it didn't start on it's own after a minute you could wet it to get it started. With powdered zinc, ammonium nitrate will also catch fire. I remember the prettiest color smoke I made using these two ingredients and iodine crystals. Iodine smoke is very vivid and with the NH4NO3 it really adds to the effect. Imagine a billowing smoke that is intensely blue transitioning to some kind of indigo violet as it cools, the smoke looks soft almost, it's hard to describe.
But then I guess I grew out of that phase, playing with sodium and such. Once you do all the neat experiements you can find, it's kind of no fun to keep repeating the old ones. And today it seems things are getting more and more controlled. Iodine and ammonium hydroxide make a classic super sensitive explosive a fly can set off, yet both these chemicals raise eyebrows these days, maybe get your name on a government list. Oh!
Presentation is Everything

Rocket Man
Posts: 144
Joined: Sat Sep 26, 2009 9:59 pm
Antipspambot question: 125

Re: 120 lbs thrust rocket engine went 3.5 miles

Post by Rocket Man » Wed Oct 05, 2011 1:01 am

I use to buy Potassium Nitrate, sulfur and charcoal at industral chemical supply. There are industrial chemical supply companies all over the USA they are use to selling to factories and other industrial companies not people like me and you. So you walk in and say, I want to buy 75 lbs of Potassium Nitrate, 10 lbs of sulfur, 15 lbs of charcoal its no problem at all and it is cheap. Potassium Nitrate comes in 50 lbs bags and 600 lb barrels. Sulfur comes in 40 lb bags and charcoal comes an a GIANT 25 lb bag. Powered charcoal is light wt and styrofoam so a 25 lb bag is very large. I use to mix it in a old cement mixer with several iron or lead balls rolling around inside for 3 days. 75 lbs of Potassium Nitrate and about 5 gallons of warm water to dissolve it. Add 15 lbs of charcoal and let it run for 24 hours then add 10 lbs of sulfur and let it run 2 more days. Dump it on a large sheet of plastic and spread it out 1/4" think until it dries about 4 days in hot summer weather. Then add 2% linseed oil put it all back in the mixer for several hours. Now it is ready to make rocket engines. Compact it hard as stone in the engine body the linseed oil dries and acts like the binder. Pull the core pin out of the center of the engine and its ready to shoot.

Interesting thing about Potassium Nitrate if you mix it 50/50 with Ammonium Nitrate plus charcoal and sulfur like above you get an unstable chemical. In warm weather it will self ignite in about 1 to 3 months. So you don't keep this in your house, your garage or your car it will burn the place down. If you mix this stuff up in the winter when it is cold it is pretty safe until warm weather but you need to keep it cold to keep it from self igniting in about 1 to 3 months. Best thing is not mix this at all you spill a few drops on the floor and you have a fire in a few months.

There are some chemicals you just don't mix together. Most people have experemented with Nitrogen Triode or how ever it is spelled I forgot. Mix Iodine with laundry ammonia stir for 20 minutes at 70 degrees then pour it through a coffee filter you have a tiny amount of red/brown mub looking high explosive that is dangerious as hell when it is dry. You touch it with a feather it will explode and blow your face off. Ammonium Nitrate and Beach is another one not to mix the gas it produces is a very high explosive and self detonates above 95 deg F or when it comes in contact with sunlight. Magnesium is extremely dangerious under certain conditions. Potassium Chlorate mixed with any combustable material is extremely friction sensitive and can get you killed. Potassium permagnate and glycerine will ignite and burn like thermite same thing for potassium permangate and table sugar if it gets wet. These are things you need to know for safety reasons. Don't mess with this if you value your life. Young kids like to mix things together to see what happens, lets mix this, lets mix that, next thing you know someone gets killed. If you don't know for sure what it does don't do it!!!!!

Jutte
Posts: 332
Joined: Wed Aug 22, 2007 11:01 am
Antipspambot question: 0
Location: NZ

Re: 120 lbs thrust rocket engine went 3.5 miles

Post by Jutte » Sat Oct 08, 2011 10:05 pm

Nitrogen triiodide = big time senstitive - impressed the heck out of my chemistry teacher
Potassium permagnate and glycerine = 'Purple Sludge'

Some of the names from my long ago youth... :D
One of my fellow experimenters now is a Ph.D Chemistry University whizz -
which goes to show that some youthful hobbies do actually lead to useful careers !

Rocket Man
Posts: 144
Joined: Sat Sep 26, 2009 9:59 pm
Antipspambot question: 125

Re: 120 lbs thrust rocket engine went 3.5 miles

Post by Rocket Man » Wed Dec 17, 2014 10:31 pm

Another thing that is extremely unstable is Ammonium Nitrate mixed with laundry bleach. This forms an explosive gas that is unstable at or above 95 degrees F, unstable in direct sun light too. In the summer after the sun goes down and the temperature drops put the gas in balloons. This is a funny prank to play on friends. Tie the balloons up in a tree at your friends house next day when it gets hot outside BOOM. You can drive your friend nuts. He runs outside to look and no one is there. This stuff must have a high detonation rate close to 8000 ft sec because the Boom from a balloon sounds like a tiny piece of C4. I never could get it to go off in direct sun light but it sure the heck is sensitive to temperature change from 94 degrees to 95 degrees BOOM. I am not sure you can detonate this stuff with a flame I never tried it. We filled up 100 empty 1 gallon milk jugs 4th of July put them all in the back yard lined up real nice in a perfect square shape. Next day about 12 noon WOW what an unreal explosion it shook the house like an earth quake. People came out of the house in all directions for 5 city blocks looking to see what that was. There is no smoke and no flash. The back yard liked like it snowed the yard was white with 1,000. tiny pieces of shredded milk jugs. LOL. Don't play with this stuff it is too dangerous.

I don't understand why people make sugar explosives it so worthless compared to much better stuff.

Yes Potassium permagnate is interesting stuff too. Potassium permagnate and glycerine ignites above 70 degrees. Potassium permagnate and sugar ignites if it get wet above 70 degrees. Potassium permagnate and hydrogen peroxide makes some extremely powerful rockets. The German WWII ME262 was powered by Potassium Permagnate dissolved in water and alcohol + 85% hydrogen peroxide. You get a controlled continuous explosion inside the rocket engine.

tufty
Posts: 887
Joined: Wed Dec 24, 2003 12:12 pm
Antipspambot question: 0
Location: France
Contact:

Re: 120 lbs thrust rocket engine went 3.5 miles

Post by tufty » Fri Dec 19, 2014 12:09 pm

Rocket Man wrote:Yes Potassium permagnate is interesting stuff too. Potassium permagnate and glycerine ignites above 70 degrees. Potassium permagnate and sugar ignites if it get wet above 70 degrees. Potassium permagnate and hydrogen peroxide makes some extremely powerful rockets. The German WWII ME262 was powered by Potassium Permagnate dissolved in water and alcohol + 85% hydrogen peroxide. You get a controlled continuous explosion inside the rocket engine.
Not the ME 262. That was driven by a pair of Junkers Jumo turbojets. You're thinking of the ME 163 , although that used Hydrazine / Methanol "C-Stoff" fuel with Hydrogen Peroxide "T-Stoff" catalyst on the "production" models. I'm not aware of any rocket engines using Potassium Permanganate ("Z-Stoff" was, I think, Calcium Permanganate, Sodium Permanganate, and water). Z-stoff was used as a catalyst in the early "cold" engine on the ME163 prototypes, which Lippisch considered too dangerous to use.

Yes, I worry about this sort of thing too much.

Post Reply