Instructables

Turn Empty Water Bottles Into Alcohol Fueled Rockets

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video Turn Empty Water Bottles Into Alcohol Fueled Rockets
Not long ago I was challenged to create a project using a water bottle that could be displayed in a one minute long video. While I missed the one minute mark, I think I still managed to make a pretty entertaining device.

The rocket and launcher featured in the above video function off of a very simple concept of igniting a flammable vapor using a replacement barbecue igniter to propel the bottle through the air. The parts for this project should cost no more than $15, with the igniter taking up the majority of that price tag at about $10. The bottles can be reused many times until the heat from repeated shots eventually warps the plastic.

Be sure to check out my other Instructables, and take a moment to subscribe to my YouTube channel: http://www.youtube.com/user/Nighthawkinlight

Thanks for reading!
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I made it! I was put off by the expense of replacement bbq ignitions and so I ended up trying it using a standard bbq lighter (you know, the long handled butane lighters). I was quite pleased with the overall usability and the built in trigger mechanism. We get fabulous launches with 99% rubbing alcohol.

I'd recommend against anything like acetone or gasoline, contact with either has been show to be carcinogenic. They're also a bit more dangerous as their burn rate can be explosive.

Perhaps aerosolized cigarette lighter fluid would work. (Like they use in Zippos). It can cause skin irritation, but has no warnings on the package about carcinogens... I've also seen hairspray or even aerosol sanitizer (high proof alcohol) used in potato gun / launchers. Could be fun to experiment with.
Naptha - The lighter fluid you're mentioning - Is the most volatile part of the liquid petroleum distillate.

All of the other fluids you mentioned are carcinogens as well.
Naptha has a lower flash point, and is as you mentioned a carcinogen as well. So don't let it on your skin, avoid any contact. It's nowhere near as explosive as gasoline, in my experience. It has a slower burn rate and isn't as dangerous as gasoline.
Dillon123 2 months ago

I made it and singed the hair on my arm!

5VOLTSGC2 months ago

I made one this weekend. It was really easy to make. I reused one water bottle so many times that it finally ruptured. So wear your safety glasses when using this rocket launcher!

rjkorn3 months ago

I gotta make one this weekend. I even got a can of hair spray at the dollar store. you know the kind where the flammable warning is the biggest thing on the label......

Like the idea of a 2 liter bottle as a blast sheild

love it

richsmo3 months ago

One tip i have instead of using duct tape, use a candle or lighter to heat up the pipe and push it together to create a bulge in the PVC. That will create a seal pretty easy as well. I have used that method before to make a bottle rocket launcher for one of my classroom activities and it worked pretty well.

Pas1934 months ago

I have tried the expirement, but instead of the igniter, i chose the lighter, and it doesn't work quite well.i fired at he cover place and the only thing happened is that there is big instant fire at the opening place, and that's it . There is no pushing forward movement happening at all, is there anything i did wrong? by the way i used the butane as the fuel.

ivver Pas1933 months ago

It is happening because of too much fuel vapors in the bottle, you have to have right combination of fuel and air to get nice ignition.

BikeHacker3 months ago

Really cool!

tahuwahu12 months ago
Very cool - nice work ;)
Samuel kos1 year ago
I've made this and it so much fun thank you for posting this!
I absolutely love this launcher. It's simple, easy to make and FUN! This launcher inspired me to modify it and post an instructable of my design. Thank You!
Is it possible to use a lighter instead of a replacement barbecue igniter. Such as this:http://www.amazon.com/Calico-Brands-HF12CR-Black-Lighter/dp/B000UONR4M/ref=sr_1_11?ie=UTF8&qid=1366266006&sr=8-11&keywords=lighter
yes it is possible to use a gas lighter as a substitute
it is also possible to use perfume as a fuel
Halo 4 "Sticky Detonator!"
Great! Allow me to share my riff on this elegantly simple design. Throw in a PVC tee, grill igniter fits into the the rear, add a short piece of PVC for a pistol grip. I wouldn't recommend starting fluid, alcohol (70% and 90%) works as advertised.
rightangle.jpg
NightHawkInLight (author)  crispyjones1 year ago
Looks good!
damato321 year ago
I made this with two handles for a more gun-like design, per my kids' request (see picture attached). But we had difficulty getting it to ignite. I got it to work twice, but in both cases the blast was pretty big and I got singed a bit. I'll keep trying to get he right mix (atomizing is indeed key - we used 91% alcohol as shown). In the meantime, we decided to use a bottle half the size as the one shown in the video above. The bottle doesn't slide down much, but if fits perfectly and now we can blast these off pretty easily. I found the trick to be pouring about 1/2oz of alcohol into the bottle, then shaking it vigorously (with the cap off) and then pouring our all excess so that the bottle only has a slight coating of the alcohol. Thanks for sharing. This is one of the best Instructables projects we've done.
Alcohol Rocket Gun.jpg
NightHawkInLight (author)  damato321 year ago
Very cool. Since posting this instructible several people have mentioned the great idea of using another bottle that has been cut off and inserted over the pipe to act as a blast shield. Perhaps a 2 liter so it's plenty large to catch the flame and block any spray.
This is simple enough to make and awesome enough to be worth making!!! :)
I found a similar igniter in a gas water heater and used methylated spirits as the fuel.
It worked well :)
So we made one of these yesterday evening with a 'barrel' length of about 20" or so. We had a very difficult time getting it to fire with alcohol (we used 91% isopropanol) and only got one actual ignition.

Any tips to getting it to fire consistently with rubbing alcohol?

After our frustration, we switched over to propane + 1 liter coke bottle (stronger plastic than a water bottle). We just used a propane torch, put the nozzle in the bottle, give it 1 - 2 seconds of fuel, and it shot perfectly every time, at least until we broke the bottle.

But I still want to get it to fire more consistently via rubbing alcohol.
The key is to find the right amount of fuel. Too little or too much and it won't burn. Between trials be sure to blow fresh air into the bottle or there won't be enough oxygen to burn the fresh fuel. Once you find the amount you need it's just a matter of consistency.
The trick is to atomize the fuel. We did this by pouring a quarter tsp or so of fuel into a 24oz pop bottle and then spraying a few bursts of air into it with an air-compressor. Camp fuel is by far the best fuel I have found for this. Gasoline works but camp fuel smells better. Finally, a single wrap of electrical tape around the pipe and cram the bottle pretty hard onto it.

It is important that the bottle sticks onto the pipe because the explosive force is magnified under compression.

A nose cone and fins help a lot. Keep fins on the small side. Expect 30-40 shots out of a bottle before it must be retired.

We get launches 150' up and 400' distance.

Caution: Sometimes there is residual fuel and enough air to fire again. Discovered this indoors. Ooops.
Edgar1 year ago
Nice!
Voted, and a Link gone to this Blog.
http://faz-voce-mesmo.blogspot.pt/2013/04/autodesk-pala-partilhar-3d-cercas-mais.html
eljohn31 year ago
Great make! The only thing I would suggest is adding a disk of plastic or cardboard in front of the duct tape to divert the flaming exhaust and prevent scorched knuckles (basically a little launch pad).
fjr_scoot1 year ago
Almost every time I see a gas grill along the road that someone has thrown away, it's because the burner has corroded. The igniters are mostly still good. Just sayin': good source for igniters
flavrt1 year ago
Just speculating wildly, but it would also probably be best to not try this at home with acetone, gasoline, or over-proof rum, right?
NightHawkInLight (author)  flavrt1 year ago
Acetone would probably melt the bottle, gasoline would be difficult to find the right fuel/air mix for and would stink up the place, 140 or higher proof rum would work fine, if you didn't care to drink it.
quite a waste of rum, I would say :-)
I've done all sorts of bottle rockets over the years... denatured alcohol was best, next isopropyl is next. Gasoline burns too hot and the mixture is difficult to get, the bottles warp and melt. Acetone and MEK are also hot... and more explosive than burning... you want a burn that lasts for a few milliseconds but isn't too hot.

My favorite is a 3-liter bottle where the lid has two 1/8 (3mm) inch diameter holes drilled about 1/8 inch (3mm) apart. Use one tablespoon of fuel. Lay it at a slight incline OUTSIDE on cement. Light... about a 20" (50mm) fireball and 80 foot (24m) flight. You can stick the two probes into the holes... give yourself some distance... or your arm won't have much hair left.

Remember... don't do this at home... go to your friends home. :o)
I have been shooting bottle across my yard for kicks for some time now. I just use a lighter. But I get the best distance from Heat fuel treatment. I am going to make this project and I am expecting even a greater distance.
mbourhan1 year ago
neat
If the bottle had a little weight added, it would fly farther.
Have you considered sending a bottle to the moon with this?
mudfish1 year ago
wonderful
*votes
raypsi1 year ago
gr8 job and vblog I like to use disposable flash camera's guts. Have you tried finns and or nose cones, on the bottles? Nose cone to reduce the aerodynamic drap and finns to stabilize it in flight.
Range can be dramatically improved by adding fins and a nose cone.
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