# Candle Powered Hot Air Balloon

Build a candle powered hot air balloon using painter's plastic, balsa wood, and birthday candles.

## Step 1:

Cut the plastic and heat-seal the edges.

Layout your materials on a large sheet cardboard.

Pull out approximately 6 feet of the painter's plastic and cut it forming a sheet 9 x 6 ft. It's important to have plastic that is 1/2 mil (12 microns) or thinner. Thicker plastic is too heavy to fly.

Fold the sheet in half along the 9 ft side forming a two-ply sheet 4.5 x 6 ft. Use a hot knife to seal the two 4.5 ft edges. An electric hot knife makes this really easy, but it can also be done with an old metal knife heated over a flame.

Check your edges and correct any large holes. A few small holes won't cause problems.
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milesnorth8 months ago

I found a "xmas tree bag" and its got me thinking :-) Extra big, white, and infinitely inflatable :-) I can see myself out in sub zero temperatures making a hot air balloon already! Fun Fun Fun!

milesnorth8 months ago

SWEET!

imrational3 years ago
I use to make these out of tissue paper and balsa (with an aluminum foil cup to hold the fuel) when doing science lessons for elementary school kids. For the fuel, I'd recommend melting some vaseline and soaking a cottonball in it. Then put the cottonball in your fuel chamber/gondola. Inflate the balloon with a hair dryer and then light your cotton ball.
ali reza3 years ago
Hi
I'm a High school student .I'm work About the physics of Paper (lanterns)hot air balloon
Especially About (physics of) Form this Paper hot air balloon.

3 years ago
Oh, you can calculate the difference directly by PVM/R(1/T1-1/T2)=m1-m2
3 years ago
Hi! If you google Ideal gas law. That will tell you that PV=nRT. Where P is pressure, V is volume, n is number of moles, R is the gas constant and T is the temperature. All units in the SI-system. You can rewrite it to PV=m/M*RT. Where m is mass and M is the mole mass. Calculate how much a given volume weighs at the ambient condition. Normal values for P is 1.013 KPa and R=8.314 J/(K*mol). Next, estimate how hot the air can be (this could be quite tricky) and then calculate the weight of that air. The difference in mass should tell you how much lift there is
Dr.Bill3 years ago
We did this in 6th grade some 40 years ago. We used crossed kite sticks, Sterno in tinfoil cups one cup for each stick, and a black plastic garbage bag.
We flew it on an almost windless day. It went up and drifted away.
I am glad it didn't start a fire in the woods.
~bRiGhT_LiGhTs~3 years ago
To make this, do you have to use painters plastic ? Can't it be anything else other than painters plastic ? Can someone answer before Friday 16th, i need this for my science Project ! Tnx :D
javajunkie19764 years ago
How easy would it be to make a longer tube and power it with a Sterno can? I'm looking to build a hot-air airship for a steampunk design.
modded dollar store lighters would work i think. take off the metal cover and set the flame real high. tape it to the frame, tape the button down, then light it with another lighter. light fuel source and would go for a while. not very wind resistant tho, and probably a fire hazard......
4 years ago
yea it is a fire hazard cause if the flame is BIG and it burns for a while the valve starts to melt then it kinda just explodes.... its actually pretty cool to watch
njoneer5 years ago
A common dry-cleaning bag also works. It would let you skip this step.
4 years ago
yea my step mom is the manager of a dry cleaners so i can get thoes bags... but the problem is sealing the hole in the top of thoes bags because of where the hanger hook goes.
sbridges14 years ago
Hey thanks for the advise guys!! I wanted to do thease at my guide camp but i think we will but we'll teather them to the ground - on a long bit of string so we dont burn the site down!!

Also we'll do them on a 'small' scale with swing bin liners.

palog6 years ago
wouldn't birthday candles just melt really fast
5 years ago
thats the point. they burn fast. if you usedd a slower burning candel, it wouldnt generate enough heat to keep its own weight in the air
4 years ago
you could possibly use some jellied alcohol fuel like William Gurstelle suggests in Backyard Ballistics (only the best book ever)
ilpug4 years ago
would it be possible to put a bit of aluminum foil between or around the balsa wood and the candles to prevent the candles from burning the wood? or would that be too heavy?
hogey744 years ago
In Australia we call these UFOs and make em out of big garbage bags. I hear what people are saying about the fire risk so common sense is obviously needed. The answer is to only release em just after rain when the whole landscape is wet. Maybe not upwind of an oil refinery though. Some would say never do it but I say: let those UFOs fly!
A word to the wise here. I think it was around 1989 when a close friend was launching these about once a week or so just to hear the reaction on his police scanner. Well one night he launched one and it started a fire on a wood shake shingle roof about a mile away. He had no idea that this had happened as he didn't listen to the fire department frequencies. Just the police. Two more launches and they had his general area down to a three block radius. Two weeks later he was arrested and charged with Arson. He was sentenced to 4 years in prison. Police said that he was lucky that no one was killed or injured. If someone would have been killed he would have faced premeditated murder charges. If injured he would have faced attempted murder charges. Please do not launch these things as "UFOs". Keep them teathered or inside. Here in California it is illegal to release anything that is burning that is not short lived (like a bottle rocket or fireworks that leave the ground). These balloons are easily carried miles away still burning. If you are caught you could face up to a year in jail, and/or fines up to 5,000.00 for the first offence. Be Safe, Be Sure, and Be Happy Best, Smitty
4 years ago
How did your friend get 4 years in prison when towards the end, you said you could face up to 1 year in prison?

4 years ago
He was convicted of arson. Just getting cought doing this without burning something down can get you a year
4 years ago
haha wow thanks for the info
nerfer1924 years ago
we built these in my science club with trash bags, wire, and alcohol soaked cotton balls
_-MacGyver-_4 years ago
Anyone Remer the a-team Episode where Murdock and Hannibal used TARASSH BAGS, hair dryers, and lawnchairs to escape from prison.. Id liek to see someone do somethign similar :D
flamesami4 years ago
hmm...maybe you could make a "kid-safe", indoor version....
If you substituted the candles for a VERY small weight, and used a non-attached hair-dryer as a heat source, you could have several on the go at once, with no fire hazard...not as fun without fire though...
zilcho4 years ago
This could be an awesome windless kite
nutsandbolts_645 years ago
Can't you just suspend the candles with steel wire? Then suspend cardboard under the candles so that you won't need a large piece of cardboard lying around on the floor of your warehouse.
4 years ago
how i can attach candel to that........
4 years ago
Uh, it's wire, you can bend it everywhere. You can make a basket out of it or whatnot.
tinstructable5 years ago
If you didn't want to worry about it floating away, you could probably tie some fishing line on it.
FurtherThanTesla5 years ago
I recently got inrested in rigid zepplins, and wanted to build an RC non-rigid blimp< however, found myself lacking any helium. I figured i coul make a mini hot air balloon and put RC fans on it... i would have a flap controled by a servo to redirect heat from the flame to lift of lower the balloon...
thedogsaysocho5 years ago
So will one big candle jack up the ba
5 years ago
others may not have gotten this but I did good sir! +10 Internets for you!
hammertong5 years ago
I actually spotted and shot down (with a bb gun) one of these. Me & my brother thought we were crazy because we saw a fire just floating in the sky as the balloon slowly made its way towards us. Finally it got close enough to tell what it was, and to keep it from lighting anyone's house on fire we shot enough holes in it to bring it safely to the ground.
tech535 years ago
How about using chemical hand warmers in an aluminum pie tin or something? That should provide sufficient heat, and if you don't want to wait on the hot air you could fill the balloon with air using a hair dryer or a candle or something.
desotojohn5 years ago
This is DANGEROUS. In the 1960's, I remember newspaper accounts of this type of hot air baloon causing roof fires. Don't do this!
Whales5 years ago
I saw this a long time ago on one of those 90's kids science shows. That guy was crazy, but it oddly made me want to make it. good chance now. I'll let you know how things go!
ac1D5 years ago
You should try to power them with a wax fuel, I Don't know where to get them, but there is two include with this product: http://www.dealextreme.com/details.dx/sku.23486 and it make it fly really well.
FilAmFighter015 years ago
I saw this done before from the American Boys Handy Book, by Neally Croft just different materials. I like the new materials being used. BIG Caution is Balloons can start fires easly, carefull where you fly them!
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