Picture of Make a Boat Powered by Fire.
There are many ways to power a boat - propellers, aquajets, sails, powerful fans, turbo-jets, rockets, and pulse-jets.

There are few ways, though, as gentle and serene as the warmth of a candle.
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Step 1: What you Need.

Picture of What you Need.
Fire-boats need two important properties - to be light, and non-flammable.

My Clubbers used foil pie-tins as the hulls of the boats, kitchen foil as the sails and tea-lights to provide the heat.

We have, in the past, had success with normal-sized candles trimmed to only half an inch in height, or small clusters of birthday candles.

Step 2: Construction

Making a fire boat requires no specialised tools. In fact, it requires no tools at all.

A certain amount of intuition is also desirable.

Tear a piece of the foil to a suitable size, and fix it to the side of the pie-tin by scrunching the edge of the foil along the lip of the tray.

Curve the sail over the top of the boat. If it droops too far, add a crease or curve along the middle of the sail to ~~stop it drooping~~ add structural integrity.

Stand the candle in the boat, and you're ready to go.

The photos in this step are of the fire boats made by my Science-clubbers, before they took to the water. Some required tweaking, but they all worked to some degree.

Step 3: The Circular Fire Boat.

Picture of The Circular Fire Boat.
If the sail of a fire boat is not level, it will tend to spin.

This effect can be used on purpose as well - setting up two candles and sails facing in opposite directions on a circular metal lid created a boat that spun on the spot.

The clubbers had the idea that the idea could be used to make decorations which floated and spun in garden ponds or pools during a barbecue or garden party - the shiny foil sails would cast changing reflections around as the boats spun.

Step 4: Float Your Boat.

To see the fire boats working to their full potential, they need calm. Calm air and calm water.

We poured shallow pools of water into plastic trays and left them to settle. We also closed all the windows and doors to prevent draughts, and walked slowly so that the breeze of our passing wouldn't disturb the boats.

Place the boat at one end of the tray and light the candle.

As the candle burns, it heats the air around it. As you are probably aware, warm air rises. This is a convection current.

When the rising air hits the sail, it is deflected from its vertical path, which exerts a small, but real, force on the sail. Since the sail is fixed to the boat, the boat moves.

This video shows a couple of the boats my clubbers made:

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i made one too.home toys.it rained a good amount and at a place on our top floor of the house some water got stored.i tried it there and worked.thanks!good luck for your next instructables.
Kiteman (author)  argha halder2 years ago
Thank you.
lilchumy2 years ago
How exactly dose this work?
Kiteman (author)  lilchumy2 years ago
It's the deflection of convection currents - see step four.
makerboy1125 years ago
How on Earth do you think of this stuff?
Kiteman (author)  makerboy1125 years ago
I paid attention at school - this is a logical (but not very useful!) combination of heat transfer (convection) and Newtonian mechanics (action and reaction).

well when i saw the picture i automatically figured out how it worked
Oh dang, you're a cool kid now :O
80$man Kiteman3 years ago
Genius! I enjoyed this very much, good work! I have two comments:
Firstly, Newtonian mechanics (physics) coupled with fluid buoyancy effects (Archimedes) is causing the propultion. Convective heat transfer only causes fluid buoyancy (of the air) which has an action/reaction with the sail.
Secondly, could you consider rather funnelling the hot air into a converging tube that draws air under the boat allows the hot air to push against the water? This should provide a serious increase in propulsion! I have seen such a tube made from a hollow kettle element, but a crimped copper tube should suffice. Any thoughts on such improvements?
Kiteman (author)  80$man3 years ago
I haven't re-visited this project in a couple of years - feel free to use it as the basis of your own, improved fire-boat.
 Ahhh....I have a great imagination. Maybe I'll start paying attention now...
Jessierocks3 years ago
THANK YOU SOOOOOOOOOOOOO MUCH!!!!!! I'm doing this in school for science and I'm happy I went on this website instead of just youtube!!! :D
Kiteman (author)  Jessierocks3 years ago
You're welcome - remember, it's really important to stop all draughts in the area.
ilpug3 years ago
I think it would look just great if one made a ton of these and let them loose on a pond or pool at night. As long as they cleaned up afterwards of course.
merseyless6 years ago
i made on of these with the top of a jam jar and my homemade ultra candle! i put it in the kitchen sink and tried it out it worked ok and i only stopped it when the fuel in the candle started to boil and shot bits of it everywhere so i had a fireball in the sink with my alfoil starting to disintergrate. so i blew it out and decided never to use the candle again. lol good times... good times...
what super candle??? if its different from a rglar candle you should put it on this website
homemade candle... but the fuel caught on fire and boiled... not the best thing to have in you're sink.
wakojako6 years ago
wakojako6 years ago
knektek6 years ago
you could have a weight on one side, that will make the boat move, instead of using those 'ugly' sails, apart from that GREAT design!
Kiteman (author)  knektek6 years ago
If you read it, the sails are the whole point...
panzer7 years ago
OMG *light goes on above head* i've got an idea!!!!!!!!! OMG

i will post my idea soooon, cuz u gave me the best idea ever!!!!! and i have everything that is needed, cause its so simple, YES!!!!!! ha ha, thanks

greatttt instructable!
Kiteman (author)  panzer7 years ago
You're welcome.

Drop me a PM when you post it...
panzer Kiteman7 years ago
what's a PM???? sorry, i'm new to this....
Kiteman (author)  panzer7 years ago
PM = Private Message.

Click on a member's name, and you will go to their member space.

On the left, you will see their avatar, with a button beneath, "private message me". Use that to send messages you don't want to be seen by the rest of the site.
panzer Kiteman7 years ago
alright then, i don't know when i'll have it by, but prolly sometime this week!
give me a heads up too
Kiteman (author)  panzer7 years ago
Cool, I look forward to it.
me too!
maurice19936 years ago
hey! salutations for you all! I am new round here, ain't two weeks I visit this site, and this site it's incredible!!! One classamate mine has a idea almost similar, he use a soda can, made a few holes by the base, and in the top, he put two empty pens, and this pens to the rear end of the boat, under the water, and he use about three candles to made the fire. this isn't a convectional boat too? as the fire heat up the air into the canister, these hot air flow to the pens to outside the boat, creating the same efect? and that pop-pop-pop, yeap, the steam engine. (may the project of my classmate was a fusion of this two, like an hibrid?) sorry if my english is so poor, I'm still learning these language, I live in brasil :P
Kiteman (author)  maurice19936 years ago
That sounds interesting. Maybe a photo?
I don't have a photo because isn't my project, and the times from their science fair, I do not had a camera... but I can try to make one to share.
like this?


you will need to scroll way down the page but is that the general concept?
yeah, it's like that boat with the candle inside, but, when that boat have a elevation in the top, my matte's boat had a tube(like a pen) to irect the hot air flow to the end bottom of the boat... under the water...
I'm not quite sure what maurice1993 was trying to say, but the "pop-pop-pop" reminded me of 'pop-pop' boats. Have you ever heard of them? If so could you explain how they work for me please? ZZZZ
Kiteman (author)  zoltzerino6 years ago
Put briefly, the candle's heat boils a small volume of water and squirts it out the back. The steam hits the cold water outside the boat and condenses, which pulls water back into the boiler. The repeating cycle drives the boat and makes the pop-pop sound.
Yep, sounds like a pop pop to me... ZZZZ
thepelton6 years ago
I recall seeing a boat that you could make when I was a child that involved a candle and a copper tube attached to a piece of wood.
junits156 years ago
build like a giant fire in the tin and watch it rocket accross (if the tinfoil dosnt melt first! XD
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