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Here are pictures and embedded videos of other people who have made pop pop boats--cool variations, too. Putt Putt Gallery.

Below is the introduction to making the kind of toy steam engine boat seen in the movie Ponyo. To go straight to the instructional video links, click here.

ENGINE (BOILER) PATTERN needed for Step 7 CLICK HERE (Do not re-size or "fit to page", and check the scale) Foam boat pattern here If you decide to make a 3-D boat the pattern for the hull is here and the deck and cabin is here.A print-friendly list of materials and tools is here.

The first time I saw a putt putt (aka pop pop) boat I couldn't believe my eyes! I must have gotten every science toy known to mankind when I was a kid: rockets, airplanes, slinkys, the bird that dunks its head in water, the junior chemistry set that I almost burned down the house with...I could name dozens. But it wasn't until I was an adult that I encountered a putt putt steam boat. It was chugging away in an outdoor market in Bangladesh-- in Southern Asia-- one of the poorest countries in the world. Made mostly from a recycled milk tin, it sounded like a tugboat and it really zipped fast--all powered by a little vegetable oil lamp. How could such a cool thing have existed without my knowing about it?

2 boats from Bangladesh, one uncovered to show the boiler. The bodies are made from old tin cans, which rusted over the decades, causing the dark patches.

Even more astonishing, I learned that putt putt boats (also called pop pop boats) were once very popular throughout the world in the first half of the 20th century. So why did they disappear? I guess tin toys and steam power seemed antiquated after World War II. Batteries and plastics were the exciting thing happening to toys!

Part of an entry from a 1933 science magazine.

Speaking for myself, I'm tired of plastic and batteries, especially in my kid's toys. I must not be alone. Old fashioned toys--including putt-putt boats are becoming popular once again. Science, model and toy catalogs offer stamped tin boats from Asian countries like India, Pakistan and China. You can pick up old ones on eBay.

A word about safety: The boat is surrounded by water and the steam engine cannot explode. Yes, the boats use a candle flame, so of course kids have to be supervised and not touch it. But let's put this in context: We annually challenge our young children to position their faces inches from multiple burning candles stuck into a giant pastry.

Excepting a few experimenters who soldered together engines, putt putt boats have always been something people bought rather than made. Even the boats in Bangladesh required some brass for the engine and solder to seal it. Over the last 15 years I have made hundreds of putt putt boats with one goal in mind: to develop a design such that anybody could make their own. At first I copied engines using brass shim stock, copper tubes and solder. Then I began using epoxy glue instead of solder, and disposable aluminum pie tins instead of brass. After years of slow evolution, I completely redesigned the engine to be made of a cut-up aluminum soda can and flexible plastic drinking straws. Now almost three hundred of my 8th grade students make it every year as a technology project.

You can make the body of the boat with a recycled, cut-up milk or juice carton, which is easy to cut, water-proof and paintable (although mine are not painted here). Or you make a simpler boat out of a recycled foam grocery tray. In either case the engine is the same, made from a cut-up aluminum soft drink can and drinking straws. The instructions for both the steam engine and the boat are HERE.. Gabriel from California sent me this wonderful picture of his daughter and her science fair project about pop pop boats. Below, in the tub, you can see the simple foam boat. You can see other people's projects (and add yours if you send a picture) in the GALLERY OF POP POP BOATS.

I should mention that there are actually two kinds of putt putt boat: the diaphragm kind I concentrate on in this site, and the looped copper tubing kind. Instructions for this design were in the Cub Scout handbooks from 1954 to 1977. The advantage of the copper tubing engine is the relative ease of construction, and you cannot wreck it with too much heat. The disadvantage of the coil design is that it is often slower and makes little or no noise. If you are interested in this type, click here.

The engine of this boat is simply a coil of copper tubing.

Here is a gallery of pictures people from around the world send me of putt-putt/ pop pop boat projects they they have made.

Here are some interesting related pop pop links. Perhaps the best, most encompassing web site is the Pop Pop Pages by Vance Bass.

Have you thought about making a giant pop pop boat? You're not alone--and I mean that in a good way.

Daryl of Canada is building some magnificent, powerful boats and I call this his Dr. Suess boat

The longer I experiment with putt putt boats, the clearer it becomes to me that I have only just scratched the surface. It is too much for one person to conduct all the development and experimentation that needs to be done for this project to reach its full potential. I am happy to have found a kindred spirit who has developed a see-into putt putt engine and gone a long way toward understanding why some engines work and others don't.

Another kindred spirit looked up putt putt boat patents and scanned them into PDF files.

And here is some amazing work by a retired Dutch professor in the Netherlands, including a pop pop powered Dutch wooden shoe!

There has been lots of pop pop activity in France, and a French engineer is carrying on the tradition.

Here is a link to a Google translated page a gentleman from Argentina doing interesting research into pop pop engines

Here is a nanotechnology device smaller than an ant that uses propulsion system similar to a pop pop engine, but it uses audio waves instead of a flame as the power source.

Here is an interesting article that describes pulsating heat pipes (PHP) which incorporate the same principles that make pop pop boats work.

Instructions for building a putt putt (pop pop) boat using a recycled beverage can and a milk or juice carton click here.


For explanations, activities and cool links related to putt putt boats click here or on the picture.

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I'd like to know how this project goes for you. I'm happy to answer questions about it. Feedback from you is an important way for me to know what works and what needs clarification.

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