Make a pop pop boat Follow FizzicsEd 150 Science Experiments: Comments 0 You will need: One 600 mL plastic soft drink bottle, cut in half lengthways using scissors. One tea-light candle. Matches or cigarette lighter. 25 cm of 6 mm copper tubing. BBQ Firelighter. We’ve found this to be far more reliable than the candle-powered versions. One tub of water. Hacksaw to cut the tubing to size A bench vice-to hold the tubing safely. A drill press with 3.5 mm drill bit-to clean out the holes. Two hand pliers to bend the copper tube into shape. Safety goggles Adult supervision! Written by Fizzics Education. Reviewed by Ben Newsome CF. Cite this experiment Copyright Notice Instruction Video Instruction 1 Cut your soft drink bottle in half lengthways. 2 Fit your copper tube in the bench vice and use a hacksaw to cut a length of 6mm copper tubing to a 25cm length. The ends of the copper will need a small drill bit to clean out the metal burrs that can cover the opening of the tubing (we used a drill press for safety). 3 Use the pliers to bend the copper pipe into the shape as shown below. 4 Separate the tea-light candle from its metal holder and arrange the materials in the boat as shown below. The candle acts as a counterweight for the copper tubing at the back of the boat. 5 Cut notches in the bottle so that the tubing can rest in the back of the boat. 6 Add the firelighter the metal container and you’ve set the boat up! Now put in some water, light the firelighter and watch it go! You may need to pre-fill the tubing with water to speed the process up. Try filling the tube and then pouring most of the water out so the inside of the tube is damp. If there are balance issues you can sort this out with additional weights (use metal nuts if needed). Make sure that the tubing is bent so that it can reach the surface of the water. You may need to make slight adjustments to this design but in essence, this is a robust science experiment that kids will love to build. Enjoy! 7 Get the Unit of Work on Heat Energy here! What actually is heat? How does heat move through different materials? How does heat change the properties of materials and more! Includes cross-curricular teaching ideas, student quizzes, a sample marking rubric, scope & sequences & more 8 School science visits since 2004! – Curriculum-linked & award-winning incursions. – Over 40 primary & high school programs to choose from. – Designed by experienced educators. – Over 2 million students reached. – Face to face incursions & online programs available. – Early learning centre visits too! 9 Online courses for teachers & parents – Help students learn how science really works Why Does This Happen? How a Pop Pop Boat Works The science of a pop pop boat is all about heat and pressure. The firelighter flame heats the water trapped inside the copper tubing until it reaches its boiling point. Because water expands massively when it turns into steam, it is forced out of the tubes at high velocity. This expulsion of heated water and steam produces the thrust needed to send the boat forwards. This is a perfect demonstration of Newton’s 3rd Law of Motion, which states that “for every action, there is an equal and opposite reaction.” As the water is pushed out the back, the boat is pushed forward! Once the steam is expelled, it creates a temporary low-pressure area (a partial vacuum) within the tubing coil. Any remaining steam inside the coil quickly condenses back into liquid water, further reducing the internal pressure. Because the air pressure pushing down on the surface of the tub is now higher than the pressure inside the tube, fresh water is sucked back into the copper tubing. This water is then heated, flash-evaporates into steam, and the cycle repeats—creating the characteristic “pop pop” sound! Variables to test Find out more on variables here. Tubing Diameter Try using different diameter copper tubing. Does a wider tube produce a louder “pop” or a faster boat? Coil Configuration If you don’t coil the tubing and keep it straight instead, does the boat still work? Consider how the coil helps to trap the heat from the flame. Heat Intensity What happens if you use a larger flame or two firelighters? Does the increased heat increase the frequency of the steam pulses? âś… Reviewed: April 5, 2026 APA 7 Citation: Fizzics Education. (2018). Make a pop pop boat. https://www.fizzicseducation.com.au/150-science-experiments/heat-experiments/make-a-pop-pop-boat-2/ Copy APA Citation Reviewer This resource was last reviewed for scientific accuracy on April 5, 2026. Ben Newsome CF is the recipient of the 2023 UTS Chancellor’s Award for Excellence and a Churchill Fellow. He is a global leader in science communication and the founder of Fizzics Education. Learn more! From liquid nitrogen shows to hot & cold workshops, we’ve got your unit on properties of materials covered! Get in touch with FizzicsEd to find out how we can work with your class. Hot & Cold Workshop Years 1 to 6 Maximum 30 students School workshop (NSW & VIC) 60 or 90 minutes Online Class Available Read More Enquire Now Rubber band powered boat $10.95 excl. GST View Details Add to Cart Trustpilot STEM Full Day Accelerator - Primary Designed from real classroom experiences, this modular day helps you create consistently effective science learning that directly address the new curriculum with easily accessible and cost-effective materials. Read More Enquire Now Be Amazing! How to teach science, the way primary kids love. $29.95 excl. GST View Details Add to Cart Trustpilot
Fit your copper tube in the bench vice and use a hacksaw to cut a length of 6mm copper tubing to a 25cm length. The ends of the copper will need a small drill bit to clean out the metal burrs that can cover the opening of the tubing (we used a drill press for safety).
Separate the tea-light candle from its metal holder and arrange the materials in the boat as shown below. The candle acts as a counterweight for the copper tubing at the back of the boat.
Add the firelighter the metal container and you’ve set the boat up! Now put in some water, light the firelighter and watch it go! You may need to pre-fill the tubing with water to speed the process up. Try filling the tube and then pouring most of the water out so the inside of the tube is damp. If there are balance issues you can sort this out with additional weights (use metal nuts if needed). Make sure that the tubing is bent so that it can reach the surface of the water. You may need to make slight adjustments to this design but in essence, this is a robust science experiment that kids will love to build. Enjoy!
Get the Unit of Work on Heat Energy here! What actually is heat? How does heat move through different materials? How does heat change the properties of materials and more! Includes cross-curricular teaching ideas, student quizzes, a sample marking rubric, scope & sequences & more
School science visits since 2004! – Curriculum-linked & award-winning incursions. – Over 40 primary & high school programs to choose from. – Designed by experienced educators. – Over 2 million students reached. – Face to face incursions & online programs available. – Early learning centre visits too!
From liquid nitrogen shows to hot & cold workshops, we’ve got your unit on properties of materials covered! Get in touch with FizzicsEd to find out how we can work with your class.
Hot & Cold Workshop Years 1 to 6 Maximum 30 students School workshop (NSW & VIC) 60 or 90 minutes Online Class Available Read More Enquire Now
STEM Full Day Accelerator - Primary Designed from real classroom experiences, this modular day helps you create consistently effective science learning that directly address the new curriculum with easily accessible and cost-effective materials. Read More Enquire Now
Designed from real classroom experiences, this modular day helps you create consistently effective science learning that directly address the new curriculum with easily accessible and cost-effective materials.
Be Amazing! How to teach science, the way primary kids love. $29.95 excl. GST View Details Add to Cart Trustpilot
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