Printed in Makergeeks PETG for temperature resistance. Harbor Freight red RTV was used to glue a piece of Reynolds aluminum foil to the motor and the straws used are some VERY cheap Dollar Tree bendy straws. The quality on the straws is inconsistent. The straws were glued to the engine with Super Glue brand "Fix-All Adhesive" also purchased at Dollar Tree. I suspect the "Fix-All Adhesive" is just... Rubber cement.
It works! It works quite well too. I suspect it would work a little better if the engine's ports were located at the back, instead of center (It's hard to remove all of the air in the engine if the ports are located in a way that traps air when the engine is oriented in a way to fill it with a faucet/spigot).
I love this design and I'm actually excited to potentially try making more, or larger pop pop boats using 3D printing.
Translucent Orange and HD Smoke
Boat was only 15% infill, engine is 100%. I was trying to get it as optically clear as I could, and it worked for the most part. You can see the water boil in the engine and straws, which is really fun.