I 3D printed the parts for this pop pop boat from Thingiverse (YosemiteSam) for a little rainy day family fun while on vacation at Lake Gaston, North Carolina. The boat worked great to our pleasant surprise. Two nickels need to be placed in the slots at the stern for balance and added engine noise. Parts printed with PLA held up to the heat with no damage and their dimensions fit the straws better than prints with ABS.

3D printed parts by YosemiteSam https://www.thingiverse.com/thing:913528

5mm Straws: https://www.amazon.com/dp/B087NFPSCJ/...

Heavy Duty Aluminum Foil: https://www.amazon.com/dp/B00M8ZEAW4/...

Tea candle https://www.amazon.com/dp/B019O4SB58/...

X-Acto knife: https://smile.amazon.com/dp/B005KRSWM...

Exhaust sealer (high temperature): https://www.amazon.com/dp/B0002UEOPA/...

Super glue: https://smile.amazon.com/dp/B003Y49R7...

Sandpaper: https://smile.amazon.com/dp/B0084LZYV...

Acetone: https://smile.amazon.com/dp/B004KJ7AG...

Two nickels (ballast and engine noise)

Enjoy!
Jim