PLA can absorb water. I use epoxy to help seal the PLA plastic. I have seen people run them without it though. I have never tried without epoxy so I am not sure if it will last or not.
I updated the links. Sorry for the delay on that. I will also paste the link here. cults3d.com/en/3d-model/game/1-10th-scale-rc-airboat-3d-printer-files-instructions
