What if you submerged a raspberry pi in epoxy except for the ports?

you get a poted raspi?

Raspberry Pi Preserves

You'd get a cooling and thus stability problem unless you underclock the system considerably.

Otherwise, coating populated PCBs is common for applications that require moisture resistance.

Piepoxy

I wasn't really being serious, but thanks :) I might try it on a Raspberry Pi zero

@TheOneFuzzyBit my car has coil fully covered in epoxy. It's fully humidity resistant, but at the same time it's unrepairable.
Your rpi will be fine, but you'd better attach a good heatsink to the cpu before applying epoxy. And don't cover the heatsink with epoxy ;)