It's a PCB that will be inside my CNC controller box. I guess I want to last as long as possible and also want to make sure there's no short anywhere otherwise the magic smoke will kill a lot of components... PC, CNC etc. Plus it's a CNC, so I want to ensure there's signal integrity to make sure it doesn't do anything unexpected.
I'm just a bit confused since all coatings - tin, nickel/gold etc they all have a shelf life so it seems there's no solution to protect a PCB, they all just wither with time.