Hot snot gets icky with time, rather use a conformal coating; they're available in spray-form as well (e.g. CRC Urethan or Plastik 70). That being said FR4 is a

Hot snot gets icky with time, rather use a conformal coating; they're available in spray-form as well (e.g. CRC Urethan or Plastik 70). That being said FR4 is a really tough material and it's quite difficult to pry SMD parts off.