I finally managed to try coating the PCB with epoxy resin. I wanted the circuit to be visible and, at the same time, protected so I thought epoxy would be a good idea.

The test wasn't a great success.
First of all, I expected a shiny smooth over but ended up being rough and not visually appetible. This is probably the result of my little experience handling the epoxy.  
And I also lost the button in the process. Despite paying attention not to cover the push-button, the resin still managed to sneak in, making it unusable. I had to remove it and fix it.

However, the coating adds some weight and gives a nice solid feeling. I will try again and maybe with a different material. If someone has any suggestion I'll be happy to know it.