Pcb help

HI,just made my first arduino pcb's.They turned out quite well except um, after 7-10 days now the whole copper side has started going black. (1)Is there a way to prevent it.I hv seen green coating on professional ones.Is there a cheap alternative to elongate their life? (2)Also drilling turned out be a hell of an affair.I dont wanna buy a drill press and working with my hand drill to drill them was a nightmare.Any solutions? Thanks!

Side note :- I didn't want to create a new post to spam but an out of context question.I am making a biped and I bought some servos.They had with them a main horn screw but no side horn screws(the real tiny ones) .Any substitutes?

1 2 side

1) Really cheap? Go with clear nail polish. Not as cheap but awesome? Liquid-tin.

2) If by nightmare you mean the accuracy of the holes I suggest using a centerpunch to give the drill bit a depression to get started in. It will help reduce the wander in the beginning. If by nightmare you mean the time consumption I recommend a rotary tool like a Dremel or Black& Decker and pair it with a Milescraft Tool Stand. I couldn’t live without mine.

Side note (yes a new post would be better): I’m guessing by the description “real tiny ones” that you’re dealing with the small blue 9g servos. Use #0 screws for attaching things to the servo horns. No modifications will be necessary.