Nic-a-date is acidic. It works by etching away the surface of the coin with acid, and the transition between the date-numerals and field on a worn cupronickel coin is slightly more vulnerable to acid attack.

Your coin has already been attacked by acid. Adding more acid will only make things worse.
Don't say "infinitely" when you mean "very"; otherwise, you'll have no word left when you want to talk about something really infinite. - C. S. Lewis