It will take a couple of hours for it to harden but it is best to leave it over night. Once it is completely dried flip it over. Nail polish remover will help remove expanding foam if you act quickly. On Reddit, the talented cosplayer showed off her take on the popular New 52 Batgirl ensemble. A woman dressed as comic book character Diva from StormWatch on Friday. Ghostbusters game now at Atari?