Hi all - Newbie here. I am trying to restore some stamped tin ceiling tiles. They have two layers of paint which have been very slow in coming off. I'm using a metal paint scraper as a plastic putty knife wasn't strong enough. I have a couple questions: 1) Can I 'wash' the tiles? They're pretty dirty, especially the backs. Black, soot-like stuff all over them. I'm worried the water will further rust the tiles but am also wondering if getting the paint wet will make taking it off easier. 2) I'm not sure if I want to repaint the tiles. If I just want to keep the original patina but want to seal the backs, I have to use an oil-based paint, correct? I heard that latex paint will rust them. Any tips will be welcomed. Also - I'm not restoring them to be reinstalled as a ceiling. Just as decorations. Thanks very much for your help!!