I had some trepidation about painting my hinges black (on both the coin door and the back door piano hinge), but I did some light coats...waited for them to dry, moved the mechanism (in this case, the lock) and after about 3 light coats, it seems to work fine with no bunching of the paint around the hinge ears...You will probably want to scuff it, or even get a brass lock, and use some good automotive etching primer...just a light coat, though.


Here you can see the hinge extended during paint.
AJ