David, there was a discussion on this topic some threads ago. One thing that NOT to do is use any white or yellow wood glue. Seems that the glue will gas off and cause rust. Hide glue has some advantages. It does not gas off and does not creep.. To do metal: clean with denatured alcohol. Okay. get ready, I'm serious, rub garlic on the surface. I guess there are some acids or something in the garlic that will etch the metal. (At least it will keep the vampires out. Maybe Dracula had iron deficiency anemia). Then glue the felt.