Gluing Metal to Wood

I'm making some wooden plaques with glued-on engraved metal plates. What glue should I use? Will it stick to the finish, or should I leave the area under the metal unfinished?
—Stephen Jeganathan, Singapore City, Singapore

For metal-to-wood glue-ups, your best bet will be epoxy, Stephen. Epoxy bonds wood to nearly anything. Before you apply finish, mask off an area slightly smaller than the metal plate to leave yourself an unfinished gluing surface. Then, scuff the back of the metal plate with 120-grit sandpaper to create a "tooth" for the epoxy to grab. After finishing, remove the tape and use a quick-set epoxy to bond the plate to the plaque.