Wearing safety glasses, drill a 5/16-in. hole through the center of the vent cap and the pie plate. While you’re at it, drill a few small holes through the bottom of the pie plate to allow for water drainage.
Leave the vent cap and pie plate bare for an industrial look, or paint them to add a pop of color. I find that a latex-based exterior paint on top of primer adheres best to galvanized metal. Paint the vent cap and pie plate separately before assembling your feeder. Be sure to follow the instructions on your paint can and allow adequate drying time.