Galvanization refers to the process of dipping steel and iron into a bath of zinc. The coating prevents the metal from corroding. Available flat or corrugated, the metal is typically used in industrial applications as ductwork, for troughs and feed pails, and as a roofing material. Decorative purposes include use as a backsplash in a kitchen or bathroom, and in perforated metal screens. Creating a tabletop with galvanized metal creates a post-industrial look suitable for casual rooms or outdoor use.
Use a circular saw with a wood cutting blade to cut the plywood to the desired size. Sand the edges smooth. Fill in any imperfections on what will become the top surface with wood putty. Let the wood putty cure for the length of time recommended by the manufacturer and sand it smooth.
Cut the galvanized metal to size with a jigsaw or circular saw fitted with a metal cutting blade. Measure the cut plywood and transfer that measurement to the galvanized metal. Use a framing square to make sure the lines are perfectly straight. Use a flat file to smooth out rough spots after the metal is cut.
Set the cut metal on the workbench and lay the plywood on top of it. Check to make sure the metal lines up perfectly. Use a pencil to mark any spots where the metal overlaps the edge of the plywood and use a flat file to smooth those spots to the right size.
Lay the plywood on the workbench with the finished side up. Brush on a thin layer of contact cement then brush a layer of contact cement on what will be the underside of the galvanized metal. Check the manufacturer's recommendation for how long to let the contact cement dry before proceeding. This is typically 10 to 15 minutes, depending on the temperature and humidity of the room. Test the contact cement by touching the surface. Your finger should not pick up any cement residue.
Line up the galvanized metal with the plywood without letting the surfaces touch. As soon as the surfaces touch, they will bond, so use extreme care lining them up. When you're confident the surfaces will match, set the metal on the plywood and press it into place. Work a J roller or a rolling pin across the surface to ensure that there are no air pockets.
Set a piece of outside corner molding along one edge of the tabletop. Outside corner molding will cover the sharp edge of the galvanized metal and form a slight raised lip around the table. Cut the molding to fit and draw a line on the table along the edge of the molding. Apply contact cement in the space between the edge of the table and the line. Apply it also on the inside of the corner molding and press it into place. Repeat with the other sides.