While working outdoors around the yard and garden, you may need any variety of hand tools, bags of soil or fertilizer, or planters. With all of these supplies lying around, you can find your work space quite cluttered. To clean up the area where you keep your supplies, you may find it useful to make your own heavy-duty plywood storage box. Once your box is constructed, you can store as many items as will fit to have them close at hand.
Stand up each of your 18-by-24 pieces of plywood to be the front and back of your box. Slip an 18-inch-square board between the front and back pieces to form the sides of the box. Make the edges flush and attach with screws spaced every 6 inches.
Place a 20-inch 1-by-3 board along the top and bottom edges of both of the side pieces. Make the boards flush and screw two screws into each end of the boards. Put a 13-inch 1-by-3 board vertically along each side of the plywood sides to complete a frame. Screw two screws into each end of the 13-inch boards.
Use 26-inch 1-by-3 boards to form the top and bottom of frames on the front and back of the box and use two screws on each end to secure. Place the remaining 13-inch boards vertically to form the sides of the frames on both the front and back and screw into place with two screws on each end.
Place the 20-by-24-inch plywood piece over the entire unit and align to make the edges flush. Screw through the 20-by-24 piece every 6 inches to attach. Flip the box over to let this piece of plywood become the bottom of the box.
Set the 22-by-26-inch plywood piece on a flat surface and frame it like you did with the sides, front and back using a 26-inch 1-by-3 board on the top and bottom and 16-inch 1-by-3 boards on the sides. Screw two screws into each end of the boards to secure the frame and create the lid of your box.
Place the top over the box and align the edges. Place each of your hinges 6 inches in from the sides. Use screws to attach the hinges through the designated holes in the metal hinge to both the lid of the box and the back of the box.
Sand over the plywood box with sandpaper to make the wood as smooth as possible. Apply a wood sealant following the manufacturer's instructions and give the box sufficient time to dry before storing any of your tools or supplies inside it.