Arrange four 1/2-by-12-by-12-inch plywood boards in an upright square. Position the boards so they each touch two other boards to make a 12-1/2-by-12-1/2-inch square frame. Drill four holes through each board and into the end of the board which is adjacent to it for a total of 16 holes. Set 2-inch wood screws in each hole and securely tighten them to make the boards into a solid frame.
Set a 1/2-by-12-1/2-by-12-1/2-inch plywood board on top of the frame and fix the edges to line up perfectly with the frame. Drill holes every four inches down through this larger board, which is the rear board, and into the frame boards. Set 2-inch wood screws in the holes and tighten them down hard.
Flip the cabinet upside down and position another 1/2-by-12-1/2-by-12-1/2-inch plywood board on the frame. Slide two internal-mount cabinet hinges between this board, which is the cabinet door, and one of the frame boards. Remove or lift the door, if necessary, to find the best spaces to install the hinges against the frame board, and mark the location of the hinge's screw holes on the frame board. Drill the holes out and attach the hinge to the frame board with 1/2-inch wood screws. Repeat to add the door to the hinge.
Position the locking latch mechanism on the outside of the cabinet. Mark the location of the internal attachments on the door and frame board of the cabinet and remove the latch. Drill out the attachment points. Separate the door section of the latch from the frame board section. Set each section in place on their respective boards and slide their attachments through the drilled holes. Fasten them on the inside of the cabinet using the latch-specific attachment method of nuts, screws, etc. Lock the cabinet with a padlock.
Things You Will Need
- 1/2-by-12-by-12-inch plywood boards, 4
- 1/2-by-12-1/2-by-12-1/2-inch plywood boards, 2
- Drill bits
- 2-inch wood screws
- 2 internal-mount cabinet hinges
- Locking latch with internal attachments
- Add additional security to the cabinet by attaching 1/2-by-12-by-12-1/2-inch boards to the outside of the frame boards by screwing them to the cabinet from the inside. This prevents anyone from unscrewing the cabinet boards from the outside to open it.