Create a sandpaper storage cabinet
Cabinet manufacturers design their wall units to accept one or sometimes two shelves, but you may want more than that for shop storage. Ready-to-assemble (RTA) cabinets that disassemble quickly give you the easiest opportunities to add more shelves. But any cabinet wide enough to accept a drill and bit can be modified to add enough shelves to create a sandpaper center.
To disassemble RTA cabinets like the one shown, first remove the screws attaching the back and slide the back free of the case. Then loosen the fasteners holding the sides to the top and bottom and the face frame to the case.
Cut a perforated-hardboard drilling guide to fit between the top and bottom dadoes in the cabinet sides. Clamp the guide to the cabinet side and drill shelf-pin holes 1″ apart along one edge of the cabinet side, as shown below. Repeat for the opposite edge and other cabinet side.
Reassemble the cabinet except for the back. Cut additional shelves and insert shelf pins, slide the new shelves in from behind, and replace the back.