One piece folding Bench and Picnic Table
Step 5. Hold the table / seat boards together
The tabletop boards and the seat boards need to be held together at the middle to stop wrapping and creating an uneven tabletop or seat.
One way of doing this:
Drill a 10 mm (⅜") hole widthways through the center of all the tabletop / seat boards and drill a countersink hole wherever there is a nut and washer to go.
Align the packers between the boards and run a 10 mm (⅜") threaded rod through all the holes. Add nuts and washers, tighten, and cut off any rod excess with a hacksaw.
The packers or spacers can be either washers, or thin strips of wood with holes drilled through them. (see picture).
How thick are the packers?
The overall tabletop width is 460 mm (18⅛"), and the overall seat width is 183 mm (7¼").
Evenly spread the tabletop boards and the seat boards over those widths respectively, and that will determine the gap between each board - hence the thickness of the required packers (spacers).