The framing for the transverse seats at bow, stern and midships is fairly simple. The plywood panels have timbers glued to them that serve as landings for the seat tops. The stiffeners under the seats are simply slotted or half-jointed and glued into those landing timbers and finished with the top surfaces flush.
|Framing of aft seat.|
The difficulty of this work stems from the fact that the seats have curvature both on plan and vertically. The seat front runs parallel to the seat landing stringer at mid-height of the hull side panel, so that stringer sets the shape in all directions. In the photo below, the lengths of string running across the boat serve to define the exact level for the seat stiffeners at the various points along the stringer.
|Side seat stiffeners slotted and glued into the inner face of the hull side stringer. The strings define the correct alignment for each stiffener.|
|Another view of the main cockpit with the string guide and seat stiffeners.|
The side seat stiffeners were cut to exact length and angle before gluing them in. The correct angle to cut off the inboard end can be measured at the intersection with the hull, it will be the same at both ends. If you prefer, you can cut the stiffeners slightly over-length and trim later. To do this, wait for the epoxy of the joints to the side stringer to be fully cured, then remove the screws that hold the guide string. Lay the seat top in place and mark each stiffener at the inner edge of the seat top. That will give you both the length and the angle to cut.
The intersections of the stiffeners with the longitudinal cleat that will join the seat front and top to each other is done with a halved-joint. The top half of the stiffener is cut away for the width of the cleat and the cleat has a slot cut into it of the same depth and the width of the stiffener. Then the stiffener ends are all glued into their respective slots at the same time that the cleat is glued in place.
|Longitudinal cleat glued to seat stiffeners with halved joints.|
|Halved joint, with end of stiffener notched and glued into cleat. The screw is temporary and will be removed once the glue has cured.|
|Seat fronts clamped to the work bench with the ends lifted to pre-bend the sheet. He has also applied the epoxy coatings while pre-bent, which will help to hold it to the curve.|