Seat Framing & starboard berth

I began the installation of the starboard side berth and seats. The original plan calls for 1/2" plywood,  although I do have some leftover Birch from building the hull that could be used, it has been out in the elements for a few years under my carport. The result is some water staining and some mildew on the outer faces. The wood itself is perfectly sound, and would be fine if painted - but I am not wanting to paint the seat tops.

I decided to build the tops out of cedar, using a shiplap joints and some beefy framing underneath. Had I used the plywood, I still would have added the framing, as I am a hefty guy tipping the scales at just under 300 lbs, with some hefty friends. I don't want any sag in the seats, especially when crashing over swells or sleeping in the berth.

The purpose of the shiplap is to prevent possible warping, which wouldn't happen with plywood, but could occur with cedar planks. With the joints glued and screwed in place there should be little movement.

I installed 1 1/2 cedar framing, attached to the partial bulkheads using thickened epoxy and pocket hole screws. I know it may make a few cringe --- but I did use the exterior blue pocket screws and the Kreg jig. It made installing the framing a snap and should make for a very tight and strong enough joint since it is being covered with the 3/4" cedar.

I also installed the first of the wainscoting which helps to stiffen the centre supports.

I installed the framing and dry fitted the planks. The will be fastened using screws and thickened epoxy.

You can use hand-tools to create simple shiplap joints in the most simple of methods. You can also use a router table and rabber bit or a Dado stack on a table saw.

We used a stacked Dado blade on our table saw.

The ends and centre pieces had slightly different cuts,  but typically I alternated the rabbet - one side on the top and the other on the bottom on each board.