I choose Frame E as the first frame to be done. I fixed my drawn 1:1 plan on the workbench. The planed Douglas fir slats are cut to size, halved joint to strengthen the connection and then rounded on the insides of the frame with the router. This saves me time later when I have to sand it. The slats where glued with epoxy and fixed with clamps to the workbench while curing. Then the plywood gussets where glued and screwed to the joints. Finally I filled the cavities of the joints / plywood gussets with Styrodur and all corners with a microballon thickened epoxy putty. All together it took me approximately 30 hours of work including wood cutting. Later before mounting the frames on to the jig, I will put on 2 epoxy coatings.

Lateral view to the douglas fir joinery on the starboard top corner of frame E.