BULKHEADS and SCARF JOINT DETAILS
Truing up the edges of the center bulkheads. They will be bolted together later, with a 1/4" shim to allow clearance for sawing the boat in half.
Scarf joint preparation. Eight pieces of 1/4" plywood were screwed down to the workbench, each offset 2". A disc sander was used to rough out the plywood. The joints were finished with a belt sander. The plys in the wood are a good indicator of the accuracy of the joint. If the plys follow straight lines, and the lines are the same distance apart, the joint will be good.
The scarfed panels have been separated about 6" and screwed back down to the workbench. Plastic film is placed under each scarf joint, then thin epoxy resin applied to all joint surfaces. After curing, the joints are sanded lightly, and assembled using thickened epoxy. They are held in place with drywall screws, then covered with plastic film before advancing to the next panel. When all panels are bonded together, clamps or weights are placed over the joints to keep them closed. Don't use to much pressure, the joint will be weakened if all the epoxy is squeezed out. After a 24 hour cure, the panels are removed and the joint dressed with a belt sander. Notice the use of disposable gloves - you don't want to get this stuff on bare skin. Wearing a respirator is also a good idea when working with liquid resins. A dust mask should be worn when sanding cured resin.