Step 20: Dowel the deck beams to the gunwales
Now that the gunwales and deck beams are mating up flush, you are ready to dowel them firmly in place.
Each deck beam is currently held in place by 4 nails. Remove one nail, drill a 15/64 inch hole through the gunwale into the deck beam 2-1/4 inches deep and drive a quarter inch dowel into the hole until it bottoms out. Drill the holes so they come in at a slight angle in the horizontal plane. Then remove the next nail, drill and dowel and so on until you have replaced all 4 nails with dowels.