Laminating the deck carlins from two thin off-cut strips of wood. They should go in place easier this way and be stronger than single pieces by themselves. The only glue we're using in the kayaks is for the scarfs in the ribs to bypass knots and here in the laminated carlins.
I made a simple jig/form for the deck carlins by measuring out the frames from their centerlines and marking off where the carlin notches fall. Then I tacked in some nails and bent a strip of wood around them, marking the curve with a pencil. I then screwed down blocks of wood at each contact point along the frame, at the correct angle (lined up with the pencil marks).
An old closet door makes a great work surface.