In the previous step I stripped up one side, letting the ends of the strips overhang the center or keel line. In this video I am trimming off those ends so the keel line is straight and true.
First I transfer the center line to the outside of the strip using a little marking gauge made from some scrap plywood. The gauge extends the center line marked on the forms out to the top. I make a little pencil mark on the strips. I then connect these dots using a scrap strip clamped along the marks. After making sure the spline-strip is straight and true, I mark the line with a pencil.