Cut the remainder of the 1X3 into 3 inch long pieces (you'll need four of them) for cleats.
(Kayaks are about 30 inches wide) and this rack will let you mount two, side by side, right side up or upside down...
Once the 1X6 are cut to length, mark and cut two 24 inch radius curves in in each one keeping at least three inches of material at the thinest point of the curve.
The remaining 1X6 will be cut to lenght after the supports are assembled and the length with be determined by the length of your roof racks. (See the Assemply step...)
Cut each pool noodle in half.
Continue reading this ONLY after you have have completed the "Fitting" step...
Now the you have your kayak support racks in place, you have your measurment to cut the center board (the remaining 1X6).
Cut it to the length needed for your roof racks and bore two holes in this board near the ends and near the middle of the width of board.