After ensuring the wing was straight and true, I started to layout the long rivet lines on the spars. Each spar is almost 15' long and visually draws your eye. So I really wanted a straight rivet line. Additionally the spar you will drill and rivet to is behind the skin. So not only do you need a straight line, it must be straight on the correct plane (no pun intended) or down the middle of the spar flange.
I decide to use taut lines to indicate the rivet line and a rivet fan to ensure even rivet spacing.
