Fitting tank and trying to keep screw dimples from scratching up joint plate (nut plates in joint plate and dimpled as is the tank skin.) Using popsicle sticks as hold offs. Installed all bolts through spar - some not quite lined up - nut plates may / must have slipped slightly when drilling / riveting?? Installed 1/2 screws on tank skin to spar. Sucked skin down nicely.