I used my dimple dies, and proceeded to dimple all the top skin. 120�ntersunk was used for the forward spar holes. I click out the four thanks supports in place. Remember they are directional and only line up in one orientation. The tank supports was duburred on all four edges, as well as the holes. I gave it a coat of self etching primer on the contact side. I riveted the leading edge rivets,. Then I worked my way back one row at a time. I then proceeded to draw with a number 40 followed by a number 30 drill bit on the rear spar-Match drilling. I then proceeded to De Beer the top skin on both sides, as well as the rear spar both sides.