No, I didn't take up a musical instrument. Fluting is the process of crimping the rib flanges to straighten them. When the ribs are stamped out of the aluminum stock they usually come out with a bend. Notice how the rib in Image 1 is bowed up away from the table top. After fluting with the special tool the rib lays flat (Image 3.)
Next I think I will test install all the ribs to the left spar and number them. Still have to deburr the tiny little nooks and crannies in each rib, and all 174 lightening holes. Waiting for the 1" Scotchbrite wheels for that chore. Probably no more work until Monday.
