I'm not sure just how you enter this into a calculator, when your trying to be the smartest person in the room (Earth to steve86, your not even close) I have no idea just how much paint is used in the Tail-Section, where I worked in the Everett (Washington state) Plant (40-41 bldg) (at the time, it was said, you could tear off the roof, put the Seattle King-Dome in the building, put the roof back on, and still have room for parking.) we didn't paint any of those sections. We only painted the "vertical stabilizer-part," that moved, so as to turn the plane left /right directions.
"vertical stabilizer-part," one man operation to paint, approx. 7 gallons (one part paint, one part hardener.) PS, the only reason this sticks in my head, was you would use the "ONLY" 5-gal spray-pot, otherwise it was "20-gal spray-pots," that could be filled to 22 gal. capacity. Had the little "AIR-MOTOR'S" to constantly stir the paint, inside the pot(s.) We cried and moaned, begged for bigger pot's. Never got them, at least for the 5 yr's I worked their. In truth, I don't even know if a bigger spray pot was available, now that I think about it. But we sure wanted one.
I worked in what was called the "Body-Section & Detail shop." Now, let's say on a 747, you had 300 seat's, all had say a cover plate for a ash-try, needing paint.
Bingo, you got it, that's 300 PAINTED ASH-TRY COVER PLATES.
If it help's, you only use approx. 1.5 gal paint, to paint/refinish the Pilot's & Co-Pilot's console(s) and "seat-bracket(s.)"
So, steve86 just how many THOSANDS of parts on a 747 require painting, inquiring minds would like to know.
I think you are a bit mentally unbalanced these days but best wishes from a fellow Washingtonian (Eastern WA).