At last, the new heavy duty .040 eyebrow skylight doublers are done. A very slight roll was added to each doubler before installation. The outside circle, upper roof contact edge of the doublers were sanded fairly round to minimize any tendency there might be to bend or chafe the roof skin at the outer edges of the much stiffer doubler. Compared to the .040 doublers, the .020 roof skin is pretty flimsy, so I wanted to take extra caution getting it firmly and evenly riveted down. Consequently, as shown in the first photo, in addition to liberal use of clecos, every hole was double clamped before riveting. The second photo shows the completed doublers, with virtually no bulging distortion of the lower edges now, as there had been before with the previous lightweight .020 doublers. About 11 hours of work in this redo job. Ouch. At least it's done and done right. Onward.