Dear all, please, I would kindly ask you for a help - does anybody know / have pictures that could show what panels in NMF could have a different shades on B-17G?
Thanks & regards, erni
For the most part the skin panels on the B-17 will look the same since they are the same aluminum alloy, except in a few places like around the superchargers on the bottom of the engine nacelles (due to the use of a different alloy with slightly higher temperature resistance) and some parts of the engine cowls and the leading edge of the nacelles just behind the cowl flaps (where the heating and cooling cycle from the engine caused more rapid oxidation) which on operational aircraft would usually look slightly darker due to the decreased reflectance.
In general the skin panels made out of the same alloy of aluminum and applied to the aircraft at the same time will look very similar, but there will be very slight differences - due either to differing oxidation levels on the surface due to exposure to the sun and elements, replacement of the skin sections with new panels (generally brighter than the original panels), or both.
If you have not already done so take a look at this site: "Getty Images" There are a few images of bare metal B-17s that show some of the differences in panel shading/reflectance.
Also, maybe try typing alamy+B-17 in the search field of your browser, as they also appear to have a few images of bare metal B-17s.
Ideally you need the aircraft's Structural Repair Manual (or equivalent). On some types, there is indeed a 'map', showing material specs, thicknesses etc in these manuals.