Brian,
As usual, I'm a day late and a dollar short, apologies for being tardy for this discussion. Eric Fisher (of Aero-Rarities) and I havebeen corresponding this last week on just this subject: aluminum dope finishes and reflectivity. Long story made very, very short: it's almost as if aluminum-doped fabric almost has a "grain" to it so-to-speak, and can result in some strange optical illusions. In my case, it was the last section of the underside of the fuselage looking dark, the part on which the tail-skid cover goes. We've come to the conclusion that, despite them appearing very dark in many photos, but yet just like the surrounding alu-doped surfaces in others, it's a function of the reflectivity.
Now, how I'm approaching this on my builds is a big experiment at Chez Dickinson right now.
Warren
