Weird aluminum on endcaps?

[Ferroequine]

While stripping our '75 Safari (the project is being posted in this thread), I came across an odd observation.

After stripping, the curved aluminum on the rear end cap appears to have a different "mill" finish on it than the straight sections of the sides (and for that matter the flat piece in the back below the window).

As you can see in the picture, it didn't even come out as shiny right after stripping. Both sides had their plasticoat mostly intact, so there was no oxidization. Even when I tried to polish it, I can't get a good mirror finish on it like I can with the flat pieces. I haven't managed to get a good picture of it yet, but it reminds you a little bit of a tiny "orange peel" effect.

Has anyone seen this before? Does stretching the aluminum change the physical properties somewhat?

[till]

I wonder if it has anything to do with the strech forming process that is used to make the end cap segments???

[Silvertwinkie]

Till hit it right on...when they form the skins on the end caps, it does this. Your Airstream is 110% normal.

[Anon]

Originally Posted by Silvertwinkie

Till hit it right on...when they form the skins on the end caps, it does this. Your Airstream is 110% normal.

You are lucky if Eric is right! You are 10% more normal!

[3Ms75Argosy]

I must be 120% normal. Our Argosy, after stripping, I found 3-4 different mill works. The stretch panels also seem to be of heavier aluminum vs. the sides.

Looking good!
Marc