Just curious, does anodizing aluminum make the surface a little more brittle or something? I noticed tonight that just the pressure of a cleco against the front wing spar (9A) is enough to leave a ring indented in the anodized surface. At first I thought it was just grime or something, but nope, it's an actual indentation. It doesn't seem to matter how gentle I am with the cleco. The other thing I noticed is that the anodized surface shatters in a star burst pattern around the rivet. I only noticed this on rib rivets set on the single thickness portion of the spar (no doubler).
I'm not worried about it, but just got me curious as to why this occurs, when it doesn't seem to happen on non-anodized material.
I'm not worried about it, but just got me curious as to why this occurs, when it doesn't seem to happen on non-anodized material.