that darker colour, could that be a sign of a crack that's been there for a while?
Yeah, the aluminium is exposed to air and stuff. Fresh stuff isn't so dark. Crack was there a while. Maybe they'd taken a knock at some point or something sharp run across it?
Yeah, the aluminium is exposed to air and stuff. Fresh stuff isn't so dark. Crack was there a while. Maybe they'd taken a knock at some point or something sharp run across it?