Hi, Last week whilst drilling the back of my Carioca 656 a brown fibrous mushey goo cam out, oh dear!! rotten wood. The upshot was a complete strip out of the bed, ply wall, insulation and the replacement of 4 cross members and splicing in 4 peices of damaged timber. The source of the mositure ingress was the high level brake light. Whilst undertaking this work, inspecting the aluminium skin clear evidence showed a white powedery oxidisation had corroded through in several places, cleaned the area and filled and sprayed, so all is well, however, what elements would have caused this? is it possible that the damp wood caused some form of reaction with aluminium? Whats your thoughts? Cheers Ian ps if anyone need infor on what I did to repair, just mail.