Kilwhang,
As always a concise and accurate description of the problem I saw as a young lad. I was at Colerne 72/3 when the Corrosion Control Team was formed. We had three shifts which allowed us to cover 7 day, 24 hour support in the quest to inspect and repair corrosion damaged lower wing planks. Though, I would argue that the corrosion problem did not necessarily result from water and Cladosporium Resinae (CR) in the fuel. I offer this as an example of why I believe that to be. Behind each engine, and below the dry bay, a titanium heat shield was fitted, to shield the aluminium skin from the hot jet efflux. After many inspections, and subsequent blending of the corrosion found within the tanks, we noticed that as we blended out the corrosion the area increased, and believed that the corrosion was not beginning on the surface of the wing planks, but within the material itself, and only being found as it "broke surface". As a result of that, we were tasked, on top of fuel tank inspection, to remove the plenum chamber from behind the engines, the heat shield and then inspect the skin under the dry bay. We found many examples of the same corrosion in those locations, including the head of an air grinder disappearing into the dry bay when attempting to blend a small patch of corrosion. The skin was simply rotten.
I believe that after I joined you at Akrotiri in late 73 a decision was made to replace the outer mainplanes, on the basis that the material used on the original wings was of sub standard quality. I certainly remember the strontium chromate cartridges being in the tanks in the 72/3 time frame so obviously attempts to counter the CR were well underway back then. I think that back then, all of us "tank rats" believed that the corrosion emanated from within the material, and not as penetration from surface corrosion. Hope that helps, I'm sure someone will have the "big picture".
Smudge
