Sadly, this seems to be pretty much the standard, especially for first time buyers and / or people who know nothing about airplanes. So far, I heard way more stories like yours (and much worse) than reports that the plane needed nothing and was as expected.
I am really glad that we decided to get this 172 instead of a Mooney M20C or a PA-24, which I would have personally preferred. We thought that it would be wise to gain experience as owners with a basic plane, in good condition, which we could easily afford, including possibly necessary repairs. I would be a lot more nervous, if we would have a more expensive, complex aircraft sitting in the hangar, with more things to break, for which we spent all of our savings. Or, even worse, if all the savings would be gone and we would additionally have to pay off a loan for the plane.
No. That's why I asked them to look for corrosion. The plane sat there for only 6 years, I therefore did not consider it to be a 'real' Florida plane.
Well, I wasn't talking about a law suit, but only about legal consultation. Frankly, even though I am not familiar with the US legal system, I agree with you that a law suit would not go anywhere. We bought it from the seller 'as is', he made no promises regarding its condition. I also agree with you regarding the 'paid opinion' and the Cessna Center. Their opinion was worth crap, I however doubt that this makes them liable for possibly bad decisions based on it.
To have a plane sitting outside, without even a roof to protect it from the elements, is IMHO plane-torture and should be prohibited.
I believe that we have already learned some very valuable lessons. Besides of that I now have a significantly better understanding of what to look for mechanically and in the aircraft's paperwork, I also learned that our next plane will certainly come from a dryer area and that I will participate in person in the pre-buy inspection. As 'dry area' also means long distance purchase for us, the logistics will be more complicated, but most likely worthwhile the efforts.
Regarding our own plane, I have good news. We removed all inspection covers also also inspected the wing and wingstrut bolts, as well as the areas surrounding them. Gladly, we found lots of greasy goo but no corrosion in these critical areas (1st and 2nd picture). The tail also looked good (3rd picture)
We however found some weird stuff in the wings and the tailfeathers (as initially posted). It turned out that the areas which looked like moss and what I thought was corrosion, were actually some kind of coating. We could scrape it of with our fingernails, some of it chipped off in big chunks (picture 4, front and rear of two of them). Picture 5 and 6 show the same area, before and after I chipped off the 'stuff' with my fingernails. Gladly, it was apparently only applied in areas which could be reached with a rattle-can through inspection covers or other existing openings, what also means, that they can be reached with a cleaning pad. Underneath the 'stuff', the metal looked good and had, like in the untreated areas, only very light corrosion, which can be, according to our A&P, easily be stopped with CorrosionX. Picture 7 shows such a untreated section of the wing. Actually, everything looked pretty much the same - the mossy stuff in the vicinity of the openings and good metal, with very light corrosion on it everywhere else.
We will now clean the accessible areas, remove the old coating and then have the plane soaked in CorrosionX.
I am really happy about this outcome and that we do not have a serious corrosion issue.
However, this does not change my disappointment about the Cessna Center - the old, mossy coating and the beginning corrosion should have been a part of the pre-buy report.