Corrosion on outer surfaces

[chrisk]

I went to look at a plane this last weekend. It was a very nice plane, but it had a few spots where the paint was missing and the skin was exposed. And on the exposed areas, there was white powdery corrosion. Some on the tail area, and some on the belly. I was wondering if this is normal, and something to be concerned with? The plane was supposed to have been hangered most of its life.

[rbridges]

I don't care what the owner tells you, I'd have it opened up and inspected if your serious about purchasing it. I believe the surface corrosion can be addressed easily, but I'd be worried about internal stuff that you can't see. Being hangared "most" of its life can still mean several years that it wasn't.

IMO, corrosion has the potential to be the most catastrophic thing for these planes.

[carusoam]

On my 65 C paint maintenance was often done at annual. A spot here a spot there.

Small spots of corrosion are expected. Taking care of it can be expensive. Ignoring it can be very expensive. Pre-purchase inspection is critical.

Have it painted and kept indoors can solve a lot of the challenges...

Best regards,

-a-

[Saltaire]

Minor flaky corrosion on the surfaces of any aluminum airplane is common. On a Mooney my biggest concern would be the 4130 steel fuselage frame. It is difficult to see if the frame has corrosion without taking some parts of the airplane apart in order to get a good look (interior and exterior components).

On the aluminum, you can remove many of the wing and fuselage panels in order to take a look inside. Look for the same corrosion you saw on the control surfaces on the inside surface of the inspection panels. It will give you a good idea of what the aluminum looks like on the inside of the airplane.

On the frame keep in mind that until the early 80’s, Mooney dip primed the frame in zinc chromate which literally sits on top of the metal not really bonded to it. They changed over to an epoxy primer in the early 80’s which offered much better protection over the zinc chromate primer.

Joe

[N601RX]

Have it opened up by someone who knows where to look. If its just a few small external spots it would not be that big of a deal to me, but if it was internal or coming out from around seams you are asking for trouble. Check the wheel wells closely, look for bubbling paint. Of the 5 planes I looked at 4 of them had corrosion in this area.

[FloridaMan]

Even a well-maintained airplane, if it's subject to SB208B and it has not been complied with, can have extensive corrosion of the tubular frame. My airplane, a southwest airplane with no corrosion found in the MSC's inspection, has a 337 on file from nearly 30 years ago for tubular members being replaced near the pilot's left knee. Supposedly you want somebody to scope the insides of the tubular structure.