Is this surface corrosion?

[skeptic]

The attached pic was taken inside an M20 aft fuselage.  Does the light colored area on the aft upper skins look like surface corrosion?  It was not evident with the flashlight, but the camera flash is of course much brighter.

 

[thinwing]

hard to tell from photo...for sure the green znic chromate is flaking off and due to rivets being uncoated prob applied at factory...are those white areas white powdery looking???

[skeptic]

Not sure....looks kind of "powdery" in the picture.

 

I also just noticed that part of the lower aft bulhead is blue, and opposed to the green primer color.  I wonder how that happened?

[KSMooniac]

Hard to tell from the photo... you might have to crawl in there and inspect it carefully.  If it is, a Corrosion X treatment or similar should be done quickly!

[skeptic]

Not sure, but I think that light surface corrosion can be treated with ACF-50 or similar chemical applications.

[OR75]

there are two side pannels that are very easy to remove and put back on both sides. (it looks like you have strobe power on one of the side pannel).  

 

About 8 or 10 machine screws on each pannel and you can see if it is white powder (aluminum oxide) or just dirt. 

 

It is amazing how much dirt a Mooney tail can scoop.   If you don't clean it once in a while , you could start growing a plant in there at some point !! 

[OR75]

 

I also just noticed that part of the lower aft bulhead is blue, and opposed to the green primer color.  I wonder how that happened?

 

 

The blue could be just paint that "leaked" when they painted the outside. Does the exterior has some blue ? 

[NotarPilot]

It doesn't look like corrosion to me.

[skeptic]

The aircraft is blue on the outside.  That probably does explain the blue "patch" inside.

[Alan Fox]

There is a light dusting , Not too many 50 year old birds with a little dust on them....  Nothing to worry about ,

[AmigOne]

I would agree about not to worry, the front bulkhead looks just like the zinc chromate is flaking, further back is hard to tell but if I were to guess I'd say not to worry. Clean it if you can and apply some anti-corrosion stuff which is always good, specially if you leave near the sea.

[bradp]

Agree that nothing looks obviously corroded from the picture.  However, the small trail of something on the bottom of the lowest part of the floor may indicate something had collected down there.  If I'm not mistaken, there should be a drain at the lowest point of the empennage; check that it's not blocked up.  May be a good idea to clean the areas and either re-spray some zinc chromate / phosphate or use a dielectric anti-corrosion compound.

 

Not to take the thread too far off topic, but anyone found that corrosion X attracts dirt and tends to pull old zinc chromate off the aluminum?

 

Brad

[Dale Logsdon]

that is corrosion. Hows the rest of your airframe? You need a complete airframe inspection and treatment before it gets any worse. There are worse spots that you haven't seen yet.

[skeptic]

that is corrosion. Hows the rest of your airframe? You need a complete airframe inspection and treatment before it gets any worse. There are worse spots that you haven't seen yet.

 

 If this is corrosion, can it be treated at this early stage with something like ACF-50 or similar?

[Marauder]

Before you jump off a bridge, have someone familiar with filiform and intergranular corrosion look at it. The picture is not a close-up and what you may have is nothing more than paint failing. The good news about Mooneys is all that green stuff is something you don't find on all airplanes and the zinc chromate paint helps ward off corrosion. I do agree you should have your airframe looked over if they do find corrosion and yes, it can be treated if caught early enough.

[OR75]

only one way to tell: open a side panel by removing a few screws, clean with a rug and stoddard solvent and look.

[N201MKTurbo]

It looks like someone used a power washer to clean the tailcone and stripped the paint. Get some more chromate (good luck) and touch it up.

[RJBrown]

I believe this is surface corrosion. This picture was shot during a pre buy on a TLS I chose to not buy. Shot from below looking at the inside of top wing skin.

[fantom]

I believe this is surface corrosion.

 

Quite mild, but that's it.

[skeptic]

Thanks for posting this picture.....very helpful.

[carusoam]

RJ,

Was that the only spot? Or did it spread far and wide?

-a-

[RJBrown]

I did not buy the plane. Someone on this forum now owns it. All I know about the corrosion is that picture. The plane was stored outside in coastal California.