Another Fillaform Question

[glenrms]

Does anybody know if fillaform develops on the inside of the outside skin? I have a pretty bad problem, mostly around my side markers and wonder if the fillaform is growing between the walls where I can't see it. Or does it only grow under the clear coat? Thanks!

[Protagonist]

Originally Posted by glenrms

Does anybody know if fillaform develops on the inside of the outside skin? I have a pretty bad problem, mostly around my side markers and wonder if the fillaform is growing between the walls where I can't see it. Or does it only grow under the clear coat? Thanks!

Filiform corrosion by definition only forms under a coating in the presence of moisture. So yes, it is possible for filiform corrosion to develop on the inside surface of the outside wall panels— if the aluminum is clear-coated on both sides.

[TheCabin]

There are pictures of filiform growing from a panel edge riveted under the adjacent panel shown on the corrosion thread. I will look later for the posting but it is within the past few months. But filiform requires a break in the organic coating on the metal; you need the organic coating.

[xrvr]

It's only cosmetic so it won't fall apart from the inside if that is your concern.

[dkottum]

I think the question is, does the inside panel have any coating? If so there could be filiform corrosion, if not then no filiform. Whether it's likely to be a problem is unlikely.

[TheCabin]

When it comes to our AS's, ignorance is bliss. Any deeper understanding than that may cause unhappiness.

[TheCabin]

Here is a link to filiform that grew out from under a sheet which could occur on the inside if there was a crack in the organic layer.

http://www.airforums.com/forums/f142...ml#post1726310

I too find myself wondering what unpleasant surprises are hidden from sight due to the silly methods and parts AS uses during assembly.