Emergency skin corrosion info please!

[yochanan]

I've read tons on the forum about skin corrosion but need some emergency advice on how to save my 72 Tradewind.
A previous owner had replaced the "Tradewind" side, trim plates with two that had been molded by another source other than Airstream.

The metal used in the trim plates caused an extreme bi-metallic corrosion issue underneath the plates until they actually fell off the trailer when the rivets actually corroded through. Underneath the
trim plates, there had developed SEVERE intergranular, skin corrosion.

As the trailer is in a coastal evironment as well,....what can I spray or apply to these two areas to keep them from completely rotting through??
Now that the trim pieces are no no longer attached, will a coating of LPS-3 or something provide ANY emergency solution to stopping the corrosion in those spots.....??
HELP....

[Aerowood]

There is only one way to truly stop intergranular corrosion and that is to remove the cancer per say. LPS3 is indeed a good water displacement agent but it would be to little to late. Your only permanent fix is to cut it out and scab on an external repair, or if you are real handy with metal work, the installation of an internal doubler with a flush filler installed with flush rivets, or replace the entire skin. Sorry

Kip

[Kevin245]

It sounds like galvanic corrosion (reaction). This is an undesirable side effect that can occur when metals of differing nobility are in contact with each other. The metal of lower nobility will experience galvanic corrosion. Basically becoming a sacrificial anode of sorts. The desired AI Index in a harsh condition such as a coastal area should be less than 0.15V where possible.

If the damage is severe then Kip's suggestions are probably your only options.

Kevin