Most of our filiform appeared within the first 3 seasons.
Not all rivets and cut edges will be effected.
I have cleaned and sealed the entire trailer at every Spring get-ready.
Thankfully new outbreaks have been restricted mostly to chips in the clear.
A close inspection during the frequent washing's will reveal any new outbreaks.
It's important to find them before
they spread. Cleaning all the corrosion from the panel and sealing with clearcoat has worked well for me.
Currently using KBS Diamond Clear.
"Sticks & stones can break your bones...and hail will dent your Airstream"
So when is this..."old enough to know better" supposed to kick in?