Rust on metal roof from panel frame and dripping rain

[keepsake]

Maybe someone that reads this can chip in.

I put solar panels on metal roof 11 years ago. Where the panel frame drips onto the sloped roof it is rusting like crazy. No rust anywhere but along that drip zone. What is anyone doing about this ? I am told this is Galvalume 5V roofing. The rest of the panel area is unaffected by rainfall.

 

[rhino]

Is it possible you live in an area that has abnormal amount of air pollution or acid rain (especially if near coal power plant)? That could cause rain to slowly leach aluminum from the frame and have galvanic interaction with the steel.

 

[keepsake]

Live in mid-Florida, Zip 33523. If salesman had only told me to paint with protective elastomeric, maybe wouldn't have even occured.

 

[timselectric]

I'd guess that the toxic rain itself, is the problem.
And the solar panels are protecting the rest of the roof from it.