2017 Ford Explorer - Paint Bubbling

rusting and paint bubbling under and on hood edges

Still under warranty. See your dealer.

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My  guess its an aluminum hood. none of them seem to be able to consistently keep paint on these aluminum hoods . Had the hood to our 14 Grand Caravan replaced due to bubbling on the aluminum hood . Luckily FCA did free of charge even though the car had 60000 miles on it .

I have owned 2 Mustangs with aluminum hoods. My 07 was sold in '16 with no bubbles. My '13 is now 6 (and 70K miles) and it has no bubbles either. Both were touched up with paint whenever I saw a chip. Maybe that is the difference.

How the hell does aluminum rust?



Al + O2 = Al2O3

True, but that won’t cause visible rust or bubbles, George.

From the link below …

Filliform corrosion loves to screw up your paint job but generally isn’t a structural issue, according to the association. It appears on the substrate underneath your coatings, often after a” stone chip, scratch or sharp cut edges, or punched or drilled holes” create an opening. It can spread underneath the coating, capitalizing on voids in an adhesive or an inconsistent oxide layer on the substrate, the trade group suggested in an October 2017 study of a bubbling hood paint job.

“Filiform corrosion typically results in paint bubbling and separating from the metallic surface,” the Aluminum Association wrote. “This form of corrosion appears as thin thread-like filaments filled with corrosion products (white powder) beneath the coating.”

This is why an OEM or paint manufacturer might have strict guidelines for how you prepare a surface before refinishing it. The trade group recommends you follow OEM instructions and do a nice job of cleaning the metal and removing defects.

“Another very important corrosion on aluminum that occurs naturally is Aluminum oxide,” he wrote. “Bare aluminum exposed to moisture and oxygen forms a hard protective coating (Al2O3). This compound will cause porosity in your welds, and paint, adhesives and body filler do not like to stick to it. It needs to be removed prior to working on aluminum.”

From what I’m reading Ford seems to believe the problem is the aluminum panels are impure, & contain some iron particles, and it’s the iron that’s corroding. Seems very possible. I recall there was a problem in the 1970’s with copper plumbing pipe contaminated with iron particles, and over time the pipes already installed in houses would start springing pinhole leaks, and causing all sorts of expensive to repair problems.