More paint bubbling questions.

[darmahsd]

After researching this forum, I see different opinions on this
subject. I'd like to bring it all together here.
It's hard to find a 2nd gen like mine, especially in the snow belt,
that doesn't have any paint bubbling around the license plate
enclosure on the aluminum tailgate. Also happens on the aluminum
hood (on both my old '97 and current '05).
It has been explained to me that the cause is by dissimilar metals
causing electrolysis. This is especially true on the tailgate where
Ford used fasteners to attach the license plate enclosure frame
that weren't properly isolated and would react with the aluminum.
When I repair mine, I will better isolate or even change the type
of fasteners. What I'm not sure about is the paint prep. Another
thread recommended self etching primer before paint. Other
advice was to use a two part catalyst primer. Which is better
to use? Or, would it be best to use both, before topcoat?
If both are used, I would think the etching primer would be applied
first, then catalyst primer and topcoat. What is the opinion of
the autobody experts as to the best way to prevent this from
happening again?
Stephen

 

[BIG GREEN FORD]

I repaired my hood. All I did was sand it and put the top coat on without primer. It's been perfect for 2 years (but I live in Florida)
My painter guy said that happens where the clear coat is weakest and it penetrates the paint from underneath causing it to bobble.