Well, at least it's a Ford. My daughter-in-law's Explorer has a rust problem on its roof. The roof has pressed-in grooves for stiffness and the grooves hold moisture. Living in Portland, OR, then do get plenty of moisture.
My question is: Can anybody recommend a really good rust inhibitor for this problem ? Is POR-15 really as good as it claims, for instance ? This roof has already been repainted once, but the rust came right back. I'm guessing that most body shops go for cosmetics and don't know much about long term rust prevention.
The general plan would be for my son to do the rust removal and surface prep this time, then probably take the car to a shop for overall repaint of the entire roof.
Strip the roof to bare CLEAN metal,remove all traces of rust, prime with epoxy primer, apply sanding primer over that, apply color over that. It will not rust if done this way with quality paint.
POR 15 is as good as they claim. If it was my car I would strip the roof to as clean of meatal as you can do without sandblasting and end up with aprox a 180 grit scuff. . Then coat with POR 15. Use their thinner if spraying or any pre wipe down. Then scuff the POR-15 very well and top coat with a good 2 part primer like DP-90 or other. Then put on the finish color paint. Some may agree or disagree on the POR 15, but we have had very good luck with it.
POR15 looks like crap if left out in the elements for a while, it turns to a nasty looking powdery look, YES it needs to be top coated, but sanding POR15 ????
Get some RHINO coat in the approximate color and roll it on with a small roller for texture. Usual under-prep is needed tho.
Just poor prep if it came back that fast.