I removed my interior door panels about a year ago and sprayed a 3M product called 'rust fighter-I' down towards the bottom seam. It is for internal panel coating. Part# 051135-08892. It sets to a bee's wax consistency. I made sure the panel was dry before spraying and it did not clog up the drain holes. Also sprayed the same into my the tailgate's internal areas. Don't know if it will help but I believe the old saying that 'an ounce of prevention is worth a pound of cure'...

 

The grease is obviously a good option but, from the stand point of keeping it clean and having to reapply all the time, it's a pain in the butt. The grease would displace or keep any water out of the crease thus removing one of the vital components to corrosion... moisture.

Personally, I've waxed the holy heck out of my creases over the past few months (I make a concious effort to overwax these areas). Thus far, I've noticed that these areas are easier to clean when carwash time comes around twice a week and the corrosion that I've noticed has seemingly stopped.

Don't get me wrong, it's on my list of things to have taken care of under warranty (before it expires) but, in the mean time, I think I'm preventing further corrosion.

RP

 

Wow, it is certainly dishearting to read all the post about Ford rust problems at the doors and tailgate. As an owner of a previous 89' Taurus SHO and 94' Explorer I know first hand that rust always forms at the bottom of the doors and usually anywhere else where outer skins of sheet metal fold inward and then upward on the inside of panels. Only a small amount of panel caulking between the two metals from the factory is all that protects these areas.
I often travel for business around the country looking at other peoples truck for potential rust areas that might pop up and I am aware of the door and tailgate areas of the SuperCrew. Thank God the engine hood is alum. or that would rust too.
For my 02' SuperCrew, I heavily wax these areas with a clear wax and do not wipe off the excess. I also spray the insides of my bumpers with Turtle Spray Wax but should probably get them sprayed with a undercoating. I hate RUST!

 

I just purchased an 03 supercab Fx4. Based on all this talk about lower door rust I took a good look at this area and can see why a problem would develop. I would like to do something about this seam now but am not sure if seam sealer followed by paint is the answer or if I should simply apply spray-on rust proofing to all door seams?