The main reason why I have my cabs and body parts media blasted is for those places which you mention. Once you blast those seams where the sheet metal joins or overlaps, there will be no rust or paint left on the outside. I then use SPI epoxy primer. This product will seal those areas, preventing the rust from creeping out later.
One important note. Do not treat these areas with rust preventers like Ospho if you are going to use epoxy primer.. Epoxy primer does not get along well with acid rust converter products.


1952 5-window - return to "as built" condition | 1950 3100 with a 235 and a T-5 transmission