I am trying to tackle some intergranular corrosion on my 78 Cadillac Miller-Meteor Hearse. I need to know if the metal in this area would be considered porous. I have purchased a palm sander and Ospho, I would like to start tackling rust this Sunday.
How big does the afflicted area have to be before we should consider panel replacement as opposed to fiberglass? I have a roughly 4″ corner section leading into my door weld that I know will have to be replated possibly by a fabricator if I can’t learn any tricks. The other sections range from 2″X2″ near my rocker panel to 1/2X 1/2″ appearing in a line of spots along the bottom of my posterior door.