Attention: TDR Forum Junkies 
Living in the rust belt I'm always inspecting out of the way areas on my truck in an effort to stave off corrosion. This morning while my tailgate was down I happened to look at the very bottom of the gate, the pinch joint area on the inside of the gate that you can only see with the gate down. Something looked amiss, swollen almost so I started poking around. Low and behold, a solid 12" of the coating had seperated from the pinch joint and allowed moisture to creep in behind it. Fortunately all but one spot still had the primer coat but once that seal is broken and the sheet metal starts oxidizing things go down hill quick. They used some type of a sealant in an effort to keep any contamination out of the pinch joint as this is an area that always sees moisture and dirt.
Good idea but in my case poor execution. This is at the very bottom inside of the gate and if left untreated would have worked its way around to the outside of the gate very quickly. When you see the bottom of gates rusting away to Swiss cheese this is exactly where it starts.
Picture of sealant used to cover pinch joint. Left piece is the outside, right piece is what made contact to the metal. Notice the brown stain - where the corrosion had started
Good idea but in my case poor execution. This is at the very bottom inside of the gate and if left untreated would have worked its way around to the outside of the gate very quickly. When you see the bottom of gates rusting away to Swiss cheese this is exactly where it starts.
Picture of sealant used to cover pinch joint. Left piece is the outside, right piece is what made contact to the metal. Notice the brown stain - where the corrosion had started
