I'm sure many of you have the dreaded "door seam rust". I'm considering doing this. Grinding down the rust as much as possible, maybe add some naval jelly (not sure if this will interact with next step) primering, and then masking off some straight lines at the seems and spraying it with that aerosal truck bed liner. I read on the label that it is somewhat rubber like, so I wonder if this would help prevent future rust????
I'm at my wits end on this seem rust, I can't see how a 5 year old truck can start to rot like that.

 

I too, am going to do this with my tail gate. Below the crease on the bottom some paint is peeling off. However, if you don't get ALL the rust off, it'll just come through your hard work.

 

here is door #1 before and after...not sure if I like it or not, but its gotta help some

 

nothing wrong with that--whos going to see it--and if they dont like it--tell them not to look!!!!!!!!!!!!!!!

 

I would not spray the bottom of the door with bedliner, reason is the moisture is getting to that seam from inside the door. The bedliner will hold the moisture in and you will rust behind the bed liner. I would pull the inner door panels, clean up the inside of the door the best I could and spray one of the rust attackiing frame paints in the door bottom.

 

From what I can tell that will happen no matter what is applied. The wheep holes they put on these doors are too high. There is about 1/2" inch of space from the wheep hole to the seem...which means water will not effectively drain from inside the door properly. The only REAL solution would be to add wheep holes lower on the door, to let water out