Rust in door jam

[rs74]

 I have a bad rust issue in the door jams and am not sure what is causing it.  The rust is coming from underneath the paint.  It is more noticable on the drivers side but the passenger side has it too. Could it be from the drip rails somehow. The truck has pretty good paint on it. I should add that the truck is an 85 model silverado. I am going to try to upload some photos.

[rs74]

Here are a few other photos

[beastie_3]

If its been repainted with body work, it looks that area wasnt paid too much attention. I really dont see water collecting from the drip rails, it would have to be clogged somewhere downstream. I just put drip rails on after about 7 or 8 years. Holes were exposed and it would take an awful a lot of rain and washing to fill that area up.

[jaredts]

I have the same rust.  There should be seam sealer in that seam, but it doesn't do much to keep out moisture.  Like pointed out before the screw holes for the drip rails let a little in--thats all it takes.  Any moisture let in can't get out and very humid air and maybe even small pools of water will be trapped.  Bad thing is, you can really only treat what's visible and seal it back up--knowing that there is more rust between the two panels.  Be meticulous about getting all of it out of the pits and it should last a little while.  You and I will both be tackling that area again a couple of years down the road.

[greeneon_01]

I can see by the hard line in the door jamb that it has been repainted on the outside but not the jambs. Like jaredts said...it doesnt take much moisture to cause rust. My guess is that when it was repainted that seam sealer either wasnt put on or missed in a few spots and started the rust. Make sure if there are any holes that you remove that area when you fix it....or it will come back. You probably wont get all the pits out..but make sure to get all the surface rust out of the pits. And make sure to use a metal conditioner or rust preventative to make sure it doesnt come back. And of course..make sure there is plenty of seam sealer on the drip rail. Thats my $.02.