Anyone notice the lower door seams on the 2004? They are not welded. I've never seen this before. Just looks like a small gutter. Seems to me dirt and water will get trapped there and rust out the doors from the bottom up.

I'm thinking of cleaning them and filling them in with clear silicone caulk. Anyone have a better idea?

 

If you seal the lower seam, remember that all doors have "weep holes" that allow accumulated water to drain out. You might just cause more problems sealing the entire seam than if you left if alone. My $.02.

 

Car manufacturers and stamping plants use a hemming press to fasten the layers of sheet metal together instead of welding. This process should make a decent seal. I would not think that adding any additional sealant is necessary.

 

The problem is there are no weep holes or "seams". Well, actually there are weep holes but they are above the area I'm referring to and are there to drain water from inside the doors.

There is about a 1/16 gap at the very bottom of the doors between the inside of the door and where the outer skin is bent under to the inside. Normally this is welded. It is already accumulating dirt. I pointed it out to the dealer and they were surprised too. We checked the other trucks on the lot and they were all like that. Thought maybe it was missed on my truck.

I don't see how dirt and moisture will not cause the bottom of these doors to rot.

 

From what a fellow 04 F-150 owner and I can conclude from your question is that the lower LIP on the door skin is actually a run-off channel to allow the water from the weep holes to flow to the rear of the door and out into the slip stream around the rocker panels. A small brush run along the LIP should remove any built up sand, dirt or rocks that may have acumulated in the LIP. I drive my truck down some pretty nast dirt roads here in Georgia and I haven't notice any build up yet, but I will watch for any.