A flaw in the way that the aluminum is anodized causes oxidation under the paint even with the absence of air and water.
Rust on jeep door hinges.
Factory door hinges certainly degrade over time which is why many spring for stainless steel versions either in silver or black to get that showroom fresh look.
If it s a new to you jeep then those hinges are mostly like rusted up and the doors are going to be a huge pain in the rear to remove.
The moisture mixes with oxygen and forms rust.
You may spray some anti rust or pb blast on it and clean the area with a copper wire brush so they will still slide when you want the doors off.
I had a similar issue w my 2007 jeep hinges.
As far as the hinges go the only thing i would worry about is getting the doors off and on.
If you own a jeep jk built in 2007 or later be on the lookout for bubbling paint on the outside hinge of your door.
Whether it is hinges that have faded or rusted or just a new look you want on your vehicle swapping out door hinges can refresh the way you and others look at the jeep.
Use liquid wrench penetrating oil on the hinges.
Called the 877 noted above.
My rust corrosion warranty expired 3 months ago but the customer service person put in a request for the hinges to be repaired under warranty.
In addition to its unsightly appearance rust can corrode and weaken the structure of metal causing holes to appear and increasing the possibility of the hinge breaking or snapping when the door opens.
However if you have rust on your door hinges you likely have rust elsewhere.
He had to elevate that for approval and i will receive an answer by tomorrow as to whether the repair will be approved.
Looking through the jeep i noticed a lot of rust which seems premature.
The top of the hinge is already rusted pretty good.
Rust accumulates on door hinges when moisture is allowed to build up on the surface of the metal.
As is pretty common i also have the rust issues on the inner door hinges but i was a bit shocked when i saw this.
The first picture is of a bracket right behind the engine cover.