How I fixed door hinge cracking
In my case the inside hinge plate was separated from the skin enough to leave a gap between the two surfaces.
I took off the inside door panel so I could have a look inside to make sure I would not drill through something I did not want to drill through. Then I put a jack under the door to support it while I loosened up the bolts holding the door to the hinges. This is so I could open the door beyond the normal range to get access to the spot welds with a drill.
Here is a shot of the cracked sheet metal. I let this go too long. I could hear the crinkle-crackle when the door was fully open, but did not inspect it closely when it first started. It looks like the welds furthest away from the hinge failed first, then the extra stress at the hinge mounts caused the cracking at that location.
The upper hinge was not affected, so I only had to deal with the bottom hinge. A new door from Ford was almost $2000, and that does not include painting and swapping the glass and other parts. So a repair attempt was definitely in order.
The next step is to drill out the welds and a few extra holes between, above and below the welds. I might have gone a little overboard here. By having the holes all in a line, there is a new path for a crack to travel between the holes if there is enough stress to cause more cracking. Look inside the door carefully before you drill, since the inside hinge plate does not extend very far past the factory welds. You don't want to drill through the door skin and not hit the hinge plate inside. I started with a 1/8" drill bit. You will need a long bit, since there is not enough room to get the drill chuck in there with the door still (loosely) attached. If you have time and room in your shop, take the door off and you will be able to do a much better job.
After you get the pilot hole started, drill out to the size of rivets you will be using.
I prepared about 10cc of JB Weld to squirt in between the door skin and the inside door plate. A syringe from the feed store was about $0.50. Pack the epoxy into the syringe and force it in between the panels as much as you can.
Then put some rivets in the holes and you are 90% done. I had these 1/4" rivets left over from another repair on our Lincoln. They are big enough that you cannot use a hand-operated tool to set them. I borrowed an air-powered rivet gun from work, which sucked them right in. This tool is badass! If you don't have this option, use the biggest pop-rivets you can pull with a hand-tool.
Here is what it looked like when it was all done. Note that the rivet heads are not flush with the door skin. This is because I could not get the rivet gun perpendicular to the body panel surface in that tight spot. Since I already had the epoxy in, I just went for it and put all the rivets in, just a little bit crooked. I did not have time to take the door off at that point to get the rivets in straight.
This is a shot of the inside of the door, looking at the expanded side of the rivets. You can see the epoxy has gooshed out of the rivet holes. Hope I got a nice layer between the panels. No way to know for sure.
The next day I tightened up the bolts to re-set the door, and saw that two of the rivets were blocking the door hinge from living in the correct location. So I had to drill out two of the rivets to get the door lined up correctly with the latch and the body opening.
Last thing I did was to run a magnet down inside the bottom of the door to pick up as many chips as possible. Don't want them to start rusting and corroding the inside of the door.
That's how I solved my problem. Time will tell if it was a good repair or not. If the rivets start to get loose, I still have the option to take the door completely off, drill out the rivets and replace them with new ones, making sure that the rivets go in squarely this time.
Best,
CR
