This roof section replacement is pretty rare. Having said that, it's worth talking about since the principles applied here would be common across all roof, hood and trunk section replacements. This is a Florida car and I've noticed, over the years, that southern cars tend to rust in the oddest places.

First of all, this car was purchased long distance over Ebay. In the pictures, the rust had been covered with body filler and then brush painted to mask as much of the damage as they could. I don't believe that it was a malicious act, I don't think that who ever did the repair really had a notion of what was required to do it correctly.

Given that as a basis for the scenario, once I picked out the body filler, this is what we found. The sheet metal was rusted through and had been leaking water into the roof support for some time. Left and below are a couple of views that need no explanation.
The first order of business was to discover how bad the structural damage was (above, below and right). Using a plasma cutter, I removed a section of the roof skin over what I suspected would be the damaged area. It was extensive and at this point there was only one option, and that was to replace the damaged section with a good piece from another car. Since the damage was in such an unusual place, we were able to get a replacement piece from a local junk yard and didn't have to go out of state.
 
The next order of business is to remove the damaged sub frame section.

Once removed clean up was required to get rid of any remaining surface rust and section out the replacement piece from the roof section of the donor car.

  
The roof section has been ground and cleaned up. A reinforcement will be added to help minimize the distortion from welding in the replacement section.
The donor piece has been fit to the car and is ready for clean up and welding. Coincidentally, the donor car was red as well. It didn't provide any real benefit by being the same color but it's worth noting.
Welding is complete and it's time for the body filler. The repair came out with a minimum of distortion and other than the fact that roofs, hoods and deck lids are a pain to finish, finishing the repair shouldn't be that difficult. As with all low tension repairs, light sanding and a lot of it.
The body work is complete and the preparation is underway for paint. I should have used the step stool in the foreground to get a better angle on the roof when I took this picture. Filling, priming and block sanding now complete, we're ready to do the finish prep for the base coat, clear coat process.
Color and clear have been applied. Assembly and clean up are next. Then......drive it.

Author: Joe Quaranto