Much to my surprise rust broke thru this panel on each end where it joins the rear fender. Several years ago I welded in a small patch panel on the left side. The patch was then blended with plastic body filler.
Replacing this panel is a pretty serious job. The gas tank should be removed or somehow made inert to be safe when grinding and welding. Both rear fenders must be removed along with the trunk lid. The panel is spot welded to bracing along it's back edge and brazed to the inner fenders to form a trunk opening.
When I first purchased this car about every two weeks the fuel filter would fill with sand. After many filters this is no longer a problem but there is a lot of very course sand left in the tank. All I can think of is that someone vandalized the car by dumping handfuls of sand into the tank. When the fuel level was low you could hear the gravel moving from side to side. The tank is now drained and baking in the sun to remove all traces of gasoline. Once it is completely dry it will be vacuumed and the exterior given a fresh coat of black paint. Maybe the gravel sloshing around kept away rust but it sure is clean and shiny in there. There was enough gravel removed to fill a large coffee mug.
The tank looked quite good except for some small scratches where light surface rust had developed. The tank had never leaked so a little sanding and a fresh coat of paint should suffice. Fastened to the forward side of the tank were two foam strips that cushioned the back trim panel. I removed the foam to find a serious rust pocket behind the upper strip. Cleaned it up with a 3M rust removal wheel on an electric drill to find the tank deeply pock marked. So deep that there could be a leak. Now I'm debating whether or not to pressure test the tank. Two or three pounds of air and some soapy water and I could be sure there were no leaks. On the other had I could just take a chance and ignore it. I choose the later, hope it doesn't come back to haunt me .
The fuel tank has no shut off and with the fuel line coming out the bottom of the tank, a broken or leaking fuel line could quickly drain the entire tank. As a matter of fact changing the fuel filter requires pinching off the fuel line. Adding a shut off somewhere near the tank way be worth doing.
This photo, looking forward with the trunk at the bottom, shows the rear deck removed. The red brace is just under the front of the trunk edge and was spot welded to the deck. With the deck out of the way the trunk area was cleaned, adhesive removed, and minor rust damage repaired. The tank, now removed, sits just forward of the cross brace. On the left side of the photo, just over the tire, you can see that the top edge of the inner fender is rusted away.
The rear deck was finally welded in place this past weekend (see Restored). It's rear edge was plug welded in place two weeks ago but the forward edge required the fenders in place to be sure of the alignment. On Friday, the car was pushed out into the sunlight in order to work on the door gap alignment. Finally the body is solidly bolted to the frame. The shimming was done and things are looking pretty good. It's been a long time getting to this point. Much of the summer has been spent repairing the rear portion of the body. There were rust holes in the rear valance as well as a small hole in the left side of the trunk. Patch panels have been mig welded in place.
The latest push is to get the interior painted. All carpeting and trim panels have been removed. Peeling them up leaves a heavy residue of glue that is a rubbery form of contact cement. The glue has all been removed using 3M Adhesive Remover and a stiff putty knife. The rear kick panels had sound proofing that was sagging and peeling. It too has been removed, ready for paint. Once all the blemishes have been treated, the entire trunk/ rear body will be primed with a primer/sealer. I have a quart of acrylic enamel to restore it to the original delft blue. At the same time the undersides of all four fenders will get a couple of coats.
My plan has been to repaint the car with a base/coat clearcoat in the original delft blue color. I haven't found a base/coat clearcoat formula as yet. Haven't really spent enough time looking to say it's not available. Next week my store (a NAPA Auto Parts) will start mixing paint so the time is prime to get a little factory rep assistance. If a formula can't be located, a panel can be scanned by a paint anaylizer gun to create a custom formula. I'm hoping to get the painting done before the car is sent to winter storage at the end of October. Unless something major goes wrong, this goal will be accomplished. Still to be decided is the method for painting. Should it be painted as a complete unit or should each panel be painted then assembled? Any thoughts?