Rust under rear window - not only the corners

[kclem19]

See pictures. I removed the window and removed the rust as best I could with wire wheels/scotch brite wheels on the end of a drill. I also used a dremel tool with a sanding wheel to get to some sports. I tried using a sanding wheel on an angle grinder but didn't have much luck. I think this sanding wheel was 120-160 grit which was the problem.











Overall, the piece feels pretty solid. Here are what I think my options are:

1. Media blast, epoxy primer, bondo (Pro: I can do it. Cons: Wont fully remove rust?)
2. Media blast, lead filler, epoxy primer (Pro: I can do it. Cons: May damage paint/coating behind the panel to create more potential for rust, Wont fully remove rust?)
3. Tig weld holes and fill with lead/primer or primer/bondo (Pro: I can do it. Cons: Will damage paint/coating behind the panel to create more potential for rust, Wont fully remove rust?)
4. Either fabricate patch panel or get one cut from another car and replace the entire piece. (Pro: Will fully remove rust Cons: I can't do this myself, Potential to damage paint/coating behind the panel to create more potential for rust depending how it is done)

Is there anything i'm missing? Any thoughts here? Any suggestions from people more experienced than me?

[962porsche]

if it was in my shop we would just cut the hole area out bend up a new piece and weld it in .
taking some sheet metal bending it on the metal brake then using the shrinker /stretcher get the needed shape if the piece .
after cutting out the bad if there is any rusted spots in the area under the patch piece they would get spot blasted then treated with zinc primer .
we then would do the final fitting of the patch piece and weld it in place .

we also have a junk shell out side so we would check to see if that area on the old junk shell was any good and maybe use the piece from that ??

[keith28]

If you have not already done so you should remove all of the sound deadening insulation inside and make sure the scope of the repair does not extend to the parcel shelf and beyond to the rear seat pans.That insulation can hold moisture for a long time.The area where the rear seat back panel rises up and overlaps the parcel shelf contains foam which also helps it to rust(possibly not all year models)but may not be visible from the exterior side.

[lrodri64]

Hi,
I was working today on the same condition.

[erio]

Originally Posted by kclem19

See pictures. I removed the window and removed the rust as best I could with wire wheels/scotch brite wheels on the end of a drill. I also used a dremel tool with a sanding wheel to get to some sports. I tried using a sanding wheel on an angle grinder but didn't have much luck. I think this sanding wheel was 120-160 grit which was the problem.



Is there anything i'm missing? Any thoughts here? Any suggestions from people more experienced than me?

2 options. Replace rusted piece or, cover with tin. First with good tin paste untill it shines, and than tin with led. will cover and dip into all holes,

[Matthew Barnes]

That's pretty good rust. Could be the tip of the parcel shelf iceberg.

Check the corners of the parcel shelf above the engine lid hinges. (red circle)
A good way to get a good picture is to look from inside the engine bay.

Also, as the wise men say, the sound deadening holds moisture and that seal was clearly knackered. There is a seam in the taigas that runs approx where the dotted line is. This acts as a perfect rust trap.

Good idea to get a complete picture of the rot before you decide which route to take.

[Cook&Dunning]

I agree with earlier posters - you need to pull the sound deadening away all the way down to the kick plates below rear seats. It looks like more than just the cowl needs to be replaced. Ask me how I know.