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Posted by: bkrantz Apr 26 2020, 07:54 PM

As shown on my build thread, I am working on the rear of the body, including the trunk lid. This is a donor lid I got last year to replace the rusty original.

Now with the work I was doing to straighten the new lid edge, I found rust where I thought was clean--should have known better.


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Posted by: bkrantz Apr 26 2020, 07:57 PM

Some quick surgical exploration makes it look like the rust-through of the inner brace is confined to a small area. But heavy surface rust is sure to be present all across the brace, and the inner side of the skin.

Any collective wisdom on what to do? Explore more and patch the local rust? Try to chip away the rest of the interior foam? Use a rust treatment? Or cut out the entire brace? Or don't bother and go looking for a better lid?


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Posted by: djway Apr 26 2020, 08:21 PM

I completely removed the skin on one hood I did. I blasted everything then repaired what was necessary the put the skin back on. Saved time in the long run.

Posted by: rjames Apr 26 2020, 11:00 PM

Is the inner layer only attached around the perimeter?

Posted by: cn2800 Apr 27 2020, 07:23 AM

How did you remove the skin from the frame? The frame appears to be captured by the rolled edge of the decklid skin. Did you cut around the edges, or did you actually un-crimp the edges? I’m wondering because I’ve got a lightly bent hood that could be fixed if the two parts were separated.

Posted by: dr914@autoatlanta.com Apr 27 2020, 08:26 AM

as long is the top is not perforated, you can fix is like in the picture, The insulation sound deadening packing and leaking rear tail lights and heat is what rusts the lids. THANKFULLY we bought Al's inventory of perfect used rust free california deck lids so we now have plenty of GOOD ones (along with the over 500 NOT GOOD ones!

Posted by: djway Apr 27 2020, 10:33 AM

I opened up the edges. Google “replacing door skins” which is done all the time.

Posted by: bbrock Apr 27 2020, 05:26 PM

My frunk lid had spots that looked a lot like that and I was able to patch them. I also made up a wand attached to a pressure bottle sprayer that I ran through the channels to treat the guts with ospho.

Posted by: bkrantz Apr 27 2020, 09:38 PM

Thanks, everyone. More questions:

1. If I try to repair without undoing the edge crimp and taking off the skin, how worthy is this? How likely that rust in the crimp will win out?

2. If I go ahead as started, and cut out sections of the inner rib, I can get most of the foam out. Then what? What rust treatment?

3. Should I just spend the time and money to get a better lid?

Posted by: bbrock Apr 27 2020, 10:31 PM

Can't speak to getting the foam out but I think phosphoric acid (e.g. Ospho) does a very good job treat the rust and can seep into crimps and crevices nicely. After rinsing the Ospho with water and drying it with a heat gun, I followed with Eastwood Internal Frame Coating add protection. After all that, I looked inside with a boroscope and liked what I saw. After I painted, I followed up treating all the cavities with 3M Cavity Wax Plus. I might have gone overboard but really like cavity wax and figured I'd provide as much protection as possible. Car hasn't been on the road yet though so can't say how long it will last.

Posted by: mepstein Apr 28 2020, 08:13 AM

Some guys like BBrock are awesome DIY'ers. I'm a WTB'er in the classifieds.

Posted by: bbrock Apr 28 2020, 08:42 AM

Ha! For the record, I WTBd my rear trunk lid but it was farther gone than this one. All but about 50 square inches of my original trunk lid skin ended up back in the car as patches and fabricated parts though, so she's still with us.

Posted by: StarBear Apr 28 2020, 08:49 AM

But greatly admire those with the area, tools and expertise to DIY.

Posted by: aggiezig May 1 2020, 12:21 AM

I encountered this same crap on my trunk lid. I ended up dissecting, removing as much foam as possible, using phosphoric acid, and finally coating with master series before welding back up. The clean metal got a coat of epoxy primer and then seam sealer before paint. I'm pretty confident in the repair, it should hold up another 45 years.

Link to my thread with pics: http://www.914world.com/bbs2/index.php?s=&showtopic=289586&view=findpost&p=2593726