Rear trunk lid rust, How to repair rust for paint Options

[artluvr]

My 1974 914 has the typical bubbling paint on the rear trunk lid due to rust caused by the foam insulation. I have cut out a section on the left side of the lid and removed the foam to treat the rust. Should I replace the foam with something else to give rigidity to the lid? Also, should I go ahead and do the same thing to the right side of the lid, even though there are currently no pin holes there?

I am stripping the car for paint--my first experience. Thank you for any suggestions or experiences.

[boxsterfan]

At that point in a restore, I would do whatever it took to get all the foam out. Did you get the foam out from under the sail panels area and the rear wheel arches (in rear I think)?

Someone else here will have good ideas on what to do with the rigidity.

[amfab]

A while back, I repaired the back edge of my trunk lid. The frame was rusted underneath and had a small crack in it right around where the latch was and this caused the latch area to flex enough so the trunk would not sit down all the way against the weather stripping. Someone on this site recommended 3M Panel adhesive and it worked amazingly. I do not know how it would work on the whole frame because I am not certain where it is bonded, but you should definitely look into it.

Here are a couple of videos about it:


https://www.youtube.com/watch?v=X7pWRqAZIJM

https://www.youtube.com/watch?v=oxHActyy9Ds


It is about 45 bucks and the special gun is about 65

-Andrew

[Costa05]

I have been using Klean Strip Prep and Etch from Home Depot. Sold by the gallon for about $12. It is basically a rust converter that is similar to Rust Mort Converter by SEM. I do multiple applications with paint brush and scuff between coats until rust appears to be gone. Remember to neutralize following applications. Good reviews and happy so far with the results. Epoxy primer follows as a sealer to bare metal and paint prep.

[artluvr]

At that point in a restore, I would do whatever it took to get all the foam out. Did you get the foam out from under the sail panels area and the rear wheel arches (in rear I think)?

Someone else here will have good ideas on what to do with the rigidity.

Thank you for your response. I was unaware of the foam in the sail panels. No visible pin holes or paint bubbling there. I would have posted photos but haven't figured out how to do that yet.

[artluvr]

A while back, I repaired the back edge of my trunk lid. The frame was rusted underneath and had a small crack in it right around where the latch was and this caused the latch area to flex enough so the trunk would not sit down all the way against the weather stripping. Someone on this site recommended 3M Panel adhesive and it worked amazingly. I do not know how it would work on the whole frame because I am not certain where it is bonded, but you should definitely look into it.

Here are a couple of videos about it:


https://www.youtube.com/watch?v=X7pWRqAZIJM

https://www.youtube.com/watch?v=oxHActyy9Ds


It is about 45 bucks and the special gun is about 65


I was unaware of the body adhesive. I spent all last week welding in a patch to the front trunk floor where an air compressor was probably housed. Glue would have been easier but I learned a lot about welding and bead rolling--doing it two times gave me twice the experience.
-Andrew

[artluvr]

My 1974 914 has the typical bubbling paint on the rear trunk lid due to rust caused by the foam insulation. I have cut out a section on the left side of the lid and removed the foam to treat the rust. Should I replace the foam with something else to give rigidity to the lid? Also, should I go ahead and do the same thing to the right side of the lid, even though there are currently no pin holes there?

I am stripping the car for paint--my first experience. Thank you for any suggestions or experiences.

Your method is more economical than what I got from Eastwood--Rust Encapsulator, Internal Frame Coating and Rust Convertor.