Take a look at this rear section. I am thinking because the bumper covers 90%, you can barely see this area with the bumper on) clean it up, hit it with some rust encapsulator and find a rubber/vinyal type flexable moulding that will stick on and cover up the length of the area? Only need someting about an inch wide. I was looking at black door edge guard material-would work but not wide enough.IMG_0267.jpgIMG_0266.jpg

 

I would try and fix it the right way. Rust like that will probably need cut out to stop it completely. Your idea is not a bad one but I would be worrying about it rusting worse. Do you have a MIG welder? I bought a cheaper Lincoln MIG and taught myself to weld , remembering high school metal shop. It was $450 I think but would work on what you are trying to fix.

 

I forgot to mention that I was going to use a cut-off whell and remove most of the rot. Instead of having a new piece of metal cut rolled etc and welded in place i was thinking about some type of molding. Yes I have a new Millermatic 180 MIG. Thanks.

 

I love the car and it looks like you are doing it right. If you remove all the rot first I think your idea will work fine.

 

If you can cut out the rot and weld in new metal then do that. I repaired rust around the rear window with a wire wheel, rust converter, and rust encapsulator because I don't know how to weld. It worked ok but if I welded in new metal it would definitely last longer.