Not even 80k and holy rust! This was rust free 5 years ago. LOVE THE MIDWEST

[3800series2]

Our 2003 LeSabre that I was checking in on today. Wow. Removed the rocker covers. The driver side rear dog leg is SHOT. The hole is about big enough to fit hand in. The under body is still relatively clean. Got all the loose rust off, then hit it with rusty metal primer followed by undercoating. I plan the fill it likely with foam of some sort just to block it from filling with road debris. Hopefully that will extend the life a few years.

added a photo of the inside of the front right fender after removing that soft splash guard material. Does anyone know if that is needed? Seems as though it just harbors moisture.

anyway, thought some might be able to relate and find this interesting.

 

[2007LucerneCXL]

Depending on how involved, there will be a other suggestions, will be the level of repair or replacement. It's not clear if what you used was a rust converter but that would be one of the first steps after removing any of the flaking rust.

Filling any possible holes with something may be creating another problem later on and in another spot. Understanding that cutting out the bad metal and replacing is not always a option, cost or vehicle worth, once the area is prepared with converter then fiberglass might be considered. It won't add any true structural support but can fill in a surface while leaving open areas for draining. Rust primer and undercoating are also good, but the surface needs to be preped otherwise it's just covering up the problem to show up later.



Here's a few diagrams on the vehicle so you can see the areas and connection points.