Rust- Once It Starts...

[coldwar]

Holy crap! I just felt my driver seat give way the other day- kind of turned into a rocking chair. So over the weekend I got a chance to investigate. I found the support bracket that is welded to the floor and inner rocker panel had broken off due to rust. So when I lifed the carpet panels, I found the entire seam where the floor is welded to the rocker panel and front bulkhead is rotted away. At the left front corner there is a huge gaping hole and the carpet and sound damping was sopping wet and rotting. Further investigation revealed a hole where the wheel well is welded to the outer rocker panel- at the jack point of course. I've checked the passenger side and the rear floor- all OK thank goodness!

So far, I've cut, bent and laid in some new body metal from inside, with a bit of Bondo where needed, but I'm not sure of the best way to really finish the job right. I could get it all welded up of course, but I'm of the opinion that welds are often the first place where rust will attach again. Another option would be to screw the new metal panels down with sheet metal screws sealed up with silicon, and apply some POR-15 paint and putty along the rusted seam from outside- underneath. With this approach, the only thing I'd bother welding would be the jack point and a new metal bracket for the seat. Keeping in mind this will never be a show car, what would you guys recommend?

Dave

1976 W115 300D "Pearl"

[rs899]

IF you don't want to weld you might want to look into using a purpose-made 2 part epoxy metal bond that is sold by the auto body trade. I have used it to repair the area you are talking about in my W123 240 D and it has held up well for 2 years. You can still use screws or rivets if you wish but the epoxy is said to be as strong as a weld. I am eventually going to use it to glue on the bottom half of a rear quarter panel