Safety Structure Attacked by Rust

[jka1]

About 2 years ago my '97 V40 started to show signs of corrosion in the lower area of front fenders. This summer I decided to take care of it and that's what I discovered.

The hollow space between fender body panel and car's structure was full of mud and dirt for many years, being constantly wet and caused the 'structure's shell' to rust out, so the mix of rust and mud was in direct contact with the safety structure for quite a time.

What do you think about it? The car is in top condition apart from that. But I'm worried it's time to say goodbye if the safety is compromised. It's just that I feel it would be such a waste of a very good car.

So, actually, the question is: Is the safety in an event of a frontal impact significantly compromised because of the corrosion?

It's hard for me to evaluate how deep the rust has penetrated and I don't know how thick those steel profiles originally were and what's the margin for them to be rusted and still preserve the required rigidity.

I attach the photographs.

Any of your comments or opinions would be very valuable for me.











Full resolution images:
http://i.imgur.com/Yi7u7PI.jpg
http://i.imgur.com/XheGoeK.jpg
http://i.imgur.com/pvUELI9.jpg
http://i.imgur.com/8VtlWVg.jpg
http://i.imgur.com/5iKaTho.jpg

[druid]

That's nasty looking, if it was mine (after i stop crying) I would use a rust treament on the inner and put a new sill section in, IF you want to save it

[Phandy]

I would not worry too much; I have a 1988 Bedford Midi Van and that has a rust problem.

Hit the rusted areas hard with a hammer and see if any more holes develop. Buy some 80 % phosphoric acid off ebay and treat the rusted areas. Once dry cover with anti-rust primer (Hammerite), then fibre glass the hole and paint over it.

I personally would not worry at all from a structural safety perspective if that was my car.

[jka1]

@druid
Yes, I want to save it, I like the car a LOT. The new sill section (I understand that the outer one) seems to be a must.

@Phandy
I've hit the rusted structural areas with a hammer and also with a spike and gently with a hammer, so I've removed all the loose rust. I have sanded the surface a bit too, probably should more, but I really hate the dust it creates.

Yes, I plan to treat the remaining rust with some rust eater like 80% phosphoric acid then apply anti-rust epoxy primer, to neutralise the remaining rust and the apply 2-3 layers of hammerite or other resin-based coating.

I've carefully examined the rusted area and I attach you a photo, where I've marked the actual damage caused by rust. Green area is just a surface rust or simply rust that is on top of a coating (it comes from rusting out of outer elements). Within the red line you can see actual damage: about 1mm deep recessed area.

[canis]

Hmm. The fibre-glass option - you might get away with it if you make it look good enough. But when I was taught to do these repairs, I was warned strictly not to 'pug' sills, and one MOT inspector very sternly warned me he was gonna lift the carpets to make certain of it!

The correct repair would be to cut off the outer sill entirely. Chop out the rot on the inner sill. Weld in a new plate, and then weld on a new outer sill.

It was a very common repair in the old days. Cortinas were terrible for inner sill rust.