Hi,
I have taken off a lot of the sound deadener and found a bit of rust in the passengers footwell over and to the left of the chassis rail. Just wondering what causes this to rust as I'm trying to prevent it happening again.
Cheers!

Finding the same thing in my shell, a bit worse though......... It looks like the wheel arches have been hit with sand, dirt and wet weather and rusted from the outside in. My bulkheads cactus too and inside the water marks and rust spots match up. Yours look pretty good, maybe weld/ patch smother with rust coat and fresh tar underneath? That and I'm not going to drive mine in the wet again
Good luck with it, Drew..........
 

More often than not its water leaking into the footwell from either a leaking windscreen or (more likely) a rusted section of the bulkhead behind the heater assembly (mounted beneath the plenum in the engine bay).

Thanks Drew, same to you mate! I wasn't expecting to find it as there isn't any other rust in the car!
Cheers Paul, I'll have a further look into the heater plenum tomorrow but there appears to be no rust around that area! I was hoping to paint it this weekend but these things happen! 

Rust we can see, can be dealt with a variety of readily available chemical treatments, most are safe, some are
not so safe. Smash Repairers wipe over the bare metal with, (whatever the trade name) a Phosphoric acid and
water solution, this converts the rust that can't be seen, to a phosphate, when dry apply a primer and continue
on with the repair. not a safe way to go for amateur painters/repairers.
Cheers 

might be worth coating the new surfaces with something like POR-15 just incase (or when) the screen leaks again?

The other possibility is leaking through the seam sealer of the joint at the A pillar which is fed by the gap between the front guard and the body.

As you can see from the pitting it has been rusting from this side out, and depending onth eother side it might be outside in.
The sound/body deadner/ carpet was probably the true culprit, water ingress through use, leaking seals, door and windows, heater bubble, split seams etc gets trapped against the steel by the aformentioned stuff and works its magic.
very common problem for escorts as you know.
My fear about not cutting it out and welding a new pioece in is it wil keep rusting no matter how many chemicals you add. the steel is already damaged and very suceptible to further rust.
As I am replacing the exact same part on my Mk1 I know how difficult this part is to make.
good luck
 
Justin

POR, is a great system, hard to implement on a car that you don't want to strip to a bare shell.
Penetrol, is an oil, that creeps/migrates converting rust as it goes, when dry apply a primer. brush or
spray on. parts that are rusted through are still treated by replacing weakened areas welding in patches.
 
The areas, where we can't see the rust, i.e. chassis rails etc, Please list and post the areas where we/you
cannot see the Rust.  I intend to calculate the internal surface area, of a, say a chassis rail, drill a 2mm hole,
and inject X mils of Penetrol, with a Suringe. I've a new bare metal guard that i can use to see the area 
covered by applying, X mils of Penetrol, to this quantity, i will add 30%. My base line.!! as a backup i'm
adding Electronic Rust Prevention, confident that my Mk2 won't be off to a scrap yard, in the next 37 years.!!!
 
Cases containing Air Conditioners, on the Gold Coast, salt air, humidity all that stuff, a new 18 story building
installed ERP, Customer was happy with the air cons performance, 6 months later, Rust, (not happy joyce)
No one turned on the Electronic Rust Prevention.  … … Made me smile, must be my warped sense of humour.
 
Cheers Geoff

Another possibility that I have seen is water tracking down the antenna wire at this location.