Rust on lower inner edge of sill/arch.

[Ian Lanc]

Getting a little fed up with treating our Fiesta with care now, this is the third time I'm going to have to do this 🙄

Last year I went to town on the lower edge of the sill, used a wire flap disc on the angle grinder, completely removed every bit of rust.

Then applied several layers of that rust killer stuff, the stuff that turns black.

then applied two layers of etch primer.
then a good layer of yellow primer filler.
then grey primer.
then two layers of ford green.
then three layers of clear lacquer.

I thought that would be the end of the rust problem but oh no It's coming back again,
the image is how it looked when I'd done the job, but the area marked out in red
is where the rust is coming back, can't believe it's coming back if I'm honest,
must be the battering it gets by water & grit, so fed up with it all now.

Is there anyone in the group who has mastered the art of killing rust for good ? Advice ?

I've thought of using the wire brush on the angle grinder again, then leaving the steel raw and just slapping thick grease over the bare metal ?

[Ian Lanc]

Or do I use the wire brush attached to the angle grinder, bring back to bare steel,
then several coats of underbody seal, I've got five cans of it in the shed!

So pee'd off with it all 😳 I'm not in the greatest health in doing such maintenance these days 🥴
 

[isetta]

I would clean it up and give it a few coats of hammerite, not the undersealer stuff, I mean the glossy hammered finish stuff

[Ian Lanc]

57 minutes ago, isetta said:

I would clean it up and give it a few coats of hammerite, not the undersealer stuff, I mean the glossy hammered finish stuff

Could be a better plan, the glossy hammerite is a better option than the black tacky underseal stuff, Think I've some hammerite in the shed.

Thanks 👍

[Eric Bloodaxe]

2 hours ago, isetta said:

I would clean it up and give it a few coats of hammerite, not the undersealer stuff, I mean the glossy hammered finish stuff

Yes, I've used Hammerite in preference to underseal in abraded areas, and it worked ok. Plenty of colours available too, so can be fairly inconspicuous in hard to see areas. 

[jace1969]

I have the same problem and it's the same spot and mainly on the driver's side,i can also see small bits starting on the arch from the bottom.

It's amazing as i did the same,removed all the rust and put that primer that turns black and a thick normal primer and paint, lasted about 6 months.

[Ian Lanc]

3 hours ago, jace1969 said:

It's amazing as i did the same,removed all the rust and put that primer that turns black and a thick normal primer and paint, lasted about 6 months.

It gets me down a bit in these times, I suffer with Spondylosis of the lower spine so bending over or kneeling isn't advisable nowadays.

This is what I faced with last year and really did a great job in getting it sort, know what I'm doing to be honest but rust coming back is a joke.

[Ian Lanc]

3 hours ago, jace1969 said:

It's amazing as i did the same,removed all the rust and put that primer that turns black and a thick normal primer and paint, lasted about 6 months.

This was the end result after a weekend, both lower sills looking like brand new, I was proud of my work, that was until I spotted the rust.

[jace1969]

I thought i got out of these jobs when i sold my older cars.

Ok mine is just over 11 years old so i do expect some, but it gets me that as you said you spend hours on it and it just comes back.

[Ian Lanc]

2 hours ago, jace1969 said:

Ok mine is just over 11 years old so i do expect some

Been to the supermarket this morning and looked upon an 09 Fiesta, so decided to have a look if that Fiesta has rust,
indeed it had, but it was much worse than mine, rust well up on the sills at the rear and the bottom of the arches was
mental, it was literally a mass of rust and looked very bad, I reckon if I'd not worked on our car It would be the same.

[Mavroz]

My old Focus Zetec Z was riddled with rust all around the rear wheel arches.

That forced me to get rid, a bit earlier than I probably would have done.

[Ian Lanc]

Well the rust is well and truly back again, even after applying hammerite anti corrosion paint, its back, getting to the point of just removing all the rust and spraying an inch worth of hammerite anti-rust coating on the sodding ends.

[KenM]

Biggest problem is the rust is in between the skins which you can’t get at to treat plus some may be coming through from the inside. Another thing is when you use the rust killer and it goes black do you clean that off with a wire wheel before you treat again, you sometimes need to do that a few times to fully penetrate the rust the wire wheel again before etch primer and try to make sure you don’t sand through the etch primer before priming.

[bertj]

If you don't mind this is slightly off topic?

I've got a relatively new Titanium X (2020). Are newer Fiesta's also prone to rust developing in the same places? 

Is the cause of the rust made worse by mud etc. thrown up from the road? If so would front mud flaps be a good idea?

BTW, genuine Ford mud flaps seem very expensive for a couple of pieces of plastic!  

[Tiexen]

2 hours ago, bertj said:

If you don't mind this is slightly off topic?

I've got a relatively new Titanium X (2020). Are newer Fiesta's also prone to rust developing in the same places? 

Is the cause of the rust made worse by mud etc. thrown up from the road? If so would front mud flaps be a good idea?

BTW, genuine Ford mud flaps seem very expensive for a couple of pieces of plastic!  

Don't forget these are 10 - 14 year old cars, I think your OK till 2030 - Your EcoBoost engine will probably go first!

[Ian Lanc]

On 2/6/2023 at 7:09 PM, KenM said:

Biggest problem is the rust is in between the skins which you can’t get at to treat plus some may be coming through from the inside. Another thing is when you use the rust killer and it goes black do you clean that off with a wire wheel before you treat again, you sometimes need to do that a few times to fully penetrate the rust the wire wheel again before etch primer and try to make sure you don’t sand through the etch primer before priming.

I'm having both ends of the sills sand blasted, in a hope every bit of rust is removed, then i'll repaint again.

[Mavroz]

Focus Zetec S a few years back now started scabbing along the rear wheel arches at around 9 years old.

Body shop said they could get it back to normal treating with rust stop etc but said it would 100% definitely come back through within the next 12 months or so. They would not give any guarantee whatsoever and it was a well-used reputable company who were honest and just didn't take the money (£160 at the time for both arches.) Something to do with felt wheel arch liners causing the issues.

Got rid of the car a couple of months later, someone else's problem.🤣