Silly Rust Stains

tony glenn

Is there a long-term solution to prevent rust stains appearing in my (white) 2004 Ford Transit sills? Initially I was applying rust preventer then painting over. That only worked short-term, so then I cleaned the areas, painted with underseal, and painted over again. That worked for longer, bit the stains are showing again now. There's no outward sign of serious rust btw.
I'm considering drilling holes in the top po the sills, drying them 'inside' and then filling them with expanding foam to prevent moisture ingress. Then repainting as usual. Any advice or suggestions appreciated. Apart from selling it lol.

kadman

Expanding foam will seriously compound the issue, and make it rust heaven

If you are getting ongoing rust issues, then you have some element of rust
in that area. The only way to stop it for sure is to remove the rusted metal.
Any other method is only postponing the inevitable.

Fertan is an excellent method of rustproofing, along with a few other good products.
But the best starting method is to find the source of the rust, cut it out and replace
it with new metal.

CJhaughey

tony glenn wrote: »

Is there a long-term solution to prevent rust stains appearing in my (white) 2004 Ford Transit sills? Initially I was applying rust preventer then painting over. That only worked short-term, so then I cleaned the areas, painted with underseal, and painted over again. That worked for longer, bit the stains are showing again now. There's no outward sign of serious rust btw.
I'm considering drilling holes in the top po the sills, drying them 'inside' and then filling them with expanding foam to prevent moisture ingress. Then repainting as usual. Any advice or suggestions appreciated. Apart from selling it lol.

Expanding foam will hold water and cause worse issues.
The sill must be rotten inside if the rust keeps coming back.
Try some rust removal gel like Bilt hamber Deox and then a rust converter then Zinc paint then topcoat.
Those Transits do like to turn brown though.

tony glenn

tony glenn wrote: »

Is there a long-term solution to prevent rust stains appearing in my (white) 2004 Ford Transit sills? Initially I was applying rust preventer then painting over. That only worked short-term, so then I cleaned the areas, painted with underseal, and painted over again. That worked for longer, bit the stains are showing again now. There's no outward sign of serious rust btw.
I'm considering drilling holes in the top po the sills, drying them 'inside' and then filling them with expanding foam to prevent moisture ingress. Then repainting as usual. Any advice or suggestions appreciated. Apart from selling it lol.

Thanks. I've just noticed my headline typo, that should read Sill Rust Stains'....

tony glenn

CJhaughey wrote: »

Expanding foam will hold water and cause worse issues.
The sill must be rotten inside if the rust keeps coming back.
Try some rust removal gel like Bilt hamber Deox and then a rust converter then Zinc paint then topcoat.
Those Transits do like to turn brown though.

Replies appreciated. Maybe I should have bought a brown Transit in the first place....

rex-x

transits rust from the inside out, you have more serious rust than you think!

case_sensitive

On the good news side, the sills for transits are daftly cheap, probably because they do like to sponge up water and self-tan.
https://www.carbodypanels4u.co.uk/ford/transit/ford-transit-2000-2006-mk6/door-front-sill-12148

Obviously cutting and welding is going to be the harder or more expensive part, depending on if you have a crack yourself or bring it to someone more qualified.

I have the sills on my first car (Ford Puma) cut and shut extremely cheaply a few years back, mate's rates sort of a thing, but I don't think it was even €50. I did the prep and finish (grind it back pre and prime, underseal post) to save a few bob.