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Rust proofing and undersealing the van

Many older vehicles (especially vans) don’t have much protection against rust on the under side where it’s exposed to the elements and harsh conditions. I used the Hammerite underbody seal (this one) on all of the underside floor panels of my van, including the wheel arches. The example below just shows the wheel arch.


The picture probably looks worse than it actually is (although I have to think that). Most of the bad rust is on the panels–the chassis looks in great nick with only a few patches of surface rust. I highlighted the worst of it in this post fixing the floor rust on my LDV

1. Clean area

After removing all loose bits of rust and dirt I cleaned the area with a detergent and a scrubbing brush to remove grease and oil. Then I removed loose bits of rust with a wire brush attachment on the drill.

This is a very time consuming job but it’s worth spending time to do it properly. It’s probably best to divide the area up and work on one section at a time.

Cleaning the wheel arch
Cleaning the wheel arch

2. Rust treatment

I used a paintbrush to apply the rust treatment just like I showed you in the post about removing rust

Appling rust treatment to wheel arch
Appling rust treatment to wheel arch

3. Paint

I used 2 coats of metal paint. Again, this is just the same as the previous section on treating surface rust.

Painting wheel arch
Painting wheel arch

4. Underseal

I applied two fairly thick coats of the Hammerite underbody seal with a brush, leaving it for one day before applying the second coat. This stuff takes a few weeks to fully set, leaving a tough flexible layer

Undersealing wheel arch
Undersealing wheel arch

5. Repeat over whole underneath area


Hopefully this will provide a few years of protection

Feel free to add any comments or suggestions 🙂

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