Identifying Rust: A Buyer's Guide to Classic Car Bodywork

Mechanical problems can usually be fixed. Electrical gremlins can be traced. But rust — rust is the cancer of classic cars. Left unchecked, it spreads until repair costs exceed the vehicle's value.

The Three Types of Rust

Surface Rust

Cosmetic only — affects the paint layer and very top of the steel. Easily treated with sanding and proper preparation.

Scale Rust

Progressed deeper into the steel. The metal surface is pitted and rough. Can be treated but requires more aggressive intervention.

Penetrating Rust

Through the steel. Holes form, structural members weaken. Repair means cutting out and welding in new metal. Expensive.

Where to Look: The Usual Suspects

Sills (Rocker Panels)

Poke firmly with a screwdriver at the base of the sill. Sound metal resists; rotten metal crumbles. Look for bubbling paint or fresh underseal.

Wheel Arches

Feel inside the arch with your hand. Compare both sides — asymmetry suggests repair or ongoing problems.

Floor Pans

Lift all carpets and sound deadening. Poke suspected areas. Fresh underseal is a red flag.

Door Bottoms

Run your finger along the bottom edge. Feel for roughness or thin spots.

Boot (Trunk) Floor

Remove all contents and liners. Check particularly around the edges.

Red Flags: Signs of Hidden Problems

Fresh underseal: Often applied to hide problems
Paint bubbling: Rust pushing from underneath
Misaligned panels: May indicate rust in structural areas
Evidence of filler: Use a magnet to check panels
New carpets in old cars: Why were they replaced?

Pre-Purchase Inspection is Worth It

For any classic car over €10,000, a professional pre-purchase inspection pays for itself. Expect to pay €200-400, but that's cheap compared to discovering €5,000 of hidden rust after you've bought the car.

On Finds, we encourage sellers to provide detailed photos of known problem areas and disclose previous repairs.

Finds is built by BetterQA. We believe in transparency — sellers must disclose known issues.