Rust and Corrosion Repairs: Why It Happens and What to Do

How rust gets started

Corrosion needs bare metal, moisture and oxygen. A stone chip, a scratch, a poorly repaired dent or a seam where water collects can all expose steel. Once that happens, rust begins to form and can creep under the surrounding paint, lifting it into small bubbles.

Road salt makes the problem worse because it speeds up the chemical reaction. Salt air near the coast does something similar over time, and mud packed into hidden areas keeps things damp long after the weather has cleared.

Wheel arches, sills and other usual suspects

Wheel arches take spray and stone chips all day long. Sills sit low and collect road dirt. Door bottoms, boot lids, the edges of bonnets and the area around fuel fillers all have seams and folds where water lingers. Underneath, subframes, suspension mounting points and the chassis itself are exposed to everything the road throws at them.

A quick check once or twice a year is worthwhile. Look for paint bubbling, orange staining, flaking underseal and soft or crumbling edges when you press gently.

• Bubbles or blisters in the paint along arches and sills
• Orange-brown staining around seams and trims
• Flaking or cracked underseal
• Door bottoms and boot edges that look rough or swollen
• Corrosion on exposed brake pipes, mounting points or the chassis

Surface rust or structural problem?

Surface rust is early-stage corrosion that has not yet eaten into the metal in any serious way. It can usually be treated by removing the rust, treating the area, priming and repainting. Caught early, it is a minor job.

Structural corrosion is different. When rust has weakened load-bearing areas such as sills, chassis members or mounting points for the suspension and seatbelts, the car's strength and safety are affected. It can also lead to an MOT failure. Never ignore soft, perforated or crumbling metal in those places, and have the car looked at promptly.

What a proper repair involves

A genuine repair removes the rust rather than covering it. Thin patches may be ground back and treated. Where the metal has rotted through, the damaged section is cut out and new steel is welded in. That is why welding and structural repairs sit alongside rust and corrosion repairs in a bodyshop.

After the metalwork, the area is sealed, primed and painted to match. A quick bodge with filler and paint can look fine for a few months before the rust reappears, so ask what will actually be done.

Chassis and restoration work

Chassis repairs are a more serious category because the chassis is the backbone of the vehicle. They need careful assessment and correct repair methods. Whether a vehicle is worth repairing depends on how much corrosion is present, where it is and what the vehicle is worth to you.

Some owners come to us with older vehicles they want to keep going, and vehicle restoration can bring tired bodywork back to a good standard when the metal is dealt with properly first. Whether it is a sensible project depends on an inspection of the structure.

Slowing it down afterwards

Fix chips and scratches early, wash the car regularly in winter, and pay attention to the underside and the arches, where salt collects. Make sure drain holes in doors and sills are not blocked with debris. Keeping the car dry in storage helps too.

At Banks of the Tyne in Hebburn we can inspect corrosion, explain whether it is cosmetic or structural, and carry out the bodywork, welding and paint in one place. Ask us at the estimate what we can see and what we would recommend.

Frequently asked questions