Rust protection and corrosion

A repair is only successful when it also holds over time. Rust is the body technician's silent opponent: it often begins invisibly and eats inward until the panel is rusted through. Therefore rust protection is not a finishing detail but an integral part of professionally correct work.

§How does rust form

Corrosion on steel typically requires three things: metal, oxygen and moisture. Where they meet iron is slowly converted to rust which takes up more space than the metal and thus explodes the paint from inside. Salt from roads accelerates the process and places where water and dirt accumulate rust fastest. Scratches in paint and bare metal edges after repair are therefore prime attack points if not protected.

§Protection begins at bare metal

When you've ground down to bare metal or replaced a part the surface is unprotected. A suitable primer or undercoat lays the first protective layer that both adheres to the metal and gives the paint something to grip. Welded joints and edges need special attention because heat has removed the original protection right there.

Exposed places on the car.

• 01Wheel arches and lower door edges where water and salt splash up.
• 02Cavities in doors, sides, and beams where moisture collects unseen.
• 03Weld seams and overlapping plates where water can penetrate.
• 04Stone mark-exposed surfaces on undercarriage and front bumper.
• 05Areas where drain holes are clogged so water gets stuck.

§Undercarriage and transition to lacquer

The undercarriage is exposed to rocks water and salt and is often protected with a stone chip and undercarriage treatment that both dampens and protects. Most important is that the protection is applied in the right order: clean surface correct primer any joint sealing and finally lacquer or protective mass. If a step is skipped the chain breaks and rust finds its way.

§The long perspective

Correct corrosion protection is what distinguishes a repair the customer forgets from one that comes back in a couple of years. Follow manufacturer's and product instructions and protect everything you expose during work. Think of it as invisible craftsmanship: no one sees it but everyone feels the difference when the car holds up.