Rustproofing has moved a long way from the sticky black tar of the 1980s. A modern protection system works in layers, each with a different job.
Layer 1: penetration. Thin, creeping fluids — like Mercasol 1 — are injected into cavities, seams and folds. They wick into the joints where corrosion starts, displace moisture that is already there, and leave a protective film inside the metal structure where no brush or spray could ever reach.
Layer 2: sealing. Waxier products build a soft, self-healing film inside cavities. Because the film never fully hardens, it does not crack when the body flexes — a key weakness of hard coatings.
Layer 3: armour. The exposed underbody gets a thicker coating that resists stone chips, abrasion and constant spray — products like Mercasol 3 and the underbody range.
Two things make the difference between a treatment that lasts and one that does not. First, preparation: the metal must be clean and dry before anything is applied. Second, coverage: the hidden 80% of the job — inside sills, doors, chassis rails — matters more than the visible 20% underneath.
Done properly, with the right products in the right order, a treatment protects for years, with a simple inspection and top-up cycle after that. Browse the system — or tell us what you drive and we will spec it for you.