Hammerite is the direct-to-rust enamel paint that has been the established workhorse product for chassis and underbody protection on British classics for decades. The headline property is in the name, the paint can be applied directly over surface rust, without primer, after only a wire-brush preparation to remove loose flakes. The active components in the paint chemically convert the residual oxide as the enamel cures, producing a stable rust-resistant surface in a single application step.
For owners working on chassis components, suspension brackets, brake backplates and the wider range of underbody steel, Hammerite turns a multi-step preparation job into a single-coat operation.
The Hammer Finish
The hammer finish, the textured, slightly-metallic appearance that the product is named for, is achieved through a special blend of resins, pigments and metallic flake that flows together as the paint dries to produce the characteristic pattern. The texture is genuinely functional as well as aesthetic: it hides minor surface imperfections that a smooth gloss enamel would highlight, and it gives the workmanlike appearance that suits a restored chassis without trying to make it look factory-new. The finish is durable in service, resistant to chipping under stone-strike, stable in UV exposure, and forgiving of the slight movement and flex that a chassis sees in normal use.
Smooth Finish, Colour Range and Application
Hammerite is also available in a smooth-gloss finish for owners who prefer a more traditional paint appearance on visible components. The colour range covers the standard black for chassis and underbody work, dark green for engine-bay items, silver and aluminium for polished-look chassis components, and the various grey and primer-look finishes for items that need to disappear visually. Aerosol Hammerite suits touch-up and small-component work, refinishing a brake backplate, painting a bracket, the various spot-application jobs that come up during restoration. Tin Hammerite is applied by brush or roller for larger areas, with conventional brush technique giving the cleanest result.
The paint dries quickly to handle, but full cure to the hardest service finish takes several days at workshop temperature.
Preparation and Limitations
Wire-brush preparation removes loose flake rust and oily contamination before painting, the paint will not bond to a surface coated in grease, brake fluid or aged Waxoyl. Where a smooth primer with anti-rust properties is wanted under a topcoat rather than a direct finish, Hammerite No.1 Rust Beater is the dedicated primer product, applied over prepared steel as the base layer for subsequent paintwork. Heavily-pitted or scaly rust where the metal is structurally compromised is not the right application for direct-to-rust paint; in those cases the right answer is metal renewal, not painting over. For the surface rust, light pitting and accumulated oxide that any classic chassis carries, Hammerite is the established solution.
The product is not designed for high-temperature applications, exhaust manifolds, downpipes and the immediate area of the exhaust system need the dedicated high-temperature paint covered under Other Spray Paint.