Hammerite One Coat Kurust is a water-based primer that transforms rust into a sound surface in 15 minutes. It is ideal for small areas of rust, stone chips and scratches. Kurust is simple to apply, without the need for rinsing. No primer or undercoat is required, and a top coat can be applied after only 3 hours. Kurust works by converting iron oxide to stable iron complexes and turns a blue-black colour whilst doing so.HMMOCK90 in a 90ml blister pack.Additional Information:• Treatment Type: Rust Treatment• Colour: Black/Blue• Size (ml): 90