First wet the surface, then apply Lithofin MN Builder’s Clean – diluted with water up to 1:10, depending on the type of dirt – and immediately spread the product evenly on the surface with a scrubbing brush. After a few minutes, scrub the surface then wash away with clean water. Do not allow the product to dry on the surface. In stubborn cases this procedure may have to be repeated. Advice: in case of extremely stubborn, repeated rust discolourations we recommend Lithofin BERO. Please Note: Lithofin MN Builder’s Clean is not suitable for polished or finely honed surfaces which are sensitive to acid such as limestone, marble, manufactured stone, etc. In cases of doubt, try the product in an inconspicuous area. Surfaces such as chrome, enamel, wood, and similar acid sensitive surface must be protected against splashes and vapours. Acid containing cleaners can develop vapours which may damage sensitive surfaces. We highly recommend carefully washing the product off the surface and ensuring good ventilation during and after use.