On new or exposed metal surfaces: If you are going to use 3 in 1 Converter or Enamel, they can be applied on the oxide that is firmly adhered, otherwise it must be sanded until all the oxide is removed and two hands of Antioxide are applied before the enamel. termination. Antioxidant is not necessary, only when using 3-in-1 enamel, as it combines the properties of converter, anti-oxide and enamel termination in only one product.On surfaces that have already been painted: loose or peeled paint layers should be removed, roughened by sanding when the surface is very smooth and repaired properly. In both cases, take into account the general considerations.