The surface should be clean, dry and grease free. Degreasing of most galvanised surfaces requires some effort to obtain a clean surface. Any white zinc corrosion products should be removed by high pressure fresh water washing, or fresh water washing with scrubbing. A surface suitable for coating will ideally be prepared by sweep blasting but it is still advisable to fresh water wash to remove soluble zinc salts. A pre-treatment with Dulux Professional etching primer is recommended.