In order to offer guarantees on structural metal, it requires cleaning to Sa3 standards and inspections from a certified NACE inspector. As this is not always possible, cleaning to ST2 with subsequent Dekro Representative inspections will provide a 7 to 10 year life expectancy of the coating system but excludes rust returning during the life expectancy of the coating.
Sa 3 Cleaning: Blast cleaning to white metal. The jet passes over the surface, long enough to remove all mill scale, rust, and foreign matter. Finally, the surface is cleaned with a vacuum cleaner, clean and dry compressed air, or a clean brush. It should then have a uniform metallic colour.
St 2 Cleaning: Thorough scraping (with hard-metal scraper) and wire brushing – disc-sanding – etc. During the operation all the loose scale, rust and foreign matter should be removed. Finally, the surface is cleaned with a vacuum cleaner, clean and dry compressed air, or a clean brush. It should then have a faint metallic sheen.
Once areas were thoroughly cleant, two coats of Hydromet Rust Converter were applied over the rusted areas which has excellent rust converting properties and prevents the migration of rust through to the paint film.
Two final coats of Hydro C5 (Direct to Metal water based coating) was applied which is an anti-corrosive coating suitable for C5 industrial environment – buildings or areas with almost permanent condensation and high pollution.