How should the surface of components be treated before painting during dry-docking repairs on ships?

How should the surface of components be treated before painting during dry-docking repairs on ships?

1. During dry-docking repairs at a shipyard, the first step is to wash the hull with high-pressure fresh water to remove salt deposits from seawater. After that, the surface is treated using sandblasting (also known as shot blasting or colloquially as “sandblasting”) to remove rust scales and any peeling paint. Once this is done, the ship’s paint representative, the ship's technical representative, or the ship owner must inspect the surface to ensure it meets the required standards before proceeding with painting.

2. In areas where sandblasting is not possible or not necessary (such as small areas), rust can be removed using grinding or scraping methods. Scraping is typically done with tools like rust hammers, scrapers, and wire brushes by hand, while mechanical grinding usually involves pneumatic tools, such as pneumatic hammers, grinders, or rotating metal parts. After rust removal, the surface should be cleaned with compressed air to blow off any dust. It's even better to wash the surface with fresh water afterward.

3. For two-component paints, the surface must be roughened before painting to improve the paint's adhesion to the surface.