Before ships are scrapped, the removal of rust and other marine growth is an essential step to prepare the vessel for dismantling and recycling. This process involves various methods and techniques to ensure safe and efficient rust removal. Some common methods include:
High-Pressure Water Blasting: High-pressure water blasting, also known as hydroblasting, involves using pressurized water to remove rust, paint, and other contaminants from the ship's surface. The water is typically sprayed at extremely high pressures, which can effectively clean the metal without causing damage.
Abrasive Blasting: Abrasive blasting, such as sandblasting or grit blasting, is another method used to remove rust and old paint from the ship's surface. During this process, abrasive materials, such as sand or steel grit, are propelled against the metal surface at high velocity, effectively stripping away the rust and other coatings.
Chemical Rust Removers: Chemical rust removers or rust converters can be applied to the rusted areas to convert the rust into a stable compound that can be easily brushed or scraped off. These chemicals work by converting iron oxide (rust) into a different chemical compound that can be rinsed away.
Mechanical Tools: In some cases, hand tools and mechanical equipment may be used to remove stubborn rust from smaller areas or hard-to-reach spots on the ship's structure.
Scraping and Wire Brushing: Hand scraping and wire brushing are manual methods used to remove loose rust and flaking paint from the ship's surface. While they may not be as efficient as other methods, they are often employed for detailed cleaning in smaller areas.
Corrosion Inhibitors: To prevent rust from forming again quickly, corrosion inhibitors may be applied to the cleaned metal surfaces. These inhibitors create a protective barrier that helps to delay the onset of rust.
It's important to note that the removal of rust from ships for scrapping is a careful and labor-intensive process. Safety measures must be followed to protect workers from potential hazards associated with rust removal and the handling of old ships, such as lead-based paint and other toxic substances. Additionally, environmental considerations are taken into account to prevent pollution and properly dispose of any waste generated during the rust removal process.