Grit blasting is a common surface preparation method used in various industries, such as shipbuilding and maintenance. It involves using compressed air to propel abrasive grit particles onto a surface, which creates a roughened surface profile necessary for proper adhesion of a new coating.

Grit blasting is effective in removing mill scale, rust, and old coatings from steel surfaces, making it a suitable technique for preparing surfaces before applying new coatings. However, it is important to note that grit blasting does not clean contaminants such as salt from the steel, so it should be used in combination with other methods like high-pressure washing or blasting for old or dirty substrates.

Advantages

• Relatively fast
• Good for localized as well as full blasting
• Relatively inexpensive equipment
• Good for feathering coating edges
• Great for creating an ideal profile for coating adherance
• The prefered method of most shipyards

Disadvantages

• Requires a lot of compressed air.
• Dirty and difficult to contain grit and dust
• Locks in salts in the substrate so surfaces must be high pressure cleaned as well
• Clean up costs for used grit
• Dumping costs for used grit