Garnet Sand – Preferred Abrasive for Shipbuilding & Ship Repair Blasting, Easily Achieves Sa3 Standard
Surface preparation of steel plates is critical for marine anti-corrosion coating performance. Because marine assets operate under harsh saltwater conditions, Sa3 (white metal blast cleaning) is widely specified for ballast tanks, decks and pipelines.
Garnet sand is the preferred eco-friendly abrasive to reach Sa3 grade. It features proper hardness and sharp angular grains, so it can thoroughly remove rust, mill scale, old paint and surface contaminants. As a result, the cleaned substrate fully meets the Sa3 criteria defined by ISO 8501-1 and SSPC.
Key advantages for marine blasting:
- Low chloride content which helps prevent pitting corrosion in saltwater environments;
- Low free silica and low dust, making it safer for confined ballast tank blasting;
- Consistent anchor profile, providing an excellent bonding base for anti-corrosion coatings;
- Minimal embedment into steel surface, thus reducing rework during inspection and painting;
- Recyclable, which can cut overall blasting costs for shipyards.
Grit selection:
- 20/40 mesh: For hull outer plates and thick steel, delivering a deeper anchor profile suitable for high-build coatings;
- 30/60 mesh: Universal grade for ballast tanks, pipes and profiles, and it is widely popular in ship repair projects.
In addition, stable Sa3 results depend on suitable blast pressure and nozzle distance. Therefore, salt testing and cleaning inspection are strongly recommended right after blasting. In summary, this abrasive is widely used in new ship construction, dry-dock repair and offshore steel structure blasting.
Tip: Stable Sa3 results depend on suitable blast pressure and nozzle distance. Salt testing and cleaning inspection are recommended after blasting. It is widely used in new ship construction, dry-dock repair and offshore steel structure blasting.