Marine Hull Sequence
Surface preparation in shipyards is governed by the harsh saline environment. To prevent "under-film" corrosion, the blasting sequence must achieve surgical cleanliness while managing chloride levels.
1. High-Pressure Wash
Removal of marine growth and salt deposits before blasting to prevent driving chlorides into the steel pores.
2. Sa 2.5 Technical Blasting
Using Garnet or Copper Slag to achieve a near-white metal finish with an anchor profile of 75-100 microns for heavy marine epoxies.
3. Dust Extraction & Verification
Immediate removal of spent abrasive and dust to allow for surface profile and chloride testing prior to primer application.
Ballast Tank Logic
Confined space blasting requires high-CFM ventilation and mandatory Grade D Breathing Air. Steel Grit or Garnet is preferred here to minimize dust levels and ensure Sa 3.0 white-metal cleanliness for long-life tank linings.
The Chloride Threat
Coastal humidity causes rapid "flash-rusting." Technical shipyard operators utilize high-capacity Moisture Separators to ensure dry air, preventing media clogs and ensuring the abrasive hits the steel with zero moisture-bound salts.
Coating Verification Sequence
- Profile Check: Using Profile Gauges to confirm mechanical bond prep.
- DFT Verification: Multi-point Digital DFT checks after each coating layer.
- Holiday Testing: Final high-voltage spark check for 100% lining continuity.