Grit Blasting uses grit, propelled at high velocity by compressed air using an ejector system. It is the tried and proven method of dry docks.
It is an effective method of achieving a suitable profile for a new coating to adhere to. It can be used to remove mill scale on new steel or rust and old coatings from old steel. It will not clean salt or other contaminants from the steel and so must be used in combination with High Pressure washing or Blasting on old or dirty substrates.
Advantages
- Relatively fast
- Good for localized as well as full blasting
- Relatively inexpensive equipment
- Good for feathering coating edges
- Good 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
