What Does Open Abrasive Blast Cleaning Mean?
Open abrasive blast cleaning removes rust flakes or any other contamination from a surface. In this process, loose abrasive media propelled by compressed air is directed against the surface to be cleaned. This process has a wide range of applications for surface preparation, such as:
- Rust and scale removal
- Anchor pattern creation prior to bonding or coating
- Cosmetic finishing and coating or contaminant removal
This process helps to remove any rust and clean the surface before applying a coating, paint or adhesive, any or further corrosion protection method applications.
Corrosionpedia Explains Open Abrasive Blast Cleaning
Open abrasive blast cleaning uses an air compressor. A pressure regulator is used to control the air speed of the air compressor. The air compressor supplies high-pressure air for the blasting operation. Determining the volume of the air/media mix is done by the opening diameter of the nozzle with pressure blast systems, or the air jet diameter of the suction blast gun body. Caution is advised when using dry air, which prevents moist abrasive material, because it may cause increased wear and downtime, as well as additional servicing.
Open abrasive blast cleaning equipment has the following major components:
- Air compressor
- Blast pot (pressure blast tank)
- Abrasive (blast media)
- Blast nozzle
- Moisture trap
- Dead man's switch
- Blast hood
- Interconnect hoses
There are two types of equipment for air abrasive blasting:
- Suction abrasive blast equipment – Uses the Venturi principle to suction abrasives from a non-pressurized hopper to the blast gun. This equipment has two hoses (one for air and one for abrasives) running to the blast gun.
- Pressure abrasive blast equipment – Applies a pressurized vessel or “blast pot” that holds the abrasive media. In a pressure blast machine, the air pressure in the vessel and in the “pusher” line is the same. This equipment has a single hose running to the blast nozzle.
Direct air pressure blast-cleaning machines are used alone as portable units for site work, or they can be built into cabinets or blast rooms.