What is abrasive blasting?
Abrasive blasting refers to the operation of forcibly propelling a high-pressure stream of abrasive material against a surface in order to smooth a rough surface, roughen a smooth surface, shape a surface or remove surface contaminants.
It is a method used to clean or prepare surfaces prior to use. Abrasive blasting can be used to remove - or clean - excess or unwanted materials from a surface. The advantage of the procedure is that it keeps the surface intact, while everything else is removed.
There are two main types of blasting: dry and wet. The type of abrasive used in a particular application is usually specific to the blasting method. The exact equipment used depends, to a large extent, on the specific application and type of abrasive.
Abrasive blasting has been in use for over a century. A variety of blasting methods are employed by industries worldwide to remove paint & debris, prepare surfaces for paint & coatings, strengthen metal surfaces and adhesion, clean rust and grease, and engrave stone. Abrasive blasting offers significant cost and time savings over alternative methods. Additionally, blasting can replace the use of dangerous chemical strippers and solvents.
The selection of the correct abrasive blasting media type is critical. Abrasive media are divided into hard abrasives and soft abrasives. Hard abrasives include aluminum oxide, garnet, silicon carbide, steel shot, steel grit and glass beads. Hard abrasives are used to remove rust and scale from hard metals, introducing a profile to metal surfaces, and peening to strengthen metal surfaces.
Soft abrasives include walnut shells, plastic blast media, corn cob media, baking soda and wheat starch. Soft abrasives are used to remove paint and coatings from hard and soft metals such as steel and aluminum, as well as soft substrates including composites, fiberglass, rubber, plastics and wood. Soft abrasives, when used with the correct blast parameters, can safely remove paint and coatings from delicate surfaces without etching, marring or pitting. Abrasive blasting with soft abrasives are commonly used for paint removal from cars, trucks, trailers, boats, planes, trains, helicopters, military ground equipment and furniture.
All important for a successful abrasive blasting project are pressure or psi, nozzle distance, media type and media size. Each blasting operation requires careful calibration of these factors to ensure maximum efficiency without damaging surfaces or parts. Typically, harder surfaces with tougher coatings will use aggressive media at higher psi, while more delicate surfaces will require softer media at lower psi. Nozzle distances vary from 1-4 feet depending on surface, coating and media.
Additionally, prior to abrasive blasting, careful preparation and consideration must be given to worker safety. Typically, blasting workers wear protective body suits that include respirators to protect from dust inhalation. Due to the significant increase in decibel exposure during blast operations, workers also wear ear protection. With all dust forming operations, dust collection is key to prevent fires. Therefore, dust collection systems are essential for blast rooms and cabinets. Outdoor blast operations should be aware of dust safety and precautions.
Kelso offers abrasive blasting expertise in selecting the media and blast parameters best suited for your project. Our team is also trained in all safety precautions to ensure the success of your project. With offices in Milton and Ottawa, we are happy to service not only the Greater Toronto area and eastern Ontario, but also the entire of Ontario and beyond. Give us a call today.