Sandblasting is a general term used in reference to abrasive blasting, which is a surface treatment technique that uses a blasting medium propelled under high pressure. The technique is used to clean surfaces though it can also be used to create decorative patterns or to apply coatings.
Back in the day, sand was the common medium for the blasting process. However, other materials have surpassed sand because it is too harsh, contains high level of moisture and different impurities, and has grains of different sizes. Some of the optional abrasive elements that can be used for sandblasting include:
- Coal slags
- Copper slags
- Crushed glass or minuscule glass beads
- Plastic media
- Corn cobs
- Chilled iron grit
- Aluminium oxide grit
- Walnut shells
- Coconut shells
- Steel grit
Each of the above abrasive medium has unique qualities that make it a better choice for certain blasting applications. For instance, to restore the lustre of a large surface made of sturdy materials, the blasting medium that should be used is aluminium oxide grit, which is the next best thing to diamond.
For applications that need a gentler approach, corn cobs are the ideal medium for the job. Corn cobs are commonly used to blast automotive parts such as engine parts. Certain surfaces are highly prone to damage if they are subjected to high pressure blasting using abrasive materials; for such surfaces, plastic is the ideal medium for the job.
Common Applications of Sand Blasting
In general, abrasive blasting is used to etch or clean surfaces. However, the technique is used for different applications, which include:
Sandblasting makes it easy to clean very large surfaces, especially those exposed to various natural elements all year round. A good example is when cleaning hulls of ships, massive concrete walkways, ancient architectural structures or building, and other large structures. Abrasive blasting can also be used to clean small to medium-sized surfaces made of metal, glass, or stone.
Cleaning various surfaces will require different blasting techniques; some would need high blasting pressure while others would require that the blasting be done at specific angles. When cleaning small surfaces or objects, a unique equipment called a blasting cabinet is used.
2. Priming Surfaces For Painting
As a cleaning technique, sand blasting is used for priming surfaces for paint or sealant application. The blasting will knock off or loosen various impurities and imperfections, which will make the surface smooth and ready for a new layer of paint or sealant.
The automotive industry often uses it to prep vehicles for a fresh paint job. Common residential application of sandblasting includes the restoration of landscape-based furniture that have faded with time, and the cleaning of concrete walkways.
3. Decorating Glass
Since glass is brittle, it needs a delicate approach of blasting; it should be done at a slightly lower pressure. Blasting can be used to curve or etch glass.
- Curving glass using abrasive blasting is done through a stencil to keep unwanted areas of the glass from curving. The technique can produce different results especially when the glass is given different curves and cut in different angles at various depths; this could give an array of lighting effects.
In glass etching, the blasting turns clear glass into a semi-opaque surface. The technique is sometimes called glass whiting or glass snowing and is often used when doing calligraphy or various designs on the glass.