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Get to Know the Process of Bead Blasting

Get to Know the Process of Bead Blasting

Bead blasting can be used for both, polishing a surface as well as for removing cosmetic defects from it. In this ScienceStruck article, we shall understand the unique concept of bead blasting, explore its types, and have a look at its typical applications.
Satyajeet Vispute
Safety Tip
Abrasive cleaning including glass bead blasting creates a lot of dust and noise. The dust has the potential of causing lung damage, while the noise can affect hearing. Hence, it is advisable to wear protective air masks as well hearing protection while on the job.

When you send your old furniture off for polishing, you can expect one of the following two things to happen - either they will come back reborn, all sparkling and shining, or they will be so cracked and damaged that you will end up performing their last rites! Such are the perils of abrasive blast cleaning. However, there is one particular blast cleaning type which is considered to be safe for cleaning older and weaker surfaces.

Glass bead blasting, as it is called, is a considerably milder cleaning procedure, which is more likely to prolong the life of your old and rusted possessions, rather than abruptly end it. In the following lines, we go into the details of the glass bead blasting process, and tell you why it can be the right choice for your possessions. But first, let us understand what abrasive blast cleaning means.

What is Abrasive Blasting?
Abrasive blasting is a process used to clean, polish, or reshape a given surface. In it, air compressed to a high pressure is used to propel an abrasive media onto a surface to roughen/smoothen it, or to remove any surface contaminants.

The basic idea behind this technique is to do a controlled amount of damage to a material without making it unusable. Commonly used abrasive media for blasting are coarse sand, water, glass beads, air, and even dry ice.

What is Bead Blasting?
Bead blasting is a form of abrasive surface cleaning. It utilizes pressurized air to blast a jet of beads onto a surface in order to remove any unwanted coatings or layers off it. The beads used are usually spherical in shape, and as such, the damage done to the surface is significantly lower as compared to other types of abrasive blasting techniques.

Many different types of beads are used for blasting. These include glass beads, plastic beads, stainless steel beads, and silicon carbide beads. Each type offers a different level of abrasive property as compared to the other. Spherical glass beads are typically used for more delicate surfaces, as they are less abrasive, and therefore known to cause the least amount of damage. The process of polishing using glass beads is termed as 'peening'. Blasting with other types of beads is quite similar to peening. So to understand the common procedure, let us look at what peening a surface involves.

The media used in peening comprises spherical glass beads that are added to a bead blasting machine, which fires them out at high velocities to impact the intended surface. The surface to be cleaned is placed at the machine's line of fire, and the beads are shot at it. The impacting beads gently abrade the surface, removing contamination and effectively cleaning it.

The beads used in peening are made of soda-lime glass. They are also lead-free. Both these attributes make peening a relatively environment-friendly process. Also, after the process is completed, much of the beads can be recovered using a vacuum cleaner. These beads are pretty tough, and can be recycled several times. This reduces the waste that is produced during each blasting cycle.

Peening causes very little damage to a surface. Therefore, it can be used on old and delicate materials such as wood and softer metals. It is also most commonly used in cleaning electrical connections, and welds and solders in electrical circuits that would be damaged if other more aggressive types of blast cleaning methods were to be used.

Bead Blasting Types and Applications
The process of bead blasting is classified into dry blasting and wet blasting, based upon the type of fluid used to propel the beads.

Dry Bead Blasting
Dry blasting utilizes air to propel the beads. Hence, it is also known as air or pneumatic blasting. Air blasting is considered a comparatively cheap process, as the pneumatic tools used for it utilize low amount of energy. Also, the beads themselves are pretty inexpensive.

Air blasting is used extensively in the automobile sector for cleaning metals such as aluminum and stainless steel. It is used to polish items made up of softer materials, including copper, silver, and brass. It is also used for removing rust, correcting surface flaws, and for readying a surface for painting.

Wet Bead Blasting
This process uses beads blasted using a pressurized (water + soap) mixture for cleaning a material. It uses even lesser energy than pneumatic bead blasting, and the beads mixed with water are easier to clean up after the process is completed.

In wet bead blasting, both, the beads and the water work together to enhance the cleaning capability of the process. This allows it to be used for cleaning rough surfaces, such as granite and concrete. At the same time, it is also suitable for cleaning relatively softer surfaces, such as sandstone or bricks.

Finishes and Final Words
Bead-blasted surfaces display medium levels of finishes. They are definitely much cleaner and shinier than the non-blasted ones, but fail to achieve the high-gloss polish that, say, for example, sand blasting provides. However, the main advantage of this technique lies in the fact that it does the least amount of damage to the surface or the material being blasted. Also, it has been found that bead blasting causes compaction of metals, making them harder and more resistant to stress and fatigue.

Thus, bead blasting is a gentler abrasive cleaning process that works well on softer surfaces and delicate materials. It isn't too expensive to employ, and can help you get back the lost luster and shine on your old or soiled possessions.