Blasting is a common procedure use to treat the surfaces of many different kinds of objects. There are several different types of blasting, and they can be compared most easily to sandpaper. Some types of blasting are done using large blasts that are made to wear away large portions of material. Other types use very small materials that are designed to wearing away small patches with much more attention to detail. Glass bead blasting is a method using one of the largest types of blast media.
Blasting is the process of applying some type of grit or blast media to a surface, using pressurized air to propel it. As the media brushes against the surface, it wears the surface down and often takes away the top layer of material. Blasting is done to cars, metals, construction projects and many other things. Glass bead blasting, often referred to as simply bead blasting, is done using small glass beads which are often designed especially for the purpose.
A blasting system requires an air compressor, a blast media holder or hamper, and a nozzle. The air compressor takes nearby air and forces it through a hose at a specific pressure. Because of their size, glass beads typically require greater pressure than other media.The hamper holds reserve blast media and mixes it with the air at the proper time. The nozzle directs the media in a jet-like stream that can be effectively aimed. Blasting must be done in a tightly controlled area to avoid damage to the environment.
Blasting materials range from very large to very small. The smallest types of materials are sand and grit, small grains that excel at removing paint finishes or sanding objects smooth. Types of bicarbonate soda are also sometimes used. Large media range from crushed walnuts shells and crushed corn cob to harder types of media like glass beads. The beads are made from lead free, soda lime glass.
Types of Blasting
Glass beads are used for several different types of blasting, including finishing, cleaning, deburring and peening. Finishing refers to the process of texturing a material after it has already been coated, giving it a light burnish. Cleaning, of course, means removing caked-on grime and dirt. Deburring refers to smoothing methods in which bits of metal or other materials left from welding procedures are worn away. Peening is a process that lightly cracks the surface of some rigid materials to create a layer of cracks that actually helps increase the performance of some materials with compression stress.
Glass beads are popular for a couple of reasons. Like walnut shells, the beads are not harmful to the environment. Sand blasting media, on the other hand, contains trace amounts of silica that can be damaging to human lungs and surrounding plants. Also, sand media is very difficult to contain and reclaim, but glass beads can be cleaned up easily and recycled for continued use.
- glass beads image by Alison Bowden from Fotolia.com