Shot blasting is a form of material finishing that uses a stream of small steel pellets, or shot, propelled at high velocity to smooth or roughen a surface, clean it or remove contaminants. The equipment used is highly specialized, and the type of shot used can be calibrated to carry out the intended purpose without waste or damage to the material being cleaned. A typical shot blasting system consists of an air compressor or other source of propellant, a magazine containing the shot, and a wand or other applicator, all connected by hoses. Some systems include the ability to inject soapy water into the shot stream in order to cleanse and degrease the surface as part of the process.
This technique is best used for durable objects, such as concrete walls and pillars, body parts of automobiles, and swimming pool tiles. The force used to project the shot is not suitable for small or delicate items, since the purpose of the shot blasting is to remove contaminants or surface materials that cannot be economically removed in any other way.
The key criterion for shot blasting work is the ability of the surface material of the product to be able to withstand the impact of the shot without deforming. Consequently, this process is best left for steel or iron products, sheet metal, concrete or tile. It is important to consider omitting as many tight corners or irregular shapes as possible, as the shot have difficulty penetrating these spaces consistently.
Many construction firms offer shot blasting services as part of their menu of potential work to be done, as it is often part of a building project. Other places this work can be done include auto body shops and metal foundries, which use shot blasting to finish rough castings. Shot blasting quotes may be obtained from any of these sources in order to determine the cost and time to have the work done. While the actual process of shot blasting is very noisy and can be spectacular, with clouds of dust and sparks being emitted, it is actually a fast and efficient way of cleaning and preparing or restoring a surface.