Automotive Sand Blasters

Automotive Sand Blasters

Sand blasters are a very effective method of cleaning metal surfaces by using the abrasive characteristics of sand to scour them thoroughly. Regardless of how the blaster is supplied with material, the basic concept of all of them remains the same. Finely ground particles are ejected out of the nozzle at high velocity, and used to efficiently remove every trace of paint or rust that was present prior to use.

Sand blasters are relatively simple machines that perform a very useful task. Using finely ground silica sand traveling at high speeds, the sand blaster cleans exposed metal surfaces of rust, paint, or other material that is thinly coating it. The silica is able to clean off these materials because of the abrasive characteristics of this type of sand. The interior of the pressurized gun that is used to expel the sand is either coated with a protective layer that is resistant to the damaging abrasion caused by the use of the blaster, or it is made of a ceramic material that has these same qualities, in order to prevent the high-velocity sand from damaging the internal structure of the device over the lifetime of the sand blaster, which could compromise its effectiveness should leaks or other damage weaken the integrity of the sand blasters structure.

There are three main types of sandblasters, characterized by the difference in how the abrasive material is fed to the pressurized gun.

• Gravity-fed - This type of sand blaster relies on gravity to feed the gun. When the trigger is pulled, pressurized air immediately starts flowing through the internal structures of the device, and continues to flow as long as the trigger is held. Simultaneously, a valve is opened that allows the abrasive material to enter the chamber, where it is blown by the compressed air through the nozzle of the sand blaster.
• Pressure blaster - Commonly seen in commercial applications, this type of sand blaster combines the air and abrasive supply into a single stream. A canister of air and sand is kept under high pressure, and when the trigger on the blaster is pulled, the mixture is funneled through a specially-designed hose that can withstand the damaging effects of the high velocity pressurized abrasive.
• Siphon blaster - Most commonly used in handyman shops and home workshops, this type of sand blaster has two different hoses connected to the main body of the gun. One hose attaches to the back, and the other attaches to the bottom of the barrel. One of the hoses attaches to a supply of compressed air, and the other connects to a container of loose sand. When the trigger is pulled, the compressed air shoots out of the gun, creating a suction effect that pulls the sand out of the container and forces it out of the nozzle. This design benefits from being able to collect the used material and put it back into the container for re-use.