What is Sandblasting?
A relatively new method of cleaning newly built masonry is dry sandblast cleaning and one really needs to learn how to sandblast in order to learn all its intricacies and uses. Sandblast cleaning is used and in fact, preferred by architects as well as engineers who typically use it instead of conventional cleaning due to the fact that it does not have adverse effects, like acid reaction.
However, there are also still those, such as designers who do not favor sandblasting because they fear that blasting will erode the brick’s face as well as mortar joints.
The sandblast operator is very similar to a construction tradesman and a well qualified sandblast operator, who follows instructions properly, will enable sandblast cleaning to be superior to other systems. The basic functions that need to be understood in regards to learning how to sandblast are that it needs the use of portable air compressors, blasting tanks, blasting nozzles, operator’s protective clothing as well as hoods.
When learning how to sandblast one needs to understand that air pressure should be delivered by a compressor to the blasting tank at 40lbs. to 100lbs. per square inch. In addition, the blasting tank needs to be charged with certain abrasive material and should also be pressurized so that the mixture of abrasive material and air is forced into the blasting hose as well as to the nozzle.
Also, when learning how to sandblast, the pattern of blasting can be found by considering the size of the nozzle as well as its type and the air pressure. To find out the speed of cleaning, the type of abrasive used, size of the nozzle, its type and pressure of air as well as distance-to-wall should be considered along with the condition of the surface that needs cleaning. Mostly, sand is used as abrasive material when cleaning bricks, though quartz and granite are also used and, these should be clean and finely graded.
The cleaning material used in sandblasting should adhere to the particle size that is specified as being either Type “A” or Type “B”. Type “A” is used for masonry which is very little soiled or when light or to permit delicate texturing of the brickwork. Type “B” is used to clean heavy mortar stains from brickwork and to permit medium texturing of the masonry.
The matter of how to sandblast is best understood when one understands its reasons for use. For example, sandblast cleaning can be used to clean all hard burned, non-glazed, smooth or textured brick while lightly sanded, coated, slurry or sandbox brick is not suited for cleaning by sandblasting, unless there is no other choice open to the user.