Wet sandblasting is a process similar to power washing. It is used to remove dirt, paint and other difficult-to-remove materials from hard surfaces, such as concrete or metal, in a process known as abrasive blasting. This process is used for industrial cleaning as well.
The process of wet sandblasting involves using abrasive mixed with water. This wet abrasive, or wet sand, is blasted out of the nozzle via air delivered by a pressurized hose and air compressor unit. Moisture will clog dry sandblasting equipment, so specialized equipment is required for this process.
In most cases, this specialized equipment is a modified pressure washer unit. Using abrasives, such as silica sand or garnet media for heavier deposits or baking soda media for industrial cleaning, these wet sandblasting units can deliver cold-water cleaning that can remove deposited debris and paint from most hard surfaces. This abrasive liquid is delivered using a kit that includes a specially designed abrasive pickup line and nozzle to mix the abrasive and water as those substances leave the sprayer unit.
The common applications for wet sandblasting include bridge work, road surfaces and curb repainting. Road crews and painters often use wet sandblasting equipment to remove paint or other substances before making repairs or repainting surfaces. In many cases, water-borne abrasives are the preferred method for this type of work because those substances do not pit the base structure in the way that dry abrasives often do.
Wet sandblasting does not create the dust and environmental hazards of dry sandblasting, so this process can be used in many places where dry sandblasting has not been a viable option. Dust and environmental dangers from airborne abrasives have made dry sandblasting dangerous for many environments. Wet sandblasting eliminates the dust and airborne contaminants, thus making it a safer option in locations where dust and contamination are unwanted.
Although the wet sandblasting process is considered to be much safer than the process of dry sandblasting, it is not without drawbacks. One of the biggest problems associated with the process is flash rust; the quick onset of a surface rust or staining with iron oxide particles on newly cleaned or sanded metals. Wet sandblasting uses moisture as part of the sanding process and thus exposes the metal to an environment where flash rust begins to set in almost immediately if the metal is not protected by a primer or sealer of some type.