> Resource Hub  / Blog / What is water blasting, and how does it work?

In this blog, we discuss what water blasting is, its variations and how it works.

---

A variation of wet blasting is vapour blasting. In this method, pressurized air is mixed with water in the nozzle, creating a high-speed mist known as “vapour.” This technique is gentler than traditional wet blasting, enabling the cleaning of mating surfaces while preserving their compatibility.

Wet abrasive blasting uses water to propel the abrasives, offering several advantages: the water traps dust, lubricates the surface, and cushions the impact, reducing damage to sound material.

This process has its benefits over dry blasting. Wet abrasive blasting is available in various formats, including hand cabinets, walk-in booths, automated machinery, and portable units. It allows for the use of fine to coarse media with densities ranging from plastic to steel and can use hot water and soap for simultaneous degreasing and blasting. The dust reduction enhances safety when using blast media and working on asbestos, radioactive, or toxic surfaces.

Process speeds are generally slower than dry blasting with equivalent media because the water creates a lubricating cushion, protecting both the surface and the media. However, it results in reduced media breakdown, less impregnation of blasting material into the surface, dust reduction, and the elimination of static cling, producing a very clean surface.

However, wet blasting of mild steel causes immediate flash corrosion due to water presence. In some wet abrasive blasting operations, rust inhibitors or cleaning agents can be added to the slurry mixture to provide additional protection against corrosion. Moreover, using water with minimal impurities (such as distilled water) can help reduce the chance of flash rusting occurring.

Vapour blasting can be used for:

• Milder processing in comparison to other methods of blasting.
• Ideal for the treatment of mating components.
• It can be used to prepare surfaces for painting, coating, or bonding by removing old paint, rust, and other contaminants.
• It’s employed to clean tanks, pipes, heat exchangers, and other industrial equipment. It effectively removes scale, deposits, and residues without damaging the equipment.

Wet abrasive blasting can be used for:

• Blasting where dust suppression is essential, such as treating brick work or stone outdoors.
• Blasting in residential areas and locations near sensitive machinery.

• Non-toxic and eco-friendly, doesn’t involve the use of harmful chemicals.
• Suitable for a wide range of materials and applications.
• Can remove stubborn materials quickly and thoroughly.
• Being dustless, water blasting offers a safer method for removing hazardous materials and blasting outdoors where dust suppression is essential.
• It avoids static cling, resulting in a cleaner surface compared to dry blasting methods.
• Water blasting is also preferable when sandblasting would be overly destructive, as it allows for the use of softer media to protect the surface.

Water blasting can be dangerous. Operators will need thorough training to handle the equipment safely, understand the potential hazards, and respond to emergencies effectively. Issues to consider include:

• The high-pressure water jet can cause severe injuries if it comes into contact with skin or eyes. This can range from cuts and abrasions to deep lacerations and even amputations in extreme cases.
• Ensuring that debris and contaminants removed by water blasting are properly contained and disposed of is important to prevent environmental contamination and adhere to regulatory requirements.
• High-pressure water blasting equipment can be extremely loud, potentially causing hearing damage to operators and nearby personnel without proper hearing protection.
• Depending on the material being blasted, dust, and debris can become airborne, posing a risk of inhalation. This is particularly hazardous if the material contains harmful substances like asbestos, lead, or silica.
• Prolonged use of high-pressure water blasting equipment can lead to vibration-induced injuries and repetitive strain injuries.
• Water blasting creates wet and often slippery surfaces, increasing the risk of slips and falls. Adequate footwear and workplace maintenance are necessary to mitigate this risk.
• The use of water around electrical equipment poses a risk of electrocution. Proper precautions must be taken to avoid contact with electrical sources.
• Malfunctioning or poorly maintained equipment can lead to accidents. Regular inspection and maintenance of water blasting equipment are essential.

In summary, water blasting is a powerful and versatile cleaning that uses vapour/abrasive slurry to achieve a wide range of industrial and commercial tasks. Its efficiency, effectiveness, and dustless nature make it a preferred method in many applications. However, to stay safe and avoid injury, operators should wear appropriate PPE, including hearing protection, safety goggles or face shields, waterproof and cut-resistant gloves, and slip-resistant footwear, and follow implementation of safety protocols and regular safety drills to ensure all personnel are prepared for potential accidents and a safer working environment.