Wet Abrasive Blaster

A wet abrasive blaster is an equipment used to pressure clean, texture or abrade surfaces with a blasting media mixed with water.

Description:

Using sand or alternative abrasives to clean, texture or abrade concrete, masonry materials or painted materials generates large amounts of dust which may contain high levels of crystalline silica, lead, and creates a hazard for everyone in the vicinity. Using an abrasive containing little or no silica does not eliminate the hazard when silica-containing paint, concrete or masonry is cleaned or abraded. Wet abrasive blasting is a control option for dust generated while cleaning, texturing or abrading silica-containing materials. These controls mix water and abrasive before propelling them toward the work surface and reduce airborne dust levels.

If properly designed and used, exposures can be reduced significantly.  If use is brief and intermittent, this may reduce exposures enough that a respiratory protection program isn’t required. Continuous use may exceed the OSHA Permissible Exposure Limit, however, even with the use of water.

Water Induction Nozzle (WIN®) double venturi bore nozzles

  • Used for wet or dry blasting with existing pressure blast equipment
  • Water supply: ¾ to 6 quarts per minute through a 3/4 inch hose connection
  • Sound pressure level: Not available but likely to exceed 90 dBA (OSHA’s Permissible Exposure Limit for an 8-hour time-weighted average)
Model NumberThread StyleBore Diameter, inchesAir Supply Requirement, cfmLength, inches
WIN-31-1/4 – 11-1/2 N.P.S.M.3/16455
WIN-4¼805-3/4
WIN-55/161406-1/4
WIN-63/82006-3/4
WIN-77/162558-1/4
WIN-8½3409
WIN-4502 – 4-1/2 U.N.C.¼805-3/4
WIN-5505/161406-1/4
WIN-6503/82006-3/4
WIN-7507/162558-1/4
WIN-8501/23409

cfm = cubic feet per minute

 SN BP200 Water Induction Nozzle (WIN®) double venturi bore nozzles

  • Used for wet or dry blasting with existing pressure blast equipment
  • Water supply: ¾ to 6 quarts per minute through a 3/4 inch hose connection
  • Sound pressure level: Not available but likely to exceed 90 dBA (OSHA’s Permissible Exposure Limit for an 8-hour time-weighted average)
Model NumberThread StyleBore Diameter, inchesLength, inches
SN BP200 WIN-31-1/4 – 11-1/2 N.P.S.M.¼5.75
SN BP200 WIN-55/166.25
SN BP200 WIN-63/86.74
SN BP200 WIN-77/168.27
SN BP200 WIN-81/29.05
SN BP200 WIN-4502 – 4-1/2 U.N.C.¼5.75
SN BP200 WIN-5505/166.25
SN BP200 WIN-6503/86.74
SN BP200 WIN-7507/168.27
SN BP200 WIN-8501/29.05

Mini Water Induction Nozzle (WIN®) series tungsten carbide nozzles

  • Used for wet or dry blasting with existing pressure blast equipment
  • Water supply: ¾ to 6 quarts per minute through a 3/4 inch hose connection
  • Sound pressure level: Not available but likely to exceed 90 dBA (OSHA’s Permissible Exposure Limit for an 8-hour time-weighted average)

  

Model NumberThread StyleBore Diameter, inchesLength, inches
Mini WIN-23/4-14 N.P.S.M.1/83-1/2
Mini WIN-33/16
Mini WIN-4¼
Mini WIN-55/16
Mini WIN-63/8

Torbo wet abrasive blasting systems with lower volume tanks

  • Used for a wide variety of surface cleaning and wet abrasive blasting work
  • Standard blasting media mixture: 80% blasting media / 20% water
  • Blasting hose: 1-1/4 inch
  • Sound pressure level: Not available but likely to exceed 90 dBA (OSHA’s Permissible Exposure Limit for an 8-hour time-weighted average)
ModelsCostsVolume of Vessel, cubic feetAir SupplyWater Supply, pounds per square inchBlasting Media Consumption Rate, cubic feet per hourWeight, pounds
Torbo S080Call for a quote2.670 to 175 cfm at 56 to 140 psi0 to 1700.6 to 4.51,100
Torbo M080Call for a quote2.670 to 350 cfm at 56 to 140 psi0 to 1700.6 to 4.51,100
Torbo S120Call for a quote4.270 to 175 cfm at 56 to 140 psi0 to 1700.9 to 91,100
Torbo M120$18,000 - $21,0004.270 to 350 cfm at 56 to 140 psi0 to 1700.9 to 91,100
Torbocar AC25Call for a quote2.6106 cfm at 102 psi*Onboard water tank0.6 to 4.54,400
Torbocar AC37Call for a quote4.2134 cfm at 102 psi*Onboard water tank0.9 to 94,400

cfm = cubic feet per minute

psi = pounds per square inch

*air is supplied by an onboard compressor

Torbo wet abrasive blasting systems with higher volume tanks

  • Used for a wide variety of surface cleaning and wet abrasive blasting work
  • Standard blasting media mixture: 80% blasting media / 20% water
  • Blasting hose: 1-1/4 inch
  • Blasting media consumption rate: 0.9 to 9 cubic feet per hour
  • Sound pressure level: Not available but likely to exceed 90 dBA (OSHA’s Permissible Exposure Limit for an 8-hour time-weighted average)
ModelsCostsVolume of Vessel, cubic feetAir SupplyWater Supply, pounds per square inchWeight, pounds
Torbo L200Call for a quote7.070 to 385 cfm at 56 to 140 psi0 to 1702,200
Torbo XL200Call for a quote7.070 to 385 cfm at 56 to 140 psi0 to 1702,200
Torbo L320Call for a quote11.470 to 385 cfm at 56 to 140 psi0 to 1702,200
Torbo XL320$32,000 - $34,00011.470 to 385 cfm at 56 to 140 psi0 to 1702,200
Torbocar AC52Call for a quote7.0219 cfm at 102 psi*Onboard water tank4,400
Torbocar AC76Call for a quote11.4268 cfm at 102 psi*Onboard water tank4,400

cfm = cubic feet per minute

psi = pounds per square inch

*air is supplied by an onboard compressor

Hydroblaster Abrasive Application Unit (AAU)

Used with a separate pressure washer to create a wet abrasive blasting system

Media capacity: 2.7 cubic feet

Weight: 52 pounds

Risks Addressed:

Silica dust exposure may cause silicosis or lung scarring with prolonged exposure.  Silicosis is an incurable, sometimes fatal, disease.  OSHA has a Permissible Exposure Limit (PEL) for exposure to respirable crystalline silica of 50 micrograms per cubic meter of air (µg/m3) based on an 8-hour time weighted average.  Silica has also been associated with lung cancer and chronic obstructive pulmonary disease (COPD).

Lead dust exposure can affect multiple organ systems, including the brain, heart, bones, reproductive organs, and urinary system. Lead is toxic when absorbed in the body in sufficient doses. Acute (short-term) overexposure, as short as days, may lead to a rare severe adverse health effect, acute encephalopathy, an illness affecting the brain that develops quickly into seizures, coma and death from cardiorespiratory arrest. Chronic (long-term) overexposure affects the aforementioned organ systems, especially the central nervous system (the brain). Some common symptoms of chronic overexposure include: headache, excessive tiredness, paleness (pallor), poor appetite, weakness, fine tremors, constipation, nausea, colic with severe abdominal pain, metallic taste in the mouth, nervous irritability, anxiety, hyperactivity, muscle and joint pain or soreness, insomnia, numbness, and dizziness. Lead overexposure carries risks to both the male and female reproductive systems.
 
Occupational exposure to lead comes primarily from inhalation and ingestion. Construction tasks with the highest potential for exposure to lead include abrasive blasting, welding, and torch cutting (OSHA Technical Manual, Chapter 3). Workers sometimes unintentionally bring lead dust home on their clothing, which can pose a hazard to family members. Children are especially susceptible to lead poisoning. When effective engineering controls are not available, it is important to wear protective clothing/PPE, change your clothes and shoes before getting home or entering your car, and launder all lead-contaminated clothing separately. 
 
The OSHA Permissible Exposure Limit (PEL) for lead is fifty micrograms per cubic meter of air (50 µg/m3) averaged over an 8-hour period. The voluntary NIOSH Recommended Exposure Limit (REL) and the voluntary American Conference of Governmental Industrial Hygienists (ACGIH) Threshold Limit Value (TLV) for lead also recommend maintaining exposures below 50 µg/m3, averaged over 8 hours.

How Risks are Reduced:

The abrasive media, which has traditionally been sand, is combined with water prior to leaving the nozzle. In some cases, the water is the propellant and in some cases compressed air is the propellant. When the abrasive media has been mixed with water, the fine dust and silica particles that exist in the abrasive and result from the media impacting the target material are heavier and settle to the ground before they can be inhaled. Silica and dust are only hazardous if inhaled and are not hazardous for skin contact. As long as the dust does not become airborne, the hazard is reduced. 

Other hazardous materials, such as lead in paint may also be present in dust from abrasive blasting.  Any control that reduces dust exposure will reduce exposures to all contaminants in the abrasive and in the surface being abraded.

 

Evaluations of Torbo and Boride Products wet abrasive blasting systems have demonstrated significant reductions in respirable dust and respirable silica exposure, compared to dry abrasive blasting. The studies used abrasive media containing a reduced amount of fine particulate and were therefore unable to identify the portion of the respirable silica and dust exposure reductions attributable to the use of wet methods versus fine particulate content.

Effects on Productivity:

 

Compared to abrasive blasting without water, wet abrasive blasting is expected to improve productivity by increasing visibility, reducing work site cleanup and reducing worker cleanup.
 
Wet abrasive blasting also avoids exposing other workers, members of the public, adjacent property, cars and building occupants, which can increase liability and time-consuming disputes.  Improved worker comfort is a result of reduced airborne dust which may in turn result in less fatigue for the worker and greater productivity.  In some cases, particularly where abrasive blasting is intermittent, wet methods may be adequate to reduce the need to wear a respirator and the need for an employer respiratory protection program. 
 
Some additional issues should be considered. Time may be required to allow materials to dry after wet abrasive blasting and before further work, which will depend on the material, the amount of water used and the application. The abrasive blaster needs to be located near a source of compressed air and a source of water.

Additional Considerations:

Abrasive blasting performed in the state of California must employ engineering controls, either wet methods or local exhaust ventilation, unless the employer can show that exposures are below the permissible exposure limit (subchapter 4, article 4, section 1530.1). New Jersey has a similar prohibition of dry cutting or grinding of masonry (Chapter 172).

The use of water-based controls may result in wet and slippery ground and walking surfaces. During cold weather this may lead to the formation of ice and an increased risk of slips, trips and falls. Debris and abrasive blasting media that are not removed from the work area while wet may become airborne once dried, posing an inhalation hazard to anyone in the area. Maintain a work area free of debris and excess water to reduce the risk of these hazards.
 
The use of water as a dust control increases the risk of shock when electricity is used in the same area. Electrical cords and extensions must be rated for the tool's power requirements, be regularly inspected, replaced when damaged, and used in combination with ground fault interrupt circuits.
 
The use of gasoline-powered equipment poses the risk of carbon monoxide exposure, particularly in areas where airflow is reduced. Steps to control exposure are important because the gas is invisible, odorless and tasteless. Poisoning by carbon monoxide can occur quickly indoors, but working outdoors does not ensure operators won’t be overcome. Small, inexpensive personal monitors should be worn by the operator to warn of unacceptable exposures.
 
Abrasive blasting equipment frequently generates sound levels that are greater than 90 decibels, the OSHA Permissible Exposure Limit (PEL), and hazardous. Hearing protection should be worn when performing abrasive blasting unless an industrial hygienist has conducted noise monitoring and indicated that hearing protection is not required.
 
As is the case with any construction equipment, users should follow manufacturer safety recommendations and comply with any applicable local, state or federal regulations.  When blasting lead painted surfaces or where environmental regulations requires spent abrasive be disposed of as hazardous waste for any reason, wet blasting may complicate disposal and require containment of runoff water.

Hazards Addressed:

Availability

Hydroblaster Abrasive Application Unit (AAU)
To obtain information, visit http://www.hydroblaster.com or contact 1-800-247-8424 info@hydroblaster.com

SN BP200 Water Induction Nozzle (WIN®) double venturi bore nozzles
To obtain information, visit http://www.surfaceprepsolutions.com or contact 1-800-899-3872

Torbo wet abrasive blasting systems
contact 1-817-685-7090 sales@torbousa.com

Water Induction Nozzle (WIN®) double venturi bore nozzles
To obtain information, visit http://www.surfacepreparation.com or contact 1-800-899-3872

BlastOne
To obtain information, visit The Mist Blaster or contact 1-800-999-1881

Return on Investment

To calculate the return on investment (ROI) for your specific application, please visit our Return on Investment Calculator. While a specific ROI example has not been developed for this particular solution, the ROI Calculator provides a useful tool and guidance on how to generate your own on investment analysis.