Solution Summary: Needle Guns and Needle Scalers with Vacuum Dust Control
Needle guns and needle scalers with vacuum dust control safely remove lead-containing paints and coatings from surfaces.
Description:
Needle guns or needle scalers are hand-held power tools used to remove old paint, scale and rust from steel and concrete surfaces. Vacuum dust controls are available for needle guns in the form of built-in vacuum shrouds or shrouds which can be retrofitted to existing needle guns. Power tools with vacuum dust control, also known as local exhaust ventilation (LEV) reduce worker exposures during lead-based paint removal or surface preparation. Tools with LEV must be used with a portable vacuum cleaner equipped with a high-efficiency particulate air (HEPA) filter to create the exhaust.
Needle guns have a set of needles which self-adjust to the contour of work surfaces, making them suitable for use on irregular surfaces which are usually difficult to prepare such as rivet heads, corners, edges, weld seams, steel door jams, steel window sills, bridge bearings, tubing and concrete. The needles on the needle gun work by impacting the surface several hundred times per minute. Both pneumatic and electric models are available. Figure 1 shows how needle guns or needle scalers impact surfaces to remove paint or other coatings.
Aargo Inc Needle Guns with Dust Collection Attachments
|
Model # |
Cost |
Abrasive/Needle |
Length (inches) |
Blows per Minute (BPM) |
Power Source |
|
904026 |
$798 |
32 - 2mm x 7 inch hardened steel, flat tip needles |
13.5 |
4000 |
Air: 90 psi @ 9 cfm |
|
904027 |
$770 |
23 - 3mm x 7 inch hardened steel, flat tip needles |
13.5 |
4000 |
Air: 90 psi @ 9 cfm |
|
904077 |
$798 |
23 - 3mm x 7 inch hardened steel, flat tip needles |
13.5 |
4000 |
Air: 90 psi @ 9 cfm |
|
904080 |
$1970 |
32 - 2mm x 7 inch hardened steel, flat tip needles
|
20 |
3000 |
Electric: 120 Volts |
|
904003 |
$1970 |
15 - 3mm x 7 inch hardened steel, flat tip needles |
20 |
3000 |
Electric: 120 Volts |
DESCO Needleguns with Dust Collector Attachments
|
Model # |
Cost |
Abrasive/Needle |
Weight (lbs.) |
Length (inches) |
Stroke |
Power Source |
|
19 |
$548 |
19 - 3mm needles |
6.25 |
18.75 |
1 1/8” @ 4000 BPM |
Air: 90 psi @ 12 cfm |
|
20 |
$940 |
12 - 3mm or 29 - 2mm needles |
5.3 |
13.5 |
5/8” @ 4000 BPM |
Air: 90 psi @ 8 cfm |
|
24 |
$1198 |
- 53 - 2mm needles - 23 - 3mm needles - 12 - 4mm needles |
7 |
13.75 |
5/8” @ 4000 B PM |
Air: 85 psi @ 9.5 cfm |
|
25 |
$666 |
- 58 - 2mm needles - 28 - 3mm needles |
6.5 |
11.5 |
7/8” @ 3400 BPM |
Air: 90 PSI @ 3 cfm |
|
32 |
$1660 |
- 32 - 2mm needles - 15 - 3mm needles |
9.9 |
20.5 |
7/8” @ 3000 BPM |
Electric: 115 Volts; duty cycle - 30 minutes |
|
40 |
$720 |
- 58 - 2mm needles - 28 - 3mm needles |
7.9 |
11 7/8 |
7/8” @ 3400 BPM |
Air: 90 PSI @ 3 cfm |
Pentek Corner-Cutter
The Corner-Cutter is a needle gun with a variety of different attachments for scaling uneven surfaces. It is capable of scaling between 20-30 square feet per hour. It is currently priced at $4369/unit (2018) and has several different needle point options:
- 2mm diameter steel needles (flat top), best used for steel surfaces
- 3mm diameter steel needles (chisel point), best used for concrete surfaces
- 3mm diameter copper-beryllium needles (flat top), best used for reduced sparking applications in some explosive environments
- 4mm diameter steel needles (chisel point), best used for brick and other fired materials
Risks Addressed:
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 of lead dust and fumes. Construction tasks with the highest potential for exposure to lead include abrasive blasting of lead-painted surfaces, welding, and torch cutting. 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 and other personal protective equipment, 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:
A vacuum shrouded needle gun/needle scaler combines material removal and containment in a single-step operation. The shrouded needle gun removes material through the mechanical action of steel needles that chip the paint or coating, driven by pneumatic or electrical power. The vacuum shroud surrounds the needles and must be held firmly against the work surface to contain lead paint chips and dust at their source. A HEPA-filtered vacuum and hose connected to the shroud collects the lead dust safely.
Reports from the National Institute for Occupational Safety and Health (NIOSH, 1998) show that uncontrolled lead exposures from needle gun use range from 87 to 5000 μg/m3, vastly exceeding the OSHA PEL. However, a US Environmental Protection Agency (EPA) study of lead-based paint removal on highway bridges found that a needle gun system equipped with a vacuum shroud reduced the generation of hazardous waste up to 97.5% and the airborne concentrations of respirable dusts and lead-containing particulates up to 99% (Randall, Kranz, Sonntag & Stadelmaier, 1998).
Additional Considerations:
It is not advisable to use needle guns on light metal surfaces, as they will pit the surface.
Contributors:
Dhimiter Bello, Sc.D., MSc, Anila Bello, Sc.D., Vanessa Harripersaud - University of Massachusetts Lowell Department of Public Health
Bruce Lippy, Ph.D., CIH, James Platner, Ph.D, CIH, Sara Brooks, MPH, CPH - CPWR The Center for Construction Research and Training
Alan Echt, MPH, DrPH - National Institute for Occupational Safety and Health
Availability
Desco Needleguns with Dust Collector Attachments
To obtain information, visit https://www.descomfg.com/index.php/needleguns
Aargo Inc Needle Guns with Dust Collection Attachments
To obtain information, visit http://www.aargoenvironmentaltools.com/needle-guns/
Pentek Corner-Cutter®
To obtain information, visit https://www.pentekusa.com/tools/corner-cutter/
