Brazing fume control: respiratory hazards similar to welding

Both brazing and welding are processes for joining metals.

Welding uses very high temperatures to join like metals. Welding rod, available in a wide variety of alloys, is the gap filler.

Brazing: lower temps, flux involved

Brazing can join dissimilar metals using lower temperatures.

Typically, a flux is used to clean the joint to be brazed. The content of fluxes varies from one brazing operation to another and may include borax, zinc, and silver – even fluoride.

A braze alloy is the gap filler in brazing. The braze alloy has a lower melting temperature than the materials being joined and flows into the joint when heated.

Braze alloys are usually made up of three metals, such as aluminum, copper, and nickel. Silicon and other metals may also be used in a braze alloy.

Brazing and welding both produce hazardous fumes

Below is OSHA’s list of chemicals commonly associated with brazing and welding. Each one is linked to information about its potential health effects. For example, if you click on aluminum in the table below, you’ll see that its exposure effects can range from eye and respiratory tract irritation to pulmonary fibrosis, which is sometimes referred to as scarring of the lungs. Some studies link aluminum to dementia.

Fume capture

Sentry Air Systems designs and manufactures an extensive line of both portable and mounted fume extractors.

Our largest model [shown above], the heavy-duty, portable Model # SS-500-PFS-MP1 Floor Sentry provides respiratory fume control during brazing and welding operations.

It provides up to 1300 CFM [cubic feet per minute] of air volume and is available in a variety of source-capture configurations.

One popular option [pictured above] is an 11-foot by 8-inch diameter source-capture arm with external support, full 360º arm rotation, and an 18-gauge aluminum hood with a handle for easy adjustment.

Maintenance is simple and straightforward. The particulate filters are easily cleaned with pressurized air while the filters remain in the unit. A dust tray collects particulate for easy disposal.

The Model # SS-300-PYT [shown above] portable fume extractor’s standard magnetic source-capture hood can be repeatedly attached and re-attached to metal surfaces.

Strong magnets eliminate the need to manually hold the capture hood in place in order to contain the smoke and fumes produced by brazing and welding.

The unit’s standard 12-foot long, flame-retardant hose makes it particularly effective for hard-to-reach work locations. An optional 25-foot hose is also available.

Typical applications for this unit include fume extraction in elevated spaces and in underground confined spaces.

This unit works especially well for rapid re-location tasks that require removal of fumes, particulates and volatile organic compounds [VOC].

The wall-mounted Sky Sentry fume extractor [above] features a free-hanging, self-supportive and flame-retardant flex arm that can be maneuvered by operators.

Four models are available: SS-200-SKY, SS-300-SKY, SS-400-SKY and SS-450-SKY.

These units free up valuable benchtop and floor space. The flex arm swivels 180º and spans 62.5”.

Typical applications for this line include: welding and brazing fume extraction and containment of particulates produced by industrial processes such as grinding.

Filtration

To address applications that emit both particulates and fumes, appropriate filters can be combined within the units’ housing.

Filter options:
  • ASHRAE [up to 95% efficient on particles 0.5 microns and larger]
  • HEPA [up to 99.97% efficient on particles 0.3 microns and larger]
  • ULPA [up to 99.9995% efficient on particles 0.12 microns and larger]
  • Activated Carbon
  • Specialty-blended filtration media [i.e. Acid Gas, Mercury, Aldehyde, Ammonia]

Additional information

For further information on fume extraction options for your brazing operations, give us a call at 1.800.799.4609, email us at sales@sentryair.com, or fill out this online form to have a Sentry Air Systems Applications Specialist contact you to discuss your process.

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