Brazing Safety
In brazing, there is always the
possibility of dangerous fumes and gases rising from base metal coatings, ink
and cadmium-bearing filler metals, and from fluorides in fluxes. The following
well-tested precautions should be followed to guard against any hazard from
these fumes.
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Ventilate confined areas. Use
ventilating fans and exhaust hoods to carry all fumes and gases away from
work, and air supplied respirators as required.
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Clean base metals thoroughly, A
surface contaminant of unknown composition on base metals may add to fume
hazard and may cause a too rapid breakdown of flux, leading to over heating.
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Use sufficient flux. Flux protects
base metals and filler metal during heating cycle. Full flux coverage reduces
fuming, Also, consult your MSDS regarding specific hazards associated with
brazing flux.
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Heat metals broadly. Heat the base
metals broadly and uniformly. Intense localized heating uses up flux,
increases danger of fuming.
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Know you base metals. A cadmium
coating on a base metal volatilize and produce toxic fume during heating. Zinc
coatings (galvanized) will also fume when heated. Learn to recognize these
coatings. It is recommended that they be removed before parts are heated for
brazing.
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Know you fill metals. Be
especially careful not to overheat assembly when using filler metals that
contain cadmium. Consult the Material Safety Data Sheet for maximum
recommended brazing temperatures of a specific filler metal. The filler metal
carries a warning label. Be sure to look for it and follow the instructions.
(For safety considerations, see the American
National Standard Z49.1, "Safety in Welding and Cutting", published be the
American Welding Society (AWS), 550 N.W. LeJeune Rd., Miami, Florida 33126.)
The above information is courtesy of Handy and Harman. If you are
looking for more information on safely working with brazing alloys and related
fluxes please contact us and we will be happy to assist you.
