Torch Brazing Of Aluminum Air Conditioning Assemblies

Many manufacturers are responding to corrosion concerns and fluctuating metal markets by switching the construction of evaporator coils from copper to aluminum.  Perhaps the greatest challenge in this conversion is the mastery of the brazing process.

Unlike copper, aluminum brazing alloys melt in very close proximity to the base metals. Managing this miniscule temperature window is the first and foremost challenge in brazing aluminum in open air.  A discussion of available brazing alloys is presented for the reader’s evaluation.

Aluminum brazing requires closer attention to part cleanliness.  Methods of lubricant removal are presented for evaluation.

In order for aluminum joint to be properly brazed in air, they must be fluxed.  The author discusses the use of corrosive fluxes versus non-corrosive fluxes, thermal synergy between flux and alloy options and methods of applying alloy and flux in the most cost efficient fashion.