The American Welding Society (AWS) defines soldering as taking place at temps below 800°F . Brazing is defined as taking place at temps above 800 but below the melting point of the work piece metals. The typical siver/copper brazing alloys used in gun manuf. melt at 1100 to 1500° depending on the copper content. The alloys are not affected by hot salt bluing baths, thus speeding up the manufacture of double guns.
"Cathodic protection" is the term used for protection of active metals like aluminum alloys in a salt water environment. The process uses a magnesium mass electrically connected to the aluminum and exposed to same the salt water. Magnesium is more electro-negative than the aluminum forcing the aluminum to become a cathode in the electrolytic cell formed by the two metals immersed in the electrolyte, salt water. The aluminum cathode is protected from corrosion and the magnesium anode is sacrificed instead. As long as sufficient sufficient anode area is maintained, the aluminum is protected, but the anode corrodes as long as salt water is present, so it has to be replaced periodically.
OB
