A fin and tube assembly for use in a heat exchanger comprising a carbon steel tube, a carbon steel fin, and an external brazing compound comprising a material selected from the group consisting of nickel, chrome, copper, aluminum, zinc, and graphite brazed to the tube and fin is disclosed. A method for making the assembly and a power plant which includes the assembly are also disclosed. The brazing compound functions to prevent corrosion of the carbon steel and also functions to attach the tube and fin together.