US Patent 7841509 Method of brazing with two different braze compositions

A copper tube with copper end pieces for a water-cooled secondary winding of a welding transformer is an example of a brazed assembly having a potentially corrodible side, the water-cooled side, and a low-exposure side, the air side or dry side, of the joined pieces. By shaping contacting surfaces of the parts at the brazed joint it is useful to form a barrier, for example, between a special braze material required for the corrosive side and a conventional, easy to apply, braze material for use on the air side of the joint.