Abstract: A volatile flux coating solution which, when dry, provides durable protective film coating containing residual flux, and a fluxing-soldering process utilizing such a solution. The coating solution is applied to a cleaned metal surface to be later joined and soldered to another metal surface, thereby obviating the need for recleaning and refluxing at the time of joining and soldering. Where two objects prepared according to this invention are joined, no additional cleaning or fluxing is required, thus saving significant time and labor at the work site. However, an object prepared according to the present invention may nevertheless be joined to an unprepared object at the work site if the unprepared object is prepared by conventional techniques, thereby allowing the prepared object to be joined with either prepared or unprepared objects. The soldering process is completed by soldering the two objects together according to conventional techniques.

Abstract: A flux coating for treating a clean metallic component having a fluid channel defined through at least a portion thereof to provide a durable, tack-free, protective flux film on a surface of the portion so that the component can be fluid-tightly soldered or low temperature brazed to a mating metallic component at a later time without cleaning and fluxing the portion of the component at the later time. The solution consisting essentially of rosin and a highly volatile organic solvent, the solution being adapted to rapidly air dry when coated on the surface of the portion to leave a very thin, protective flux film on the surface of the component, the component being capable of being stored for long periods of time, handled, assembled, shaped, formed and otherwise worked without removal of the film from the surface of the component and without reduction of the fluxing properties of the film.