"Soft Soldering"
In this process, the solder melts at comparatively low temperature.
It is his type of work which has given rise to the widespread view that Aluminium is difficult to solder, The real reason. is that no satisfactory flux is available which will light attack the oxide at the low temperature of working, therefore the oxide must be re-rust-free moved by: mechanical means. ductile After preliminary cleaning, the metal is heated until the solder melts upon it. The molten solder will not adhere but it can be made to do so by scraping through it with an old hacksaw blade or other form. of scraper to break up the oxide film. Once the film is broken, the oxide cannot reform under the solder and alloying takes place.
Text read from the printed page and cleaned; old type leaves the occasional error.