Hilco Bronze Flux is suitable for use on copper, brass, mild steel and most other common materials. Bronze Flux is available in powder only. This powder can be made into a paste by stirring in water until the mixture has the consistency of thick cream. The flux can be applied by hot prodding i.e. dipping a warm rod into flux powder and the flux adhering to the rod is transferred to the joint area.
A molten brazing alloy will only wet and flow over a parent metal if both are substantially free of surface oxide. Simply removing surface oxide before brazing is not effective since a new oxide layer is rapidly formed on heating. To achieve a oxide-free surface it is necessary to:
• Remove oxide as it is formed using a suitable brazing flux, or
• Prevent oxidation during brazing by heating in a protective atmosphere, or
• Use a self-fluxing brazing alloy (possible when copper-to-copper brazing only!)
