C5 and C6 are used for joining ferrous materials from which they will usually receive galvanic protection in a corrosive environment. C2 and C4 are used both for ferrous materials, which will provide galvanic protection, and for copper which will cause galvanic stimulation of corrosion. Consequently, while bronze welding is generally satisfactory for copper drainage lines and for copper plumbing systems handling water with little tendency to cause dezincification, it is not suitable for copper or copper alloy sea water or brackish water lines. The note of caution concerning plumbing systems generally is because the galvanic effect of a large area of copper acting upon a small area of joint filler can cause serious damage in waters that normally cause only an acceptable degree of dezincification in brass fittings. The larger the diameter of the copper pipe the greater this effect will be.
Nickel silver is available as sheet, strip, wire, stamping, extrusions, and hot stampings.
It is also used for architectural purposes to give a warm, silvery-coloured facade, doorway or balustrade when required. The RIBA building in Portland Place, London is perhaps the prime example but many, much more recent buildings also display nickel silver used to good effect. The combination of cold working, hot working and cast forms still offers exceptional scope for architectural craftsmanship. Outdoors, treatment with very light oil, wax polish or lacquer is required to prevent eventual development of a light powdery green patina. Incralac is recommended.