Yes, but not cleaners that contain ammonia.
Yes, with care and the correct procedure.
Some alloys can, including copper-beryllium, copper-chromium and copper-nickel-silicon. Most unalloyed coppers and brasses can only be softened by heating.
Yes. Copper tubes do not become brittle at low temperatures. The relevant standard is ‘Seamless round tubes for air conditioning and refrigeration’, BS EN 12735: 2010 Part 1: Tubes for Piping Systems, Part 2: Tubes for Equipment.
Yes they can be brazed by all processes. Appropriate silver brazing alloys should be used as phosphorus bearing brazing alloys cause a reaction with nickel to form a brittle phosphide phase.
Yes they can using appropriate 65% nickel-copper consumables to avoid iron dilution effects.
For smaller articles, a properly applied lacquer can be used, but this may need reapplying after a number of years. A specialist company must be consulted.
For architectural objects such as statues, natural waxes can used. These will need to be reapplied every few months.
For thorough prevention, it is possible to use both lacquer and wax.
For very large areas, such as copper roofing, patination prevention is generally not practical.
BS S 369:1963 5 per cent phosphor bronze (copper-tin-phosphorus) rods and sections (other than forging stock) withdrawn and replaced by:
BS 2874:1969 Specification for copper and copper alloys. Rods and sections (other than forging stock) withdrawn because requirements were included in:
BS 2874:1986 Specification for copper and copper alloy rods and sections (other than forging stock) withdrawn and replaced by:
BS EN 12163:1998 Copper and copper alloys. Rod for general purposes and
BS EN 12164:1998 Copper and copper alloys. Rod for free machining purposes and
BS EN 12167:1998 Copper and copper alloys. Profiles and rectangular bar for general purposes
The standards in bold are current.
Yes, more copper is needed during pregnancy (1mg/day) and when breast feeding (1.3mg/day).
Yes, at least once each year.
This is an Aerospace spec. “Brass bars suitable for brazing or silver soldering 1917. It was withdrawn and replaced by BS2B11 1930 which became BS3B 1933 which was withdrawn in 1990 and not replaced. The most appropriate spec. to consult is BS EN 1044:1999 “Specifcation for filler metals for brazing.”