Bright Brass, Dull Brass and Antique Brass
Bright Brass,Dull Brass and Antique Brass
Brass is an alloy made of Copper and Zinc; the proportions of Zinc and Copper can be varied to create a range of brasses with varying properties. Brass has higher malleability than bronze or zinc. The relatively low melting point of brass (900 to 940 degC, 1652 to 1724 degF, depending on composition) and its flow characteristics make it a relatively easy material to cast. By varying the proportions of copper and zinc, the properties of the brass can be changed, allowing hard and soft brasses. The density of brass is approximately .303 lb/cubic inch, 8.4 to 8.73 grams per cubic centimetre. The Copper in Brass makes Brass germicidal. Depending upon the type and concentration of pathogens and the medium they are in, brass kills these microorganisms within a few minutes to hours of contact
The two main applications of Brass plating are the production of decorative deposits and a base for rubber bonding on iron and steel. For decorative plating an alloy of 60% Copper and 40% Zinc is used. 70% Copper and 30% Zinc is employed for rubber bonding. More care is required to keep alloy solution in balance than single metal deposits.
Decorative Brass Plating
Electroplated Brass is plated on ferrous metals, tinplate and Zinc base alloys.
A layer of levelling type solution, either Bright Nickel or Bright Copper, is usually applied as an initial deposit, there after a short period of Brass is electroplated so that a Bright Brass finish is obtained. The corrosion protection is provided by means of the initial electrodeposit and (if any) lacquer applied.
A Dull Brass can be produced when the nickel layer is omitted. Satin Brass is can also be produced by using Satin Nickel as the initial layer.
An Antique appearance is achieved by plating a thick layer of Dull Brass with a post plating dip into a blackening solution. Thereafter the plated item can be brushed, tumbled or polished to produce the finish of choice.