applications range from:

• plumbing
• tap and faucet fittings
• decorative domestic fixtures
• large heavy industrial uses
• electrical components from sockets and contacts
• highly complex electrical switchgear
• general engineering
• cold formed brass screws
• machined components requiring precision tolerances

Architectural applications;

• precision engineered doors and window suites
• handrails and balustrades (as seen in many major building projects around the world)
• sports and recreation (some at the world’s favorite fishing lures

General Information

DEFINITION

In its basic form Brass is an alloy of copper and zinc, but most alloys contain additional elements. For architectural purposes Brasses are widely used, however the building industry commonly refers to some of these alloys as Bronze; although it is a misnomer, it is accepted practice.

In its basic form Bronze is an alloy of copper and tin. Within architectural applications true bronze is rarely used.

In its basic form Nickel Silver is an alloy of copper, nickel and zinc, which has a warm silver appearance.

USES

JOINING

(i) Screws, belts, rivets.

(ii) Extensions can be custom designed to incorporate a snap’ or ‘slide’ fit to loin various shapes (for example see Shape Nos. 3626, 3711, 3685 & 3683 on Page 50).

Sheets laminating to steel, plywood or similar substrate. (See also Dissimilar Metals). Brass and Bronze can also be adhered to itself if intersecting members are mechanically aligned, for example with a sleeve and locking pins.

(i) Brazing

A medium temperature joining method involving the melting of the filler material without melting the base material. Because color matching of brazed fillers is difficult, brazing is best done with blind or concealed joints. Brazing is the preferred metallurgical joining method as it does not distort the base material.

(ii) Soldering

A low temperature joining method used for sealing joints which does not result in a strong bend and is therefore best used in conjunction with mechanical fasteners.

(iii) Welding

A high temperature joining method which fuses base materials, but is generally not used for architectural work because of color matching and joint distortion problems.

DISSIMILAR METALS

MECHANICAL SURFACE TREATMENTS

The finishes imparted by normal production of extrusions, forgings. castings, etc.

(b) BUFFED

A process of grinding, polishing and buffing. Finishes range from low luster polish to smooth mirror finish.

(c) DIRECTIONAL TEXTURED

The most common finish on architectural shapes. This finish is produced by polishing of the surface with near parallel lines, resulting in a smooth, velvety appearance often referred to as ‘satin finish’.

(d) NON-DIRECTIONAL TEXTURED

Matte finishes of varying degrees of abrasion.

(e) PATTERNED

A combination of textural finishes, often referred to as embossing’ or ‘coining’.

COLOR

(a) GENERAL

The characteristic colors of Architectural Brass, Bronze and Nickel Silver in their As-Manufactured, Polished and Chemically Colored states are tabulated on page 31.

Most Brass and Bronze alloys have a GOLDEN HONEY color in their natural state and a RICH STATUARY BRONZE in their chemically colored state. Brasses which contain aluminum exhibit a BRIGHT YELLOW coloring in their as-manufactured state, but the color changes to HONEY when polished. PINK Brass and Nickel Silver are also available when alternative coloring is required.

(b) NATURAL COLOR

Natural honey colored Brass & Bronze is as the name suggests, however the difficulty with it lies in the tact that, given enough time, it will weather to a brown color. Obviously, this occurs more rapidly when it is exposed to weather. The rate of weathering depends on the degree of humidity, and the level of pollutants in the air. A greater problem occurs with fingerprints. Acids from the body leave marks on the natural Brass & Bronze, and for this reason natural honey Brass & Bronze needs to be protected, either by coating, or by cleaning and/or polishing regularly if it is handled constantly, as in the case of handrails and door furniture.

Chemical coloring is a process with great dependence on the experience of the craftsman. In general, all types of chemical coloring artificially weather the Brass or Bronze from its natural color to a darker color. This is accomplished by converting the surface of the metal into a colored protective film, using an oxide or a sulfide.

For architectural use, chemical coloring is used to achieve a ‘statuary’ finish (i.e. a medium to dark brown appearance) through either of two methods. The first method is to dip the material in a chemical bath and is practical for small pieces. The second method is to brush on and wipe of f one of the several available chemicals. This is more appropriate for larger pieces and can be performed in the factory or in situ.

It is sometimes impractical, costly and unnecessary to have a finisher handle every piece of Brass or Bronze, however the talents of a craftsman should be used when:

The Brass or Bronze piece in question cannot be readily immersed in a chemical bath.

(ti) Precise color matching of separate pieces is made necessary by immediate adjacency.

(iii) The surface area of Brass & Bronze pieces is sufficient to require an even-handed wrought appearance

(iv) Special circumstances of manufacture and/or delivery of Brass & Bronze makes hand-finishing the only choice.

Examples of fittings which may require hand coloring are:

(i) Status Door Pulls

(ii) Special Extrusion Doors and Frames

(iii) Lift Entrances and Cabs

(iv) Timber/Bronze Doors

Chemically colored Brass & Bronze should be maintained and protected by the repeated application of oil or wax (linseed, lemon and paraffin oils are commonly used). The frequency of oiling will decrease over time as layers of oil build up to create a protective surface and result in what is known as oil rubbed bronze’.

When a piece of oil rubbed Brass or Bronze is repeatedly touched, as with door knobs, the oil and colored surface wear through to the natural base color.

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