1. Raw Materials
There is a world of possibilities when designing copper interior systems, everything from panel systems that replicate what you would see
on a historical building, shingles and screens, ornaments and fixtures, and many other types of details. A few basics regarding the formats
that copper and copper alloys are available in North American will go a long way toward demonstrating that, in many cases, your imagination
is the only limit to a copper system.
Copper sheet and strip are fabricated from copper which is melted and cast into large copper cakes 10 in. thick, 40 in. wide and 40 ft. long
(about 250 mm x 1 m x 12 m). These cakes weigh about 25,000 pounds and have a purity rate of 99.5%. A cake is then rolled into the familiar sheets used in a variety of applications. In Canada architectural copper is covered by ASTM Specification B370, Copper Sheet and Strip for Building Construction. Some of the other copper alloys commonly used are covered by different ASTM standards; contact the CCBDA for
guidance on them.
The primary source for copper sheet in Canada is from mills in the U.S. with lesser amounts coming from Europe and other countries. Material
from the United States is known to be fabricated from recycled copper, where typically 95% of the copper feed material has been used in
some form before.
When other metals are added to molten copper, alloys are formed with a broad range of properties and finishes. The most recognizable alloys
are the common brasses (copper & zinc) and bronzes (copper & tin). The alloys include nickel silvers which have a silvery appearance with
a tinge of yellow.
99.9% pure copper is refined into cathode during its initial processing. On the other hand copper sheet is usually fabricated from recycled sources.
Copper is available in sheet, strip, plate and bar stock. Strip copper is material 24 in. (600 mm) wide or less. Sheet copper is material wider
than 24 in. (600 mm) with a maximum sheet width of 48 in. (1.2 m). Some larger sizes are available from suppliers overseas, although their
use is not typical in North America. The thickness of sheet and strip copper is not measured in gauges like other sheet metals but in weight as ounces per square foot. Typical weights used in architecture are 16 oz. and 20 oz.; for example one square foot of copper sheet weighs
16 or 20 ounces. Stock lengths of sheet & strip copper are 8 ft. and 10 ft (2.5 & 3.0 m). Sheet and strip copper are also available in coil form.
If the project is large enough, you can cut the copper to any length without creating a lot of scrap, which saves both time and money.
Copper plate is a much heavier product, and its thickness is not measured by weight, but in decimals of an inch.
Stock sizes of sheet and strip are shown in this table.
Copper sheet and strip are both decorative and functional. Copper and coil is often used for source material when longer pans are
Other Copper Forms
Forcing hot copper and certain copper alloys through a die creates extrusions. Many extruded shapes are possible, and some common uses
for extrusions include window & door frames, thresholds, railings and storefront systems.
Alloys such as architectural bronze and certain brasses can also be extruded. They are popular for applications where bronze and brass
colours are desired.
Copper extrusions (as shown in this picture) are available in various shapes and thicknesses and can be used for window and door frames, railings and other applications.
Copper and copper-alloy rod is also available in various diameters. It is frequently used where simple cross-sectional shapes are needed.
Copper rod is used here for a decorative light fixture.
Copper and copper-alloy tubes and pipes are available in a wide range of sizes, which can be used for applications like screening, spindles, railings and ornamental works. Tube is most commonly used, because its lighter wall thickness minimizes cost. Heavier wall pipe is not often
used, because its lighter wall thickness minimizes cost. Heavier wall pipe is not often used, but it may be considered in cases where a tubular shape needs to have certain structural strength.
Copper tube and fittings are used as a railing or a towel rack.
Copper wire and cable, mainly used for electrical applications can also form a decorative screen. Artists frequently use bare brass or
bronze wire to form delicate and intricate shaped decorative works.
Beyond various common shapes, copper alloys may be cast into a wide variety of forms. A casting is made by pouring molten metal into a
mold. Some possible applications might be a skylight frame or an elaborate handrail, as well as signage. Cast sculptures produced by the
lost wax casting process are featured in several articles in the Canadian Copper section of this web site.
A cast bronze lighting fixture.
There are also other decorative options available, such as:
- Perforated sheet (holes are punched into the metal).
- Expanded sheet copper (the metal is split and then pulled to form various sizes and shapes of openings).
- Woven copper patterns are available, and might be used as a window treatment that filters light and offers colours.