Custom Commissions from Greens Weathervanes

specialist weathervane producers

The Gallery
Woodfield Farmhouse
Tyberton, Madley
Hereford, England 01981-500-584

Copper

Periodic symbol: Cu
Atomic number: 29
Melting Point: 1083°C (1981.4°F)

Copper is prized for being non-corrosive, malleable, ductile, conductive, easy to gild, and antimicrobrial.
The most common Alloys of copper are bronze and brass. Bronze is copper mixed with tin, Brass is copper mixed with zinc. There is evidence that copper was first used 10,000 years ago.

As an example of a modern use for copper, your pc includes about 6.85 lbs of copper (with 90% said to be from recycled sources).

Repousse
Hammered Copper

Répoussé literally means "to work from behind", however, today it generally refers to both the metalsmithing techniques of embossing and chasing.

Répoussé on a Monumental Scale
The largest répoussé copper sculpture in the world is the Statue of Liberty. Given as a present to the United States from France in 1884, this symbolic monument stands from base to torch 152' 2" (46.84m) tall. The copper sheets are 3/32 inches (2.37mm) thick and are laid over a steel infrastructure.

The second largest repousse sculpture is Oregon's Portlandia, which measures 35 ft tall.

Verdigris on an antique weathervane
Verde Gris
"the green of Greece"

The green colouration (or patina) seen on bronze statues and copper roofs is called verde gris (verdigris). It is a chemical reaction copper, brass & bronze undergo when exposed to the weather (and other factors like saltwater, pollution, and situations where galvanic action occurs i.e. in contact with ferrous metals). It is not corrosive like rust (although the Italians refer to verdigris as "noble rust"). It is considered poisonous, and has been used both as a fungicide and a medicine. This hallmark powdery green patina is highly prized by collectors and difficult to achieve successfully with chemical substitutes.

The following gives a general timeline for the beginnings of a light green patina:

7-9 years in saline climates (i.e. near the coast)
5-8 years near heavy industry
10-14 years in urban areas
30 years or more in a clean environment

Gold

Periodic symbol: Au
Atomic number: 79
Melting Point: 1064.43°C

Gold Leaf
1.27x10^-5cm thick

Although ornaments wrought in gold have been dated from 4,000BC, the Egyptians were the first gilders. Thin sheets of of gold were created by beating them with round stones, Modern techniques for creating gold leaf have remained largely unchanged from this 1200BC Egyptian process, aside from the introduction of metal hammers.

Greens Weathervanes use 23.5 K double thick English Gold Leaf. The sheets of loose leaf gold are applied to the copper's surface using a squirrel hair gilder's tip. The copper's surface is first prepared by cleaning, priming, and sizing using a 12 hour oil-based size. It is the sizing which, when tacky bonds the gold to the copper. Finally the gold is burnished.

The manufacturer recommends regilding after 20-30 years.

The Copper Development Agency's website serves as an invaluable educational resource for those interested in copper. They have kindly allowed the following link:

Copper Weathering Chart

(This is an 3.61 MB pdf document and will take a few minutes to download)

click on this link for a
history of copper

•the UK Copper Development Agency's website www.cda.org.uk
•www.copperconcept.org gives some inspiring examples of modern applications for copper in architecture

Greens use only the finest quality .5mm (16 ounce) copper available in England. All work is brazed rather than lead soldered for strength. Brass and bronze fittings are standard and only 23½K double thick English gold leaf is applied. No lacquers or fake patinas are used. A 3/4 inch solid bronze bearing is incorporated into the body of every weathervane. Marine grade stainless steel is provided.

Copper Mining in the UK
Wheal Betsey copper mine

Historically, Britain has played a central role in copper production since pre-Roman times, becoming the world's 4th largest copper producer during much of the 19th century. Today there are no active copper mines in Britain; however the evidence of copper mining, in SW England and NW Wales, can be dated as far back as the Bronze Age. Notably, trade in copper and tin was carried out between Britain (Cornwall) and the Phoenicians as early as 1500 BC, with Britain, at the time, referred to as the 'Cassiterides' -the 'Tin Islands'.

the largest copper mine in the world today is in Chile.

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