Cover
Preface
CHAPTER 1: Introduction—Element 29
1. INTRODUCTION
2. COLOR
3. COLORS OF ALLOYS
4. COPPER MINERALS
5. HISTORY
6. THE MODERN COPPER PRODUCTION PROCESS
7. SUSTAINABILITY, ENVIRONMENTAL, AND HYGIENIC CONCERNS
8. COPPER AND WATER
9. HEALTH AND SAFETY
10. COPPER: THE ANTIMICROBIAL METAL
11. COPPER ALLOYS FOR THE ARTS
12. NOTES
CHAPTER 2: Copper and Its Alloys
1. INTRODUCTION
2. THE RICH HISTORY OF COPPER ALLOYS
3. ELEMENTS ADDED TO COPPER
4. ALLOY DESIGNATION SYSTEM
5. THE UNIFIED NUMBERING SYSTEM
6. TEMPERS
7. WROUGHT COPPER ALLOYS
8. BRASSES
9. LEADED BRASSES
10. TIN BRASSES
11. PHOSPHOR–BRONZE ALLOYS
12. ALUMINUM–BRONZE ALLOYS
13. SILICON–BRONZE ALLOYS
14. COPPER–NICKEL AND NICKEL–SILVER ALLOYS
15. CAST ALLOYS
16. RED BRASSES
17. YELLOW BRASSES
18. SILICON–BRONZE ALLOYS
19. A TIN–BRONZE ALLOY
20. NICKEL–SILVER ALLOYS
21. A MANGANESE–BRONZE ALLOY
22. NOTES
CHAPTER 3: Surface Finishes
1. INTRODUCTION
2. MILL SURFACES
3. MECHANICAL FINISHES AND TEMPORARY PROTECTION
4. COLOR FROM OXIDATION AND CHEMICAL REACTIONS
5. TEXTURES
6. TIN‐COATED COPPER
7. MELTED COPPER ALLOY SURFACING
8. COPPER AND GLASS
9. PROTECTING THE SURFACE
10. NOTES
CHAPTER 4: Expectations of the Visual Surface
1. INTRODUCTION
2. INTENT: AN UNCHANGED SURFACE APPEARANCE
3. INTENT: A SURFACE APPEARANCE THAT CHANGES NATURALLY
4. FLATNESS
5. TEXTURING THE SURFACE
6. INITIAL OXIDATION ON COPPER ALLOYS
7. IN SITU PATINATION
8. PREPATINATION
9. THE EFFECT OF SEALANTS
10. THE CAST SURFACE
11. ARRIVING AT THE BEST POSSIBLE OUTCOME
12. NOTES
CHAPTER 5: Designing with the Available Forms
1. A BRIEF HISTORY
2. WROUGHT FORMS
3. THE CAST FORM
4. NOTES
CHAPTER 6: Fabrication Processes and Techniques
1. INTRODUCTION
2. FORMING
3. V‐CUTTING
4. CUTTING COPPER ALLOYS
5. MACHINING
6. SOLDERING, BRAZING, AND WELDING
7. CASTING
CHAPTER 7: Corrosion Characteristics
1. GENERAL INFORMATION
2. CATEGORIES OF CORROSION
3. ENVIRONMENTAL EXPOSURES
4. ACIDS AND BASES
5. COPPER ALLOY SURFACE CATEGORIES
6. NOTES
CHAPTER 8: Maintaining the Copper Alloy Surface
1. INTRODUCTION
2. PROTECTING THE NEW COPPER ALLOY SURFACE
3. ACHIEVING PHYSICAL CLEANLINESS
4. ACHIEVING CHEMICAL CLEANLINESS
5. ACHIEVING MECHANICAL CLEANLINESS
6. REPAIRING PATINAS
7. PROTECTING THE SURFACES OF COPPER AND COPPER ALLOYS
8. CLEANING THE COPPER SURFACE
9. REMOVING COPPER STAINS FROM OTHER SUBSTANCES
10. DETERIORATING PATINAS
11. NOTES
APPENDIX A: Comparative Attributes of Metals Used in Art and Architecture
APPENDIX B: Hardware Finish Codes and Descriptions
APPENDIX C: Numbering Systems Used for Copper Alloys
Further Reading
Index
End User License Agreement

List of Tables

Chapter 1
1. TABLE 1.1 Electrical conductivity of various metals in siemens m⁻¹ at 20 °...
2. TABLE 1.2 Approximate percentages of elements in the Earth's upper mineral strat...
3. TABLE 1.3 Mineral forms of copper.
Chapter 2
1. TABLE 2.1 A few of the names given to alloys of copper.
2. TABLE 2.2 UNS number ranges for wrought copper alloys.
3. TABLE 2.3 UNS number ranges for cast copper alloys.
4. TABLE 2.4 A few common cold rolled wrought temper designations.
5. TABLE 2.5 A few common hot rolled temper designations.
6. TABLE 2.6 A few common temper designations of copper.
7. TABLE 2.7 True brasses.
8. TABLE 2.8 List of leaded copper–zinc alloys.
9. TABLE 2.9 List of nickel–silver alloys used in architecture.
10. TABLE 2.10 Common cast tempers.
11. TABLE 2.11 Common cast alloys.
Chapter 3
1. TABLE 3.1 Scotch‐Brite pad color and corresponding grit range produced.
2. TABLE 3.2 Buffing compounds used on copper alloys.
3. TABLE 3.3 Colors achieved using certain chemical compounds.
Chapter 4
1. TABLE 4.1 Coating comparisons.
2. TABLE 4.2 Coefficient of linear expansion of various copper alloys.
Chapter 5
1. TABLE 5.1 Comparison of alloying constituents of Muntz Metal with Architectural ...
2. TABLE 5.2 Approximate weights for copper sheet and plate.
3. TABLE 5.3 Typical widths available for plate.
4. TABLE 5.4 Standard lengths of sheets.
5. TABLE 5.5 Typical widths available for sheet stock.
6. TABLE 5.6 Correlation of weight thickness to nominal length thickness.
7. TABLE 5.7 Nominal foil thicknesses and unit weights.
8. TABLE 5.8 Several extrudable copper alloys.
9. TABLE 5.9 Several of the copper alloys available in wire form.
10. TABLE 5.10 Various strand configurations.
11. TABLE 5.11 Comparisons of casting methods used on copper alloys.
12. TABLE 5.12 Factors to consider for various cast methods.
Chapter 6
1. TABLE 6.1 Cutting methods used on copper alloys.
2. TABLE 6.2 Machineability of copper alloys.
3. TABLE 6.3 Leaded solders.
4. TABLE 6.4 Lead‐free solders.
5. TABLE 6.5 Common brazing alloys.
6. TABLE 6.6 Welding processes used on copper alloys.
7. TABLE 6.7 Various surface maladies seen on castings.
8. TABLE 6.8 Elongation of C11000 by temper designation.
Chapter 7
1. TABLE 7.1 Common mineral forms of copper.
2. TABLE 7.2 Various mineral forms of copper.
3. TABLE 7.3 Corrosion categories.
4. TABLE 7.4 Oxides of copper.
5. TABLE 7.5 A few of the minerals and associated colors of the patinas.
6. TABLE 7.6 Electrical potential of various metals in flowing seawater.
7. TABLE 7.7 ISO environmental exposure categories.
Chapter 8
1. TABLE 8.1 Levels in achieving physical cleanliness.
2. TABLE 8.2 Chemically clean surface levels for copper alloys.
3. TABLE 8.3 Relative hardness of substances on the Moh scale.

List of Illustrations

Chapter 1
1. FIGURE 1.1 Copper's position in the periodic table of elements.
2. FIGURE 1.2 Face‐centered cubic structure of a copper crystal.
3. FIGURE 1.3 Copper atom.
4. FIGURE 1.4 Sea of shared electrons around the metal atoms of copper.
5. FIGURE 1.5 Reflectivity of aluminum, silver, stainless steel, copper, and gold...
6. FIGURE 1.6 Image of different alloys and colors.
7. FIGURE 1.7 Color changes in brass alloys.
8. FIGURE 1.8 A naturally formed patina.
9. FIGURE 1.9 The Statue of Liberty.
10. FIGURE 1.10 Perseus with the Head of Medusa, by Benvenuto Cellini.
11. FIGURE 1.11 Various minerals of copper.
12. FIGURE 1.12 Approximate time periods of major copper activity in ancient times...
13. FIGURE 1.13 Image of the Ontonagon copper boulder.
14. FIGURE 1.14 Roman helmets made from copper.
15. FIGURE 1.15 Giant cast Buddha at the Todaiji Temple in Japan.
16. FIGURE 1.16 Image of religious totemic items.
17. FIGURE 1.17 Bronze cannon.
18. FIGURE 1.18 Initial mill forms.
19. FIGURE 1.19 Examples of special‐order copper alloys with biocide properties fr...
20. FIGURE 1.20 Cast dragon ornamentation on the Town Hall in Munich, Germany.
21. FIGURE 1.21 A repoussé copper piece from Jerusalem.
22. FIGURE 1.22 Heartland Harvest, Kansas City Board of Trade.
23. FIGURE 1.23 Copper spot price in US dollars per pound over a 30‐year period.
Chapter 2
1. FIGURE 2.1 Copper handrail and copper wire rope.
2. FIGURE 2.2 Panel system made of the C11000 alloy at the de Young museum in San...
3. FIGURE 2.3 Copper alloy C22000 in the Ohio Holocaust and Liberators Memorial,
4. FIGURE 2.4 Mirror polished C26000 alloy.
5. FIGURE 2.5 Polished C28000 alloy entryway.
6. FIGURE 2.6 Alloy C37700 was used on the artwork for the Museum of the Bible.
7. FIGURE 2.7 Extruded plates of alloy C38500 (Architectural Bronze) used for the...
8. FIGURE 2.8 Alloy C61000 form made from thin sheet.
9. FIGURE 2.9 Interior walls made of alloy C75200.
10. FIGURE 2.10 Art cutout using alloy C75200.
11. FIGURE 2.11 The use of alloy C83600 for the cast doors at the Kansas City Life...
Chapter 3
1. FIGURE 3.1 Heavy oxidation on a thick copper alloy plate.
2. FIGURE 3.2 Art deco nickel silver.
3. FIGURE 3.3 The aluminum–bronze alloy TECU Gold, produced by KME of Germany, wa...
4. FIGURE 3.4 Alloy C28000, polished and coated with clear Incralac, in use at th...
5. FIGURE 3.5 The de Young museum, 1.5‐millimeter‐thick copper sheets made into I...
6. FIGURE 3.6 Kiosk at the Midland Theatre, Kansas City, Missouri.
7. FIGURE 3.7 Comparison of the natural color of various alloys of copper.
8. FIGURE 3.8 A large cone of the naturally colored C22000 alloy with an Angel Ha...
9. FIGURE 3.9 Curved custom polished surface using the C22000 alloy.
10. FIGURE 3.10 A C11000 surface with in‐and‐out embossed bumps in a Prada store.
11. FIGURE 3.11 Heat‐generated color on copper alloy C11000.
12. FIGURE 3.12 Niello used on a bronze axe head and a helmet.
13. FIGURE 3.13 Ohio Holocaust and Liberators Memorial, Columbus, Ohio,
14. FIGURE 3.14 Custom doors made of the C22000 and C28000 brass alloys.
15. FIGURE 3.15 Bond Street window surrounds made of the C11000 alloy,
16. FIGURE 3.16 Left: Addition to the Walker Art Building at Bowdoin College in Br...
17. FIGURE 3.17 Various Dirty Penny tones.
18. FIGURE 3.18 Dirty Penny on copper panels made of the alloy C11000 after three ...
19. FIGURE 3.19 Perforated and bumped Dirty Penny copper alloy C11000.
20. FIGURE 3.20 Fifty‐millimeter thick black copper plate by John Labja.
21. FIGURE 3.21 Robert Hoag Rawlings Public Library, Antoine Predock Architect.
22. FIGURE 3.22 Blackened copper alloys in three projects.
23. FIGURE 3.23 Three examples of red patinas.
24. FIGURE 3.24 Red patina on panels at the Daeyang Gallery and House, Korea,
25. FIGURE 3.25 The patinated copper roof dating to 1625 on Børsen and t...
26. FIGURE 3.26 Walls clad in prepatinated copper.
27. FIGURE 3.27 Patinated walls right after installation and several years later.
28. FIGURE 3.28 Roof and soffit surfaces in Hong Kong.
29. FIGURE 3.29 Various patinas that can enhance copper alloys.
30. FIGURE 3.30 Various artworks made of patinated copper.
31. FIGURE 3.31 Formation of patina.
32. FIGURE 3.32 Layering of patinas for the art wall in the Smithsonian's National...
33. FIGURE 3.33 Custom patination across multiple panel elements.
34. FIGURE 3.34 Cold patina blend over a surface.
35. FIGURE 3.35 Price Tower, Bartlesville, Oklahoma, designed by Frank Lloyd Wrigh...
36. FIGURE 3.36 Heartland Harvest, Kansas City Board of Trade,
37. FIGURE 3.37 Green patina on Muse of the Missouri by Wheeler Williams (1963).
38. FIGURE 3.38 Left: Gold patina cast doorRight: Black...
39. FIGURE 3.39 Two Piece Mirror Knife Edge by Henry Moore, East Building, Nationa...
40. FIGURE 3.40 French brown patina on cast pillar with bas relief, by Manuel Carb...
41. FIGURE 3.41 Repoussé and chasing work on ornamental panels.
42. FIGURE 3.42 Hammered copper surface used on a kitchen hood in a residence.
43. FIGURE 3.43 Deep hammering of copper surfaces.
44. FIGURE 3.44 Embossed copper.
45. FIGURE 3.45 Custom patterns pressed into thin sheet copper.
46. FIGURE 3.46 Tactile surface textures produced using CNC.
47. FIGURE 3.47 Copper wall reflecting off the glass in the fern court at the de Y...
48. FIGURE 3.48 Etched and darkened C26000 alloy.
49. FIGURE 3.49 Various examples of etched and engraved copper alloys.
50. FIGURE 3.50 Chemical milled C22000 plate below.
51. FIGURE 3.51 Top: Laser‐etched names in Commercial Bronze (alloy C22000). Lower...
52. FIGURE 3.52 Left: Silver plate on copper demonstration sample. Right: Chrome p...
53. FIGURE 3.53 Top: Chrome‐plated Fuga, by Jan Hendrix. Lower left: Nickel plate ...
54. FIGURE 3.54 Tin‐coated copper.
55. FIGURE 3.55 Melted copper alloy surfaces.
56. FIGURE 3.56 Copper and glass.
Chapter 4
1. FIGURE 4.1 Newly installed copper on a roof in Minnesota and on walls in Texas...
2. FIGURE 4.2 Cuprous oxide forming on the C11000 panels used at the de Young mus...
3. FIGURE 4.3 Interference oxides developing on copper surfaces exposed to the at...
4. FIGURE 4.4 Distinct design paths for the use of copper alloys in art and archi...
5. FIGURE 4.5 Benzotriazole test.
6. FIGURE 4.6 Fireman's Memorial fountain sculpture. Designed by artist Tom Corbi...
7. FIGURE 4.7 Sketch of Incralac lacquer and a wax coating on a copper alloy.
8. FIGURE 4.8 Old wax showing signs of decay.
9. FIGURE 4.9 The Muse of Missouri and stains developing on its patina.
10. FIGURE 4.10 Copper alloy handrails showing signs of patina wear from human int...
11. FIGURE 4.11 Benzotriazole bond with surface copper.
12. FIGURE 4.12 Left: Heartland Harvest, an artwork using the C11000 alloy at the ...
13. FIGURE 4.13 Bottom: Differences in metal color tone below the clear film when ...
14. FIGURE 4.14 Newly installed thin copper sheathing.
15. FIGURE 4.15 Flat‐seam thin copper panels and expected direction of geometry ch...
16. FIGURE 4.16 Sheet width‐to‐thickness relationship to ensure flatness.
17. FIGURE 4.17 Examples of embossed copper sheet.
18. FIGURE 4.18 Cupric oxide forming on the surface of copper shortly after instal...
19. FIGURE 4.19 Cupric oxide changing with time of exposure.
20. FIGURE 4.20 Failure of in situ patination.
21. FIGURE 4.21 Left: Prepatina on interior walls at the University of Toronto. Ri...
22. FIGURE 4.22 Sealant streaking below glazing.
23. FIGURE 4.23 Marks from a marking pen on a metal after 25 years of exposure.
24. FIGURE 4.24 Copper roof surface. Top: Initial installation. Bottom: After two ...
25. FIGURE 4.25 The surface of the National Underground Railroad Freedom Center de...
Chapter 5
1. FIGURE 5.1 Left: Ancient formed spear; top right: ewer; bottom right: helmet m...
2. FIGURE 5.2 Etched cross‐section of an initial casting of copper.
3. FIGURE 5.3 Large slab of copper at the rolling Mill.
4. FIGURE 5.4 Large copper coils.
5. FIGURE 5.5 Thick copper plate.
6. FIGURE 5.6 Copper panels on the de Young museum in San Francisco.
7. FIGURE 5.7 Various copper roof types. Top left: batten seam; top right: standi...
8. FIGURE 5.8 Copper leafing.
9. FIGURE 5.9 An extrusion must fit within a circle whose size is determined by f...
10. FIGURE 5.10 (a–c) Examples of hollow, semihollow, and solid extrusions.
11. FIGURE 5.11 A box extrusion made from two sections that snap together.
12. FIGURE 5.12 Improvements to extrusion design to aid in metal flow.
13. FIGURE 5.13 A larger part created from a series of smaller extrusions.
14. FIGURE 5.14 Extruded brass with statuary finish on the Ohio State Supreme Cour...
15. FIGURE 5.15 Entertainment Building, Hong Kong.
16. FIGURE 5.16 Copper bar used as handrails at the Smithsonian's National Museum ...
17. FIGURE 5.17 Examples of different sized bars and rods used in art applications...
18. FIGURE 5.18 Copper wire rope used as an artistic feature on the handrails at t...
19. FIGURE 5.19 Three examples of expanded copper alloy.
20. FIGURE 5.20 Expanded patinated copper surface created from KME's TECU Patina M...
21. FIGURE 5.21 Fine mesh light diffuser.
22. FIGURE 5.22 Decorative copper alloy meshes.
23. FIGURE 5.23 Custom perforation of the C11000 alloy used in the Irving Conventi...
24. FIGURE 5.24 The C11000 alloy with a Dirty Penny finish, surfaced with bumps an...
25. FIGURE 5.25 Sand cast door handles made from silicon–bronze alloy C87300.
26. FIGURE 5.26 Cross‐section of a typical sand cast mold.
27. FIGURE 5.27 Throwing in the Towel
Chapter 6
1. FIGURE 6.1 Stress–strain graph of copper.
2. FIGURE 6.2 Hammered copper vase.
3. FIGURE 6.3 Ancient Roman helmet hammered out of copper alloy.
4. FIGURE 6.4 Various fabricated copper items.
5. FIGURE 6.5 Bending with and against the grain.
6. FIGURE 6.6 V‐cutting copper alloys.
7. FIGURE 6.7 V‐cut corner on panels at the de Young museum of art.
8. FIGURE 6.8 Shaping copper alloys.
9. FIGURE 6.9 Graph of change in yield strength as alloying elements are added.
10. FIGURE 6.10 Copper and copper alloy–clad surfaces.
11. FIGURE 6.11 Left: Decorative leaf form by Reilly Hoffman. Right: Decorative gr...
12. FIGURE 6.12 Waterjet cut thick brass inserts.
13. FIGURE 6.13 Gate with waterjet cut angels.
14. FIGURE 6.14 Laser cutting in Fuga
15. FIGURE 6.15 Laser cut artwork
16. FIGURE 6.16 The plasma cut copper artwork Hands of Man by the author.
17. FIGURE 6.17 Machined copper alloy parts.
18. FIGURE 6.18 Machining, texturing, and finishing of panels at the Museum of the...
19. FIGURE 6.19 Top: Initial mill marks on the metal surface. Bottom: Computer ima...
20. FIGURE 6.20 Machined lettering at the Museum of the Bible, designed by Larry K...
21. FIGURE 6.21 Soldered joints in a copper roof.
22. FIGURE 6.22 Left: Brazed copper with blown glass. Right: Brazed copper wire an...
23. FIGURE 6.23 Two solder joints on thin sheet material.
24. FIGURE 6.24 Left: Welding of C22000 plates. Right: Welding of a handrail using...
25. FIGURE 6.25 Welding of a copper elbow for the Prada store in Tokyo.
26. FIGURE 6.26 Visible welds on weathered cast bronze.
27. FIGURE 6.27 Various examples of sand‐cast shapes, from simple to intricate.
28. FIGURE 6.28 Spun and polished copper hemisphere light sconce.
29. FIGURE 6.29 Plastic deformation zone before fracturing.
30. FIGURE 6.30 Custom perforating and embossing.
31. FIGURE 6.31 Custom embossed copper at the de Young museum of art
32. FIGURE 6.32 Roll embossed finish: (top) unaged surface; (bottom) a finish expo...
33. FIGURE 6.33 Diagram showing hold‐down clearance needed for custom embossing.
Chapter 7
1. FIGURE 7.1 Christ Church in Philadelphia, Pennsylvania, has the oldest copper ...
2. FIGURE 7.2 Top: Hildesheim Cathedral has the oldest existing copper roof in Eu...
3. FIGURE 7.3 Statue of Liberty.
4. FIGURE 7.4 Cuprous oxide on a door made of copper plate.
5. FIGURE 7.5 Black cupric oxide formation on copper exposed to low pH and humidi...
6. FIGURE 7.6 Weathered copper alloy doors showing the presence of both oxides.
7. FIGURE 7.7 Casting made of the C87610 alloy near the seaside.
8. FIGURE 7.8 Prepatinated surface in Corpus Christi, Texas.
9. FIGURE 7.9 Polished Cartridge Brass (alloy C26000) showing tarnish from handli...
10. FIGURE 7.10 Green developing along the lower edge of a copper panel.
11. FIGURE 7.11 Makeup of a galvanic cell.
12. FIGURE 7.12 An idealized cold‐water connection where a copper pipe is joined t...
13. FIGURE 7.13 Stainless steel supports and the C22000 copper alloy in a chloride...
14. FIGURE 7.14 The galvanic circuit and the means to prevent it from occurring.
15. FIGURE 7.15 Dezincification on a C26000 surface.
16. FIGURE 7.16 Microscopic images of dezincification corrosion.
17. FIGURE 7.17 Fingerprints and handprints on different surfaces.
18. FIGURE 7.18 Cleaning compounds left on the surface.
19. FIGURE 7.19 Corroding steel support under a cast copper alloy handrail cap.
20. FIGURE 7.20 Relationship of metal temperature to ambient air temperature.
21. FIGURE 7.21 One‐hundred‐year‐old copper and brass time capsule.
22. FIGURE 7.22 Copper panels affected by moisture entering a crate.
23. FIGURE 7.23 Streaks on the upper regions of a sculpture.
24. FIGURE 7.24 The chlorides in deicing salts will affect copper surfaces.
25. FIGURE 7.25 Uncoated copper roof and walls.
26. FIGURE 7.26 Copper alloy art inserted in the terrazzo floor of Miami Internati...
27. FIGURE 7.27 (Left) Patinated copper art, (middle) roofs, and (right) walls.
28. FIGURE 7.28 Prepatinated copper surfaces: (top) successful and (bottom) unsucc...
29. FIGURE 7.29 Unprotected patinas on bronze.
30. FIGURE 7.30 Under‐film oxidation on brass.
Chapter 8
1. FIGURE 8.1 Tarnish on copper surface of a door made from thick copper plates.
2. FIGURE 8.2 Cleaning solution and handprint left on a copper alloy form.
3. FIGURE 8.3 Fingerprints on copper alloy surfaces.
4. FIGURE 8.4 Panels at the 9/11 Memorial darkening under the film.
5. FIGURE 8.5 Image of test results of ability of benzotriazole to prevent tarnis...
6. FIGURE 8.6 Bird waste on copper wall panels and a bronze sculpture.
7. FIGURE 8.7 Bird waste beginning to interact with the copper alloy used for
8. FIGURE 8.8 (Left) Bird waste, (top right) old wax, and (bottom right) Mill pri...
9. FIGURE 8.9 Deicing salt residue on surfaces.
10. FIGURE 8.10 Deicing salt damage to copper surfaces.
11. FIGURE 8.11 (Left) Old wax and (right) renewed wax on a bronze sculpture by th...
12. FIGURE 8.12 Muse of Missouri by Wheeler Williams.
13. FIGURE 8.13 Microscopic image of the decaying coating.
14. FIGURE 8.14 Rust stains on the Muse sculpture from deposits in the water.
15. FIGURE 8.15 Cleaning copper alloy surfaces with mild soap and water.
16. FIGURE 8.16 (Right) Cleaning fluid left on a surface, (top left) iron rust sta...
17. FIGURE 8.17 Dark streaks of cupric oxide visible on old copper surfaces.
18. FIGURE 8.18 Cast copper alloy doors after decades of exposure.
19. FIGURE 8.19 Initial removal of oxides.
20. FIGURE 8.20 Much of the tarnish, old oxide, and patina was removed from the su...
21. FIGURE 8.21 Developing the statuary finish.
22. FIGURE 8.22 The restored doors are hung.
23. FIGURE 8.23 (Left) Removing oxides from C26000 alloy and (right) repolishing t...
24. FIGURE 8.24 Mechanical polishing of a copper alloy surface.
25. FIGURE 8.25 Laser ablation of copper surface.
26. FIGURE 8.26 Scratches through the protective layer and patina of three surface...
27. FIGURE 8.27 Packaging for Prada being prepared for shipping.
28. FIGURE 8.28 Steel corrosion products on several surfaces.
29. FIGURE 8.29 (Left, top right) Rust stains on cast sculpture; (top right) befor...
30. FIGURE 8.30 Blistering on the surface due to the core remaining inside the scu...
31. FIGURE 8.31 Antique light fixture before (left) and after (right) restoration.
32. FIGURE 8.32 XRF readings of the top section of the light fixture.
33. FIGURE 8.33 Cleaning the copper stain from a limestone base, before (left) and...

Preface

The passage of time is reflected in the color of copper.

Of all the metals used in art and architecture, copper is the most engaging.

Throughout history, mankind has had a special relationship with copper. Copper has a weight and feeling of substance. It can be shaped and formed into useful objects, and more importantly, it has an appearance as natural as the colors of an oak forest in the fall: a color that shows value and the passage of time.

Power and force are needed to shape the other metals used in art and architecture. Copper, on the other hand, shapes and moves under the blows of handheld chasing tools. It can be easily folded, curved, stretched, and embossed. One gets close to the metal when working with copper.

Throughout human time copper and copper alloys have played different and expanding roles. Bronze sculptures of ancient deities and heroes have outlived their civilizations, even while resting under the sea for thousands of years. Copper has been mined by every major civilization and converted and cast into both useful tools and decorative statues.

The maritime world embraced copper alloys, particularly brass. Alloys with names such as Admiralty Bronze and Naval Brass recall a time when this metal served as biocladding on the underside of a ship and ornamentation on the top. Consider that the military term “brass” relates to someone of high rank: the one with the brass metals or the brass‐adorned hat.

Copper alloys, both those with new, untarnished surfaces and those with colorful patinas, offer the artist and the designer an amazing palette of color to choose from and design with. Oxide colors will be predictable to a point, but beyond that it is nature that will take over the design. These colors will also act as potent inhibitors of corrosion. But note that both natural, untarnished surfaces and beautiful patinas on art and architecture forms will require something additional—either in the form of a coating or in the form of energy applied from an elbow—to keep them looking good.

I have worked with copper and many of its alloys for decades. I have hammered it, cut it, welded it, and shaped it into beautiful pieces of art. I have experimented with creating color on the surface of the metal with chemical interaction, heat, and selective electroplating. I have worked with friends to cast it and I have formed its sheets to create incredible surfaces.

Copper is special for its amazing ability to be shaped and stretched and for its ability to react with other elements and compounds to achieve a unique and beautiful surface.

Copper can be cast into glass, and the glass accepts it. It can be severely shaped, and it yields to take the new shape. It can withstand the attack of powerful acids and bases, all the while forming a natural mineral surface that slows further reaction while giving a beautiful patina.

This is the third in a series of books on metals used in art and architecture. I have attempted to cover many of the copper alloys that have found their way into use in art and architecture. New and innovative uses of the metal, along with advances in fabrication techniques and a renewed interest in patination, are fueling a renaissance in the use of copper alloys.

It is the surface of copper alloys—the part that interacts with the environment and the part that absorbs and reflects light in unique and special ways—that we find interesting as a material of design. But industry is also looking for ways of capitalizing on the antimicrobial benefits of the copper alloy surface. Tests have proven bacteria and viruses do not thrive and will diminish when in proximity to copper ions.

The corrosion resistant behavior of the copper alloy surface is unmatched. Few corrosive materials can get through the protective behavior of the oxide surface. All of this is an important and essential quality of the metal, but it is the unique color that draws us to it. There is no other metal that comes close to the intense beauty of copper alloys.

The early alchemists associated each of seven metals with a planet. Copper, one of the oldest metals known to man, was associated with the planet Venus, one of ancient man's “wandering stars.” Copper was thought to represent the characteristics of feminine beauty, caring and nurturing, love and lust.

The symbol for copper is the female symbol that is also the symbol for the planet Venus.

Photo depicts the symbol for copper that is also the symbol for the planet Venus.

The book is intended to give the artist and designer more knowledge about copper, its alloys and this amazing surface. Those who are interested in the metal will acquire information on how to work with the different copper alloys, how they will interact with the environment with time and exposure. Copper and copper alloys have a vast history, but the story is far from over.

ZAHNER'S ARCHITECTURAL METALS SERIES

Titles in Zahner's Architectural Metals Series include:

Copper, Brass, and Bronze Surfaces

A Guide to Alloys, Finishes, Fabrication, and Maintenance in Architecture and Art

Preface