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May 24, 2023

A Bright Future for Bronze Form

What it takes to protect Henry Moore’s iconic outdoor sculpture Steve Roy, an expert in bronze patination, sits on scaffolding beside Henry Moore’s Bronze Form. Reproduced by permission of the Henry

What it takes to protect Henry Moore’s iconic outdoor sculpture

Steve Roy, an expert in bronze patination, sits on scaffolding beside Henry Moore’s Bronze Form. Reproduced by permission of the Henry Moore Foundation

By Cassia Davis

It’s rare for a sculpture at the Getty Museum to be refinished.

But when Henry Moore’s Bronze Form showed signs of degradation and corrosion, it was time to act.

First, a little background on bronze.

When they’re new and polished, bronze sculptures are bright and shiny. But this surface can quickly change depending on the environment. A patinating solution helps to protect the bronze from degradation and unwanted corrosion. This creates a protective layer called a patina.

So what happens when bronze is unpatinated? Take a look at the story of Bronze Form.

Brushes and chemicals used for creating a patina

A bronze surface showing different layers of finishing and patina

Reproduced by permission of the Henry Moore Foundation

Bronze Form is a large sculpture that greets visitors to the Getty Center. It is one of a series and was actually fabricated after the artist’s death in 1986 by Morris Singer Foundry and managed by his studio assistant, Bernard Meadows. In a controversial move, Meadows asked the foundry to leave the surface of Bronze Form unpatinated.

In 2012 the sculpture needed to be recoated with varnish to maintain its appearance, but by 2021, that coating had started to break down again. The surface began to tarnish and corrode unevenly. It became clear that a new approach was required to preserve the sculpture.

Bronze Form, 1985, Henry Moore. Bronze, 13 ft. 11 1/2 in. high. Getty Museum, Gift of Fran and Ray Stark, 2005.117.1

Reproduced by permission of the Henry Moore Foundation

The top half of Bronze Form is how the sculpture appeared before treatment in 2021, and the lower half includes several patches to test different patinas in Getty’s environment.

Getty Museum conservators partnered with Andrew Baxter and Steve Roy, experts in bronze casting, fabrication, and the application of patinas to design a treatment plan for the sculpture.

Baxter and Roy had extensive experience working with Moore’s sculptures and were excited to be a part of this project.

“l enjoy all facets of what l do, but restoration is probably my favorite,” Roy said. “Bringing a work of art back to life is rewarding.”

Roy heats the surface of Bronze Form to prepare it for patination.

Reproduced by permission of the Henry Moore Foundation

A patina was necessary to meet the specific needs of Bronze Form and its environment. The goal was to create a long-lasting color true to Moore’s work and a protective coating built to withstand Southern California’s weather.

Over the course of a year, the conservation team conducted tests to determine what chemical solutions and patination methods would work best.

Reproduced by permission of the Henry Moore Foundation

Before applying the new patina, even more preparation was needed. First, a large enclosure was built around the sculpture to protect the stone panels that surround its base, as well as to provide a scaffold the conservators could use for lacquering the sculpture during the final stages of treatment.

Bronze Form, 1985, Henry Moore. Bronze, 13 ft. 11 1/2 in. high. Getty Museum, Gift of Fran and Ray Stark, 2005.117.1

Reproduced by permission of the Henry Moore Foundation

Getty built a large enclosure around the sculpture during the treatment.

Next, the entire sculpture was carefully sanded down to reveal the golden color of the underlying metal. This process also removed the corrosion on the exterior and provided an appropriate surface to which the patina could bind.

Roy sands down the sculpture to remove the corroded surface and prepare it for patination.

Reproduced by permission of the Henry Moore Foundation

While the sculpture was bare, conservators used a device called a portable X-ray fluorescence spectrometer (XRF) to help identify the type of metal used to make the sculpture.

A Getty Museum conservator uses a portable x-ray fluorescence spectrometer to find out the exact materials Bronze Form was cast from.

Reproduced by permission of the Henry Moore Foundation

Conservators found that Bronze Form was cast from a metal alloy consisting of copper, tin, zinc, and lead. Understanding the materials shed light on how the patination chemicals would interact with alloy variations on the surface.

Reproduced by permission of the Henry Moore Foundation

Next, some chemistry.

Baxter prepared two different chemical solutions in his pop-up lab beside the sculpture enclosure.

Baxter looks through notes about previous test locations of different patinas.

Close-up of cupric nitrate

Baxter measures out cupric nitrate.

Close-up of ferric nitrate

Once the chemical solutions were ready, Roy began the delicate patina application process.

First, he heated up an area of the surface of the bronze. Then, he alternated between applying one solution and the next using smooth strokes of a flat brush, or stippling with a stiffer round brush.

After several hours of application, the patina created the slightly translucent, golden-brown color characteristic of Moore’s sculptures.

For Roy, the biggest challenge was “to get a patina that was rich and pleasing to the eye, while at the same time keeping it in a lighter tone.”

This work will allow the sculpture to retain its bright hue even though the outdoor environment means the color may change over time.

Moore was aware of the effects of the elements on his work. “My own patina is, of course, a preliminary to the one which nature will herself supply in time,” he once said.

The patinated area contrasts with the raw bronze.

Reproduced by permission of the Henry Moore Foundation

As a protective measure for the patina, the team coated the sculpture by spraying it with an acrylic lacquer.

Getty’s sealed tent with air filtration was created to prepare the sculpture for varnishing.

After the lacquer was applied, Roy finished the base of the sculpture by heating the surface and applying pigmented wax with a brush.

Roy uses heat and wax to finish the sculpture base as well.

Reproduced by permission of the Henry Moore Foundation

Reproduced by permission of the Henry Moore Foundation

After many years of research, testing, and work, Moore’s Bronze Form once again reflects the artist’s intent. It’s now well protected and, with regular maintenance, will be available for visitors to enjoy for years to come.

Baxter and Roy look up at the finished patination on Bronze Form.

Reproduced by permission of the Henry Moore Foundation

Learn more about the conservation of Henry Moore's outdoor bronze sculptures.