
'Horse and Rider' 1983 by Robert Clatworthy before treatment

The horse's back legs viewed from underneath the sculpture showing green patches of corrosion

Detail of corrosion on horse's left back leg

Drilling a small hole to allow the video microscope probe to be inserted

Water that has collected inside the bronze drains from the hole

Inserting the video-microscope probe

The video microscope image showing a stainless steel bolt inside the sculpture in good condition

Tapping a screw thread to insert a copper alloy plug so that the sculpture can be drained in future if necessary

Carefully removing encrusted green corrosion from the surface

Washing the sculpture surface to remove dirt and bird lime

As wax is applied the white appearance of the corroded surface is saturated to reveal the original brown patina colour

Buffing the waxed surface on the bird´s wing

The sculpture after treatment

The sculpture after treatment

The sculpture after treatment

The sculpture after treatment

Robert Clatworthy
'Horse and Rider' 1983
This monumental bronze sculpture by Robert Clatworthy is on loan to Charing Cross Hospital from The British Land Company PLC. It is installed within a sunken landscaped garden in the hospital complex. Over the years, its original dark brown patina had developed a chalky green appearance. Imperial College Healthcare Charity Art Collection, which is responsible for the works of art on display at Charing Cross Hospital, had some concerns about the appearance of bright green patches of corrosion around the horse’s back legs and asked us to help.
We initially arranged a video-microscope probe investigation of the interior to help assess the cause of the problem before taking any further steps. This showed an accumulation of water, possibly due to condensation, which had been emerging slowly through small pores in the bronze and reacting to form green corrosion products on the surface. Fortunately, the examination also provided reassuring views of the armature, which appeared to be of stainless steel and in good condition.
After consultation with the clients we drilled unobtrusive small holes at critical points to drain residual internal water. The holes were then tapped with internal screw threads and filled with copper alloy threaded rod which could easily be removed, should any subsequent accumulation occur, before any damage could take place.
The green corrosion was then painstakingly removed. Areas where corrosion had damaged original patina were locally re-patinated to match the existing colour. We erected scaffolding so that our conservators could gain safe access to clean the entire sculpture to remove surface soils and deposits. Finally, a wax coating was applied to protect it from weathering damage in future. This treatment resulted in a great improvement in the appearance of this powerful bronze. Patina has since carried out a further cleaning and waxing treatment and a regular maintenance programme will now be undertaken to ensure that the sculpture can be monitored and preserved in the long term.
With thanks to:
British Land PLC, which funded this project.
Rosie Glenn, art curator and consultant.
Tessa Jackson, William Easterling, Justin Hill, John Bracken and the Patina technical team who assisted with the practical treatments.
The Art Collection team at Imperial College Health Charity for all their assistance in organising this project.
Artist | Robert Clatworthy |
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Name | 'Horse and Rider' 1983 |
Client | British Land |
Location | London |