Contemporary Collections: Preprints from the AICCM National Conference 17th g 19th October 2007 Brisbane pp. 25-30
Abstract
Howard Taylor’s The black stump (1975) is a reinforced concrete, exposed aggregate and glass tile sculpture which was originally constructed for St George’s Terrace in Perth and relocated to the University of Western Australia.
Corrosion of the steel reinforcement due to a combination of high chloride levels and inherent vice had resulted in concrete cracking and tile loss. A major source of chlorides was exposure to bore water, which had also largely obscured the decorative elements. Another contributing factor was the ingress of ground water due to the buildup of soil and debris in the large gap between the sculpture and the foundations.
A previous sacrificial anti-graffiti coating was removed using a hot water pressure washer, greatly reducing the bore water staining. Further iron staining was chemically removed and missing tiles replaced using commercial products. Losses in the terrazzo finish were replicated by adding black marble chips to a cementitious repair compound and polishing with a diamond disc. A silane sealer was applied to enable the concrete to breathe and dry out, while preventing further ingress of water. Galvanised angle iron collars were installed to prevent soil building up between the sculptures and foundations. The sculpture was also coated with a sacrificial anti-graffiti coating. The area around the sculpture is to be paved, making bore watering unnecessary.