The conservation of 13 nineteenth-century oil paintings on zinc panels by Sir Ninian Comper

Thirteen oil paintings on zinc panels by Sir Ninian Comper (1864-1960) were analysed, tested and treated by Hirst Conservation Ltd in the UK. These nineteenth-century paintings had suffered severe galvanic corrosion of the metal fixings used to hold them in place in a fourteenth-century reredos in St Mary Magdalene Church, Geddington, Northamptonshire. There is little information available on conserving oil paintings on zinc since most artists opted for copper substrates when painting on metals. The studies that were able to be accessed during the treatment of Comper's panels differed considerably in terms of circumstances, methods and the materials chosen. Substantial consideration, testing and consultation with experts in various conservation disciplines was therefore required to implement a successful procedure for the paintings. As such, the treatments were carried out without the use of any water or aqueous-based materials, as part of mitigating risks to further corrosion. This article is presented to identify and address some of the gaps in information for conserving oil paintings made on zinc substrates.