An aqueous cleaning system with diammonium citrate, triethanolamine, and Triton XL 80N surfactant adjusted to a pH around 7.5 with ammonium hydroxide was used to successfully clean the companion portrait. This system was tested and found to be equally successful at addressing similar issues on Capt. Trent of embedded grime and uneven surface sheen possibly due to previous oiling out. The raking light detail (left) of the lower left corner before treatment emphasizes these surface characteristics and highlights local areas of overpaint associated with damage to the canvas.
Dark areas (such as the garments) were cleaned only with saliva to avoid potential adverse interactions with the chelating solution as these areas likely contained Prussian blue.
This during cleaning detail (left) demonstrates how the chelating solution greatly reduced the appearance of a checkered pattern possibly from previous oiling out.
Consolidation of flaking paint with 2% isinglass in deionized water proceeded simultaneously with surface cleaning. After heat-setting the adhesive, the local area of application was set to dry under weight with a non-woven release sheet, blotter and plexiglas block.
All images related to this project are presented here courtesy of The Colonial Williamsburg Foundation