Part 1 on the history of the Altarpiece is here
On Sept 18, 2014 L. Cleo Mullins of the Richmond Conservation Studio visited the church for the purpose of an examination of the tablets and proposing solutions due to problems she uncovered. Her resume is here.
Her full report is here along with a gallery of photos. The following is a summary of her report from her own words based around the problems she found and suggested next steps:
Problems
1. Moisture and earthquake(s)
The altarpiece and the wall to which it is attached have suffered from moisture damage due to leaks along the roof flashing and most recently, due to shaking and settling of the building due to earthquakes.
There are cracks in the wall and plaster framework, which should be addressed.Recent damage due to earthquakes has caused fracturing in the lower left corner and upper left edges of the framework, where there are new cracks and chips. There are several areas of prior damage and loss to the molding with a large section missing from the inner edge of the left-most arch. These areas have been painted over with brass paint.
The roof needs repair as the moisture in the wall is causing the painted areas of plaster to flake and the wooden tablets to bow, crack, and lose paint along the wood grain.
2. Previous efforts to restore- painting over.
The altarpiece has also been severely damaged by well meaning, but poorly conceived and executed restorations. The framework, central panel, pinnacles, and angel corbels have all been extensively altered by overpaint.
3. Wooden panels
Two of the panels are bowing visibly and appear detached at the top.
The paint and ground layers are cracking, exposing the ground and brighter blue of the field.
Fine lines of loss and flaking are found along these cracks due to compression as well as along the grain of the wood, which runs vertically. Deterioration is more advanced in the warped panels. The left panel of the right pair has a splinter along its right edge with a scrap of white cleaning cloth stuck in it, indicating that someone has been wiping the panels
4. Painted Pinnacles
These decorative panels have been solidly overpainted with a dark maroon or reddish brown-colored paint
Divots in the overpainted surface indicate that there was previous flaking of the original surface. This is especially true of the right panel, which shows extensive losses
Deterioration in this panel is obviously active and on-going. There is a large crack extending through the lower edge of the frame and up into the painted panel.
Solutions
1. Wooden panels The wooden panels can be removed from the wall and brought to the conservator s studio, where they can further be examined and then treated
Probable treatment would include glueing and strengthening the wood along the checks and cracks in the panels. Sealing the reverse and edges of the panels with synthetic resin varnish and wax to stabilize the wood and serve as moisture barriers. Local consolidation of the paint and ground where flaking has occurred. Cleaning of the paint surface, then varnishing it with a clear synthetic resin. Inpainting (retouching) of the losses to match the surrounding extant paint
2. Framework and gild -I would recommend that the conservators then return with Russell Bernabo, Gilding Conservator, who can assess the framework and gilded areas. More test cleanings should be made to assess the condition and possible treatment of the pinnacles, central panel, and framework.
3. Central panel Work which must be done on site includes the treatment of the painted plaster central panel and pinnacles and the framework. Test cleanings already made suggest that the maroon overpaint on the painted plaster panels can be removed. If further tests confirm that this is safely possible, then the overpaint should be removed. The surface can then be consolidated, varnished, filled, and inpainted. An estimate for this part of the treatment cannot be given until after further tests and examination are completed.
4. The plaster framework and corbels are very much in need of repair and cleaning. The original surface treatment of the framework and corbels must also be determined. Probably treatment can be expected to include removal of the added paint and other accretions from the surface, repair and stabilization of the cracks in the plaster, restoration and filling of the missing and broken areas of molding, and restoration of th surface to an approximation of its original appearance. Hopefully, Russell Bernabo will be able to propose a treatment that is feasible for the church.
History – Two items found in passing
1. A nail hole at the center of the cross suggests that something was once hung there
2. Test cleaning of the background with methanol and dimethyl-formamide showed that the field behind the letters and cross was originally a bright cerulean blue-color, but it has been painted over with a dark maroon or reddish-brown colored oil paint, probably the same paint used when overpainting the pinnacles.