The Boppard stained glass panels have now all been photographed and every square centimetre of the 35 leaded and painted panels have been scrutinised from the front and back.
We have assessed the structure of each panel, looked at the condition of the glass, paints and lead and even the frames. We have recorded the details of any restorations and tried to work out when they were added.
Most of the panels are structurally very vulnerable. The lead used in the restoration of 1871 was very thin with not much body (less material = less cost) and as a result it is not very rigid or strong. It also does not provide any space for putty to be inserted so there is a lot of lateral movement in the panels especially when they are removed from their frames.
The original design incorporated few leads and large glass pieces and subsequently there has been damage to the glass and repair leads have been added, as in the image above.
In other places broken or missing glass has been replaced by a restoration. The face above was probably inserted as part of the restoration carried out in 1871. But later someone must have thought that it was too pale and added a brown wash to tone the glass down. The problem with the wash is that it has not been fired, so it is very unstable and can easily be removed – as has already happened!
In other areas where restoration glass was inserted, an unfired “wash” was applied from the back to help disguise the restoration. What is puzzling though is why this wash was applied to the lead as well. These sorts of findings raise the question whether the panels underwent significant restoration while they were in the Hearst and or Goelet Collections. It will be interesting to trace down some of the firms that carried out the work.
Some preliminary cleaning tests have been carried out as all of the panels are very dirty. The cotton swab in the picture above was moistened with water and synperonic A7 (a mild detergent) and even after several applications the swabs still turned black very quickly.
We have looked at paints under magnification….
… and studied glass corrosion.
On the whole the panels have been left in their frames for now. The only exceptions have been made where it is clear that a panel will have to come out of its frame anyway for treatment.
The frames are interesting in themselves. In the case of the windows William Burrell bought from the Hearst Collection (Tree of Jesse Window and the Two Standing Saints) the frames seem to have been added by Wilfred Drake in 1938, whereas the frames for the window bought from Goelet (Ten Commandments Window) the frames probably predate the sale of the window in 1939. We are definitively going to keep them for now and if possible we will try to reuse them.
Over the next 2 months the hundreds of photographs will be organised and filed and research questions will be summarised. At the moment it seems like there are more questions than answers!