The practical conservation work to all the windows within the chapel has now come to an end, with all stained glass having been removed, cleaned, and repaired. The most significant element of the conservation however, was the painting of backing plates to strengthen up the missing painted detail; the completion of this process now allows the windows to be read iconographically in a way that would not have been seen for about 80 years.
While the conservation work has been completed there are still three elements of the project under way; environmental monitoring, the installation of protective glazing and the insertion of a head from window eIII.
The protective glazing is required because the painted surface to the entire ground floor windows is still unstable and needs protection to secure its long term future. Over the past two years, a test bed has been in place to establish if the proposed installation would function and, following rigorous sampling and monitoring, both technical parameters and an exterior aesthetic appearance has now been agreed by Rosslyn Chapel Trust, Historic Scotland and Midlothian Council. A system of externally ventilated environmental protective glazing was chosen due to the significance of the internal carving around each window. This means that the stained glass will be relocated back into its original glazing groove and the window protection will sit within the exterior masonry, with a 30mm cavity. Ventilation will be provided by vent slots at the top and bottom of the protection system. The glass type chosen for installation is a tinted glass with an etched surface.
The final element of the works involves the installation of a newly painted head into window eIII. This head will be the culmination of the ‘Lost Image Research Project’ which was instigated to identify a more accurate method of bringing back completely lost painted detail, and then reproducing the missing image onto a new piece of glass. This is a very exciting and new development in stained glass conservation.