Stain Glass Restoration
You may have noticed while looking upward in the nave recently (we hope you do once in a while) that the large stained glass window in the east has been removed. This window is often called “The Children’s Window” because it was funded by contributions from the children of the parish. It is being restored by Cathedral Crafts of Winona, MN.
Leaded glass windows are composed of many individual pieces of glass. They are held in place by frames made of lead called “lead came”. The came has a cross section like a capital H, so it has two channels to hold pieces of glass together. The came is soft enough to be bent to follow the shape of the glass pieces. At joints, where 3 or more come together, they are connected by soldering (melting of a lead & tin mixture) so they become rigid.
In the restoration process, Cathedral Crafts builds a scaffold to reach the window conveniently and safely. Then the entire window is taped over with duct tape to ensure that pieces of glass will remain in their precise position. Once secured, the window is removed from its wood frame by removing a wooden window stop on the inside of the building. In our case, the window being restored consists off about 7 separate panels. Each of these panels is removed as a single duct-taped unit.
When the panels arrive at the studio, a rubbing is made of the window to make a ‘map’ of the window. Then the window is deconstructed. The duct tape comes off, each piece of glass is separated from its caming and is immersed in a bath solution for cleaning and removal of bits of lead. When all pieces of glass are cleaned and inspected, the window is reconstructed using entirely new lead caming and solder. Broken pieces of glass are either repaired, or replaced with newly cut stained glass that precisely matches the color of the original. As the window panels are put together, the map from the rubbing taken earlier is used to ensure it goes back together in exactly the same position it was in before. For the larger spans, some additional bracing is added to the window before it is lifted. A sealant is also used to bind the lead caming to the glass both to prevent infiltration and to make the final assembly stronger.
Then, the installation process can begin. The existing wood frame is carefully examined, and any portions of it that have suffered too much from the weather can be replaced. Cathedral Crafts has a full wood shop and can produce almost any custom pieces necessary to ensure the frame holding the restored window is worthy of the task. Scraping and painting is part of the frame preparation. Once the frame is ready, the stained glass panels are returned to their original positions and secured.
The final step, then, is an option we decided in favor of; placing a protective shield over the exterior of the window. This is basically a storm window, and dramatically improves the thermal efficiency of the unit. A stained glass window by itself, consisting of so many pieces held together somewhat loosely, has more heat loss than even a single pane window. Such windows are certainly inadequate from an energy perspective when living in the north as we do.
Check Out Some Of The Hard Work
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