Restorations

Stained Glass Window Repair and Restoration

Restoration, repair, and preservation of old and existing stained glass windows is a necessary and critical task that makes up a large portion of our business. Stained glass windows have an average life span of about 70-100 years, depending on it's use and exposures. Large panels, and those in doors and ventilators may have a somewhat shorter life expectancy. If windows are incorrectly sized, or inadequately reinforced, they have a tendency to bow and sag prematurely, causing lead joints to weaken and crack, and glass to break.

Our philosophy on "historical" works and restoration is "The least amount of intervention necessary to make a window sound, is usually the best approach." There is a point, however, when the window has buckled or deteriorated to a degree that requires complete restoration. This was the case of the following project which involved the Clerestory windows at Christ Church Cranbrook, in southeastern Michigan. The complete steps in restoration process are as follows:

1) Panels are labeled and photographed in the original opening prior to removal to show visible damage and deterioration.

2) Individual sections are carefully removed from the stone openings by chipping away the mortar that holds them in the stone groove. The sections are packed and transported to the studio.

3) Sections are laid flat on a work bench and flattened as much as possible using gradual weight. The sections are closed inspected, and an evaluation from is filled out noting broken glass, bowed areas, and other details.

4) A rubbing is made by placing a sheet of heavy Kraft paper over the window and rubbing with a plat section of soft drawing lead. The raised leads create an outline for the Glazier to follow during reconstruction.

5) Panel is disassembled by separating old lead and glass. Old putty (sealant) is carefully scraped from each glass section. The cleaned section is laid in a flat box it's correct position.

6) If a glass section has one or two simple breaks, it is edge-glued back together using a special clear silicone glue. If a glass section is badly broken or missing, it is replaced by matching the color and texture. Glass paint is applied, and the glass section is fired in a kiln. The new painted section is placed in the box with the others.

7) Window section is releaded over the top of the rubbing, using new lead cames to match the old ones. When it is completed, all intersections (lead joints) are soldered on both sides of the window.

8) Panel is grouted (waterproofed) using a sealant made from common putty thinner with linseed oil. The grout is forced with a brush into the void between the lead and glass, and the excess is removed. The panel is finished by polishing with a section of burlap and calcium carbonate. This process is repeated on the opposite side.

9) Tie wires are installed in their original position as marked on the rubbings. These wires tie the panel to the reinforcing bars that are anchored into the stone framework.

10) Finished panels are reinstalled into the stone openings and tied to the reinforcing bars using the wires previously installed.

This project involved 18 Clerestory windows, consisting of 3 lancets each, with 5 sections or panels in each lancet. Each section took about 29 hours of labor to restore, plus removal and reinstallation time.

Windows were removed from the openings starting on Thursday, and boarded up. Scaffolding was removed from the premises prior to Sunday services. Church functions were not disrupted. Each 3 lancet as per photo took approximately seven weeks to complete. The entire project of all windows took approximately three and a half years.