Stained Glass Windows Update
posted on Friday, July 8, 2016
The restoration of the windows is winding down. All of the south clerestory and aisle windows have been installed, as has the rose window. The windows of Andrew Hall are being installed now, and the gallery windows will be installed in August. Scaffolding is still in place, making it difficult to see the windows, however.
The video shows the start-to-finish process of restoration of the windows of St. Thomas Church, from removal through documentation and restoration, to reinstallation.
February 2, 2016
Installation of the stained glass has begun in earnest and will continue non-stop into the summer. Window C8 was installed in October, and watertested in January. Window C9 was completed at the end of January, and C2 is underway, to be followed by C6.
Panels at the bottom of the center lancets of the windows, most of which contain the dedication, have been strengthened by the addition of flat bars bent to follow the contours of the lead. These will keep the window from folding along the parallel lead-lines, a common area of deflection. (Fig. 1)
Despite their large size, the clerestory windows have an average of 100 pieces per square foot, for a total of about 14,500 pieces per window (Figs. 2 and 3).
Because the windows will not have protective glazing (like storm windows), which would negatively impact the appearance of the church, the windows have to withstand wind-blown rain. To simulate this, we have created a rig consisting of a horizontal pipe with a number of nozzles aimed at the glass. The rig is attached to a water hose. Starting at the bottom of the window, water is sprayed for 20 minutes. Any leaks are marked, and are re-waterproofed the next day, after the window has dried. This process ensures that the windows will not leak during ordinary or even strong rain storms.
December 2, 2015
Window C8, the second window from the west end (the chancel) was installed in mid-November. There are a few more details to complete on it. Window C8 commemorates “The Preachers.” The great figure in the center is John the Baptist, with the lamb above him (figs. 12.2.15 1 and 12.2.15 2). Other preachers shown include St. Peter and St. Paul, St. John Chrysostom, St. Augustine of Hippo, and St. Bernard, as well as John Wycliffe and Archbishop Laud. The small details make these windows sing. The red shield declaring “Spiritus Gladius” brightens the background (12.2.15 3). The tracery is full of leaves, crosses, stars, and Art Deco-esque patterns.
The clerestory windows are 35 feet tall, and have at least six levels of scaffolding on the interior and exterior. Because the scaffolding is fully enclosed, it is difficult to tell how high one is from the floor of the church, or even the height of the window. Each panel of the lancets is about 2’ tall. They are set into grooves in the stone window frames. Each lancet has a gutter at the bottom to collect any water that may condense on the window. From the exterior, the new lead cames are sharp and defined. Fitting the panels into the window frames is painstaking process, requiring patience and a lot of fiddling to be make sure they fit well and cannot leak either light or rainwater.
The rest of the windows will be installed between January and May, 2016.
August 20, 2015
Restoration of the stained glass continues in the studios. Window C8, the second window from the west end in the clerestory, is almost complete and is scheduled to be reinstalled this fall.
With so many sections of glass – a typical clerestory window has at least 67 individual sections, and the rose window has 325 sections – identification of each section by number and/or letter is critical. For this restoration, we are using a numbering system shown in this diagram (8.20.15 1). But James Powell & Sons used a different system, as can be seen by the number “27” scratched in the original lead (8.20.15 2). Many of the sections are very small.
One of the first steps in restoration was the making of a rubbing to use as a map to locate every piece of glass. A copy of the rubbing is used as a glazing guide for the releading. It can be seen underneath the partially releaded section in 8.20.15 3. The different colored lines on the rubbing indicate different sizes of lead came. An almost completed panel is ready for soldering. The lead in the soldered panel is very bright. It will be burnished down to dark gray after waterproofing.
All replacement materials are carefully selected to match the original. New lead cames are meticulously measured using electronic calipers. Samples of both original came and the new replacements will be kept in the church’s archives. When glass has to be replaced because it is missing or too badly broken to be restored, not only the color and type of glass have to be matched, but the color and style of painting do as well. All new pieces of glass are signed and dated by the restoration studio so that future restorers will know which glass was replaced. All such changes are also recorded on the archival rubbings.
May 20, 2015
Removal of all of the stained glass is complete, and restoration is proceeding in the studios.
- The clerestory windows are covered with scrims with photographs of the windows. The rose window, on the left, is covered with the black tarp on the scaffolding (image 5.20.15 1).
- The rose window was the last to be removed (image 5.20.15 2). Every section was labeled and the windows were cut out of the frame, leaving the putty in place.
- Some of the rose panels have been removed, and some are still in place. The black plastic tarps on the interior scaffolding are visible through the openings. The panels of the rose window, like those of the 53rd Street windows, are very bowed. The board held across the top is straight. The center of this section is bowed about 1-1/2” away from the board.
- (image 5.20.15 3) A clerestory window by James Powell & Sons, Whitefriars, London. Whitefriars made all but two windows in the church.
- (image 5.20.15 4) A panel of a clerestory window before cleaning or dismantling. Narrow border pieces were sacrificed during removal and will be replaced. We are numbering the sections to keep track of where they go. The original panels were similarly labeled, usually by scratching the number in the lead came. In window C7, the only window on the south side not made by Powell’s of Whitefriars, the panel numbers were scribed on 1/2”-long lead tabs by the D’Ascenzo Studio of Philadelphia.
- To clean the windows and to control the lead-containing dust, the windows are first soaked in a warm, soapy water. This can be safely done because the painted designs were well-fired and are not at all fragile. The lead came is being totally replaced, so the old came has to be separated from the glass. In the clerestory windows, the cames are very large and heavy. They are cut apart using snips, chisels, and power tools (image 5.20.15 5).
- During disassembly, the panels are kept wet by spraying them with water. They are sitting on top of pads made of materials similar to disposable diapers that hold the water. When the pieces of glass are taken out of the cames, they are clean from having been soaked. They are placed on a wooden tray, on top of a copy of the rubbing in the same order they are in the window. Each section, or part of a section, is on a wooden tray. The trays are stored in vertical racks.
- Powell’s of Whitefriars made most of the glass used in these windows. One type of glass was called Norman slab. It was blown into a mold shaped like a square bottle about the size of a Clorox bottle. The panes were very think in the center, and of brilliant, sparkling color. Here the different thicknesses of glass are visible.
- Unless the piece is totally shattered, all broken glass is being repaired using black silicone adhesive. The black adhesive is less visible than clear would be, because the glass is heavily painted and the clerestory windows are located 60’ above the floor of the nave. The pieces are put on a light table so that they can be properly aligned. Each piece is labeled so that it can be returned to the correct location.
- The lead came is being replaced with new came that exactly matches the original in all dimensions and in shape.
- This section has been waterproofed. A thick putty made of linseed oil, whiting (chalk), and lamp black was pushed between the glass and the came to keep the rain from leaking through the window. The waterproofing darkens the lead.
- Some of the most interesting windows are the smallest ones in private offices. A pair of diminutive windows in Douglas Robbe’s office are quite unusual (image 5.20.15 6). They are about 12” x 48” and depict Jesus and St. John the Baptist as young children. The leading is very ornate. On the inside surface, the came has been modeled to create rounded openings. On the outside of the same area, the real shapes of the pieces of glass are more obvious (5.20.15 8).
- This is even more evident in the rubbings. Another unusual feature are the many different sizes of came. Each color indicates a different size or profile – 8 in all. By contrast, the average clerestory window has only 4 or 5 different came sizes.
April 13, 2015
All of the clerestory windows have been removed and are now at their restoration studios. Several studios have begun to take them apart, getting samples of the original lead came sizes to have matching cames custom made. (The came is the H-shaped strip of lead that holds the pieces of glass together. The glass is slipped between the parallel legs of the came, and the ends of the metal are soldered together.) The windows in Andrew Hall are currently coming out. In addition, the “Choirboys” window on the Great Stair between the church and the parish house was removed, as were small windows in the rector’s office.
Removal of the rose window is expected to start next week. The protective glazing was removed a couple of weeks ago so we can clearly see what the conditions are. The windows have water staining where rain penetrated the protective glazing and dripped down the face of the window. White stains, which are residue from the stone and mortar, were leached out by the rain.
We are all glad that warmer weather is finally here!
March 14, 2015
Half of the clerestory windows have been removed and delivered to the stained glass studios that will restore them. The clerestory windows are approximately 24’ wide and 35’ tall. They are made in small panels, about 32” wide and 24” tall, so that they can be handled easily. They are not framed. Each panel was set directly into the stone window frame. When they are removed, they are put into a labeled wooden crate. This is how they are shipped to restoration studios, and how they will be returned. When they arrive at the restoration studios, they are unpacked and documented. They were thoroughly photographed in the church before they were removed, and now they are photographed again. Every photograph contains a label identifying the section, and a scale for size. After photography, every section is rubbed by putting a sheet of 100% rag vellum over the panel and rubbing it with a wax crayon to record the impressions of the lead cames. This creates a map to locate every piece of glass and record all the different sizes of lead, shown here in different colors. All conditions are recorded on the rubbings, including breaks in glass, missing paint, and bar locations. It is tremendously exciting to see the panels up close. Image 3.14.15 1 is the face of Nathaniel, “an Israelite indeed in whom there is no guile” (John 1:47), from the St. Thomas window, the only one in the church not created by James Powell & Sons, Whitefriars, London. St. Thomas was the first window installed in the church, in 1927; it was designed and made the Nicola D’Ascenzo Studio in Philadelphia. The windows are identified during restoration by numbers (3.14.15 2). St. Thomas is C7, third from the chancel. The windows marked in red are those being restored in this phase of the work.
March 4, 2015
The scaffolding starting going up on the 53rdStreet side of the church in late October, and wrapped around the corner to Fifth Avenue in December. Exterior scaffolding on the rose window is now underway. While the scaffolding was being erected, the site-work studio, Northeast Stained Glass of Newton, NJ, was building crates for shipping the windows to the various studios that will be restoring them.
The first step in removing the windows was to take off the protective glazing that had been installed in the 1980s. Then the windows were photographed extensively – outside, inside in transmitted light (with the light coming through the glass) and in reflected light (with the light reflecting off the surface of the glass). These steps have been completed for all of the 53rdStreet windows.
Removal of the stained glass began on February 17 at the west end of the clerestory. The two western-most windows have been delivered to the restoration studios: “The Builders” window has gone to Studio Restorations in Long Island and to E. Scott Taylor in Richmond, VA; and “The Preachers” window to Serpentino Stained and Leaded Glass in Boston. By February 27, the third window from the west, “St. Thomas,” will be removed and sent to Diane Rousseau Restorations in North Adams, MA. The weather has been interfering with the work, producing arctic temperatures and ice and snow on the scaffolding.
We expect the windows to be reinstalled during the spring of 2016 and, shortly after that, the organ replacement project will kick into high gear.
More on the history of the Saint Thomas Church building
- Get more information about our beautiful church building
- Learn about the first Saint Thomas Church building
- Quick facts about Saint Thomas Church