If you are renovating an older home chances are you have a stained glass window
in your home. Stained glass has always been status symbol- an added extra
that not everyone could afford.

    For the first half of the 1900's the windows were usually ordered from catalogues. I know that companies existed in Minneapolis and Chicago for this purpose, and I would imagine that many companies in Canada sold their windows. Some of the most beautiful of these windows featured hand painted birds or beveled glass designs in the center of the panel.

    The windows are assembled using an extruded lead channel called lead came. Came comes in the shape of an H and the glass fits it from both sides. Many pieces of lead must be cut and mitered to fit the design of the glass pieces in the window. This requires a great deal of skill on the part of the glazier. Lead was used because it was inexpensive and easy to bend so a good glazier could assemble a number of windows in a day. However lead has one inherent problem- once it stretches it will not contract. If you have a window which is facing south, the heat from the sun will heat up the lead and glass dramatically causing the lead to stretch and eventually dry out. As you can see in the photo the lead at the bottom of the window has stretched and the window has bowed out cracking numerous pieces of glass. The glazier who built this window would not be surprised. He knew that depending on the exposure of the window, the amount of moisture present, the amount of pollution in your part of the world and the size of the window, after 50 to 100 years the window would need some TLC. In this case the window was removed from the wooden frame, carefully flattened and the broken pieces were replaced with modern glass with a tint and texture as close to the original as possible. This work can be done by a professional for a few hundred dollars. If the lead was more brittle the window would have to be pulled apart and rebuilt with new lead which can be considerably more costly.

    If you wish to transport your window to a stained glass studio for repair you should remove the entire sash so that you don't damage the stained glass. Removing the glass from the sash is a tender job. If you decide to try here are some hints.
> Carefully remove all the putty from the sash. Use either a chisel or sharp putty knife to pry all the loose putty away.

> Always place your tool against the wood sash not against the glass. If you have to apply pressure, do this at a spot where there is a piece of lead separating two pieces of glass. If the chisel slips you are more likely to hit the lead and less likely to break glass.

> Once you have all the putty out remove all the little nails which were placed to hold the glass in the sash. These are usually positioned at a spot where a piece of lead separating two pieces of glass joins the lead border- perpendicular to the sash. I use a pair of wire cutters to pull them out.

> Once the nails are out you should be able to carefully remove the window. If it is starting to fall apart stop what you are doing and apply strips of 2 inch masking tape completely covering one side of the window to stabilize it and then continue.

> Once the window is out of the sash place the window on a piece of 3/4 inch plywood. Hammer 1x2 strips around all sides of the stained glass to secure it.

    Replacing broken pieces of glass on the border of a window isn't rocket science but you do need specialized equipment. A very sharp utility knife is used to cut the border lead. The broken glass piece is removed and used as a template to cut a replacement. After the glass is slipped in place the lead which was removed must be soldered back in place. This can be challenging as it has been heavily oxidized. Scour it with steel wool, apply soldering flux and resolder the lead pieces together using 50/50 or 60/40 solid core solder. Replacing interior pieces of glass is much more challenging and shouldn't be attempted without training.

    In the photo you can see that the metal support bar has pulled away from the window. This bar is supposed to be supporting the weight of the window. Over time the solder seams which attached it to the window have failed. It is no longer doing its job and the window is stretching and bowing out of the wood frame- often forward and backward. This is very common with older windows. The theory is that the flat steel rebar is soldered to the lead to keep the windowflat. On some older windows copper wire is soldered to the lead came and then twisted around round rebar. In either case the ends of the bar are notched into the wood frame so that the weight of the stained glass is transferred to the frame and all the weight of the window isn't pushing down on the bottom of the window. If you ignore this problem glass pieces will start to crack and pop out of the lead. It is often very difficult to match the colour and texture of old glass so you want to deal with the problem before it progresses.

Brian McMillan established Prairie Stained Glass in 1978. His firm is actively involved in building custom windows and lamps for homes and religious settings. They also offer a complete repair and restoration service.