How to Replace Broken Casement Window Panes
- 1). Prepare the area around the window by placing plastic sheeting or a tarp on the floor. This will make cleanup of broken glass and old putty easier.
- 2). Remove the old glass. Since you'll probably have to remove the old putty anyway, try removing the putty first, to free the glass pane. If the putty is old and hard, or if the glass is badly broken, use a hammer or other tool to tap out the remaining glass.
- 3). Remove the old putty. Depending on the window's age, the putty may be hard and crumbly. There also may be triangular metal clips---sometimes called sash clips---embedded in the window frame. Remove or bend the clips out of the way. Remove the old putty by hand or using a putty knife, screwdriver or razor blade.
- 4). Brush away or vacuum any debris in the window frame.
- 5). Sand the window frame to create a smooth, flat surface to accept the new pane. There normally is a small "rabbit groove" that accepts the window pane, especially on wooden frames.
- 6). Insert the new pane into the window opening. Make sure it fits properly and that there aren't large gaps. Replace or secure the metal sash clips to hold the pane in place.
- 7). Apply putty or glaze to the window edges along the frame. Use a putty knife and your fingers to develop a consistent bead. The putty knife will create a smooth edge and remove excess putty; your finger can provide an attractive concave bead to the putty. Wet your finger, if necessary, before smoothing. You also can apply the putty or glaze directly to the window frame before replacing the new pane. Roll the putty between your hands to create a thin rope, apply the putty rope to the inner edges of the window frame, then seat the glass into the frame. Remove excess putty before it dries, using a putty knife and razor blade, before smoothing the bead with your finger. This method will also produce excess putty on the outside of the glass that you must remove.
- 8). Allow the putty to dry. Use a razor blade to remove any putty that remains on the window pane.
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