If you have an old wood framed window in your attic, basement, or garage, you pray that the glass never breaks. However, a stray baseball or confused bird can easily crash into the window, shattering the glass and requiring a home repair. If you find yourself having to replace one of these windows, just follow the steps below.
You will need:
• Pane of replacement glass
• Metal glazing points
• Latex glazing putty
• Heat gun
• Flathead screwdriver
• 1 or 2-inch steel putty knife
• Flexible putty knife
• Tape measure
• Work gloves
• Safety goggles
Step 1: Use the tape measure to determine the length and width of grooves designed to hold the glass. Shorten the measurements by 1/8-inch on both length and width. This leaves a gap of 1/16-inch between the rabbet groove and edge of the window pane on each side. This gap offers room for glass to expand during warm weather.
Step 2: Put on the work gloves and safety goggles and remove the shards of glass with the pliers.
Step 3: Warm the old putty around the glass pane with the heat gun. Scrap this putty away with your steel putty knife. If it is difficult to remove, heat it again and try to scrape it a second time. The putty on an old window can be very hard so it may take several attempts to remove it.
Step 4: Remove the old glazing points buried in the putty, using the tip of the screwdriver or the steel putty knife.
Step 5: Clean the rabbet groove with the steel putty knife and inspect it to make sure no glazing points, shards of glass, or glazing putty remain.
Step 6: Use the flexible putty knife to apply a 1/16-inch bead of latex glazing putty between the window frame and the edge of the glass, working along the rabbet groove.
Step 7: Press down gently on the edges of the new piece of glass so the putty spreads and creates a moisture seal on the interior of the window between the sash and the glass.
Step 8: Position the window pane in the rabbet grooves, shifting it until there is a 1/16-inch gap between the sash and window pane on each side.
Step 9: Put two or more glazing points into each section of the sash around the new pane, spacing them evenly, approximately 6 inches apart.
Step 10: Push one corner of each glazing point into the sash with the screwdriver blade or flat side of your steel putty knife.
Step 11: Roll some putty in your hands to create a ½-inch thick rope. Press this along each side of the glass.
Step 12: Angle your flexible putty knife at 45 degrees and press and smooth the putty against the sash and glass. Scrape away any excess putty with the putty knife.
Step 13: Allow the putty to dry completely. Paint the frame and putty in the repaired area. Do not mask glass prior to repainting. The paint creates a moisture seal between the sash and pane of glass. Let the paint overlap the glass by approximately 1/8-inch.