Window glazing is the hardened putty that holds a pane of glass in the frame. Glazing is a soft, pliable putty when installed. The glazing becomes very hard and brittle over time. When a window pane cracks, you'll need to remove the glazing before you replace the window pane glass. When removing window glazing, be careful not to damage the window frame and incur a costlier repair.
Direct a heat gun onto a section of window glazing. Do not overheat. Overheating the frame can cause the glass in the adjoining frames to break.
Scrape off the softened window glazing with a putty knife. Hold the putty knife at a right angle to the groove, called a “rebate,” in the frame and cut the glazing at the edges of the frame. Slide the edge of the putty knife across the rebate behind the glazing to lift the heated glazing off the window frame.
Repeat Steps 1 and 2 until all of the glazing has been removed.
Scrape the remaining glazing off the frame by gently rubbing with the blade of a utility knife.
If possible, remove the window sash from the frame and place the sash on a solid work surface to remove glazing.