How to Repair Glazed Windows

Learning how to repair glazed windows takes preparation but the techniques are straightforward. Wood windows are the easiest and most practical to repair. Aluminum and vinyl present varying degrees of difficulty. The following techniques are the most common.

1. To repair glazed windows without glass removal, use a firm-bladed putty knife to remove the old putty. Avoid gouging the frame or scratching the glass. If the putty is hard to remove, soften it with a bit of linseed oil or a heat gun. Remove the metal glazing points. Clean the area well and go to step 3.
2. If you take out the pane(s), loosen the putty as in Step 1, being sure to avoid glass breakage or scatter with masking tape or suction cups. Remove the glass carefully, especially any broken pieces. Clean the resulting opening to remove any old putty and loose debris. Apply a bead of putty around the entire opening and carefully put in the pane, pressing down until some putty shows around the back side.
3. Insert the metal glazing points evenly followed by a bead of putty around the entire frame, packing it in well. Smooth the putty with the putty knife and/or fingers until the seal looks unbroken with no gaps or bubbles.
4. Clean any residue from the glass back and front until only an even line of putty surrounds a pane of clean glass.

To physically see how it's done, YouTube provides many excellent techniques online.