2torial #0515: Learn2 Repair a Broken Window (Continued) Seal it up Apply putty all around the edge of the glass, so that it fills the rabbet. Take the putty knife, and smooth the putty. Ideally, the putty will form a 45 degree angle between the edge of the rabbet and the glass. If the knife sticks to the putty, wet it to reduce friction. Be neat and tidy. Step 4