and high-quality exterior caulk (silicone or siliconized acrylic) Heat gun or hair dryer (optional, for stubborn old putty) Utility knife Mineral spirits and a clean rag Replacement glazing compound (if sealing glass to frame) Sandpaper (medium grit) Step 1: Remove the Old Sealant
Take a golf-ball-sized amount of glazing putty and roll it between your hands into a long "rope."
Once the bulk of the old material was gone, I used the wire brush to scrub away the grit and loose paint dust. The gap looked ugly now—a raw, open wound in the side of the house—but it was clean. I wiped the area down with a damp rag and let it dry. You cannot caulk over moisture; it traps the water inside, turning your window frame into a petri dish for dry rot.
