Remove interior stops and exterior trim/molding carefully
Remove old glazing compound or sealant completely from the sash and frame
Cut and remove any failed caulk lines around the window perimeter
Scrape and clean all surfaces until free of old sealant, dust, and loose debris
Inspect for damage: replace rotted wood, repair cracks, and correct warped sashes/frames
Dry-fit the sash and confirm proper operation and drainage paths
Clean with a suitable solvent/cleaner and let surfaces fully dry
Mask edges with painter’s tape for clean sealant lines
Apply new backer rod where gaps are deep enough to control sealant depth
Apply primer if required for the selected sealant and the substrate
Apply exterior-grade window sealant or glazing sealant in a continuous bead
Tool the bead to ensure full contact with both surfaces and a smooth finish
Reinstall glazing material (glass setting blocks/spacers as needed) and set glass if resealing glazing
Reapply glazing compound or glazing sealant around glass edges to the required thickness
Reinstall stops/trim securely and evenly
Apply paintable caulk to the exterior joints where trim meets the frame (if applicable)
Remove masking tape before the sealant skins over
Allow full cure time per manufacturer instructions before exposure to water or painting
Check for proper weep holes/drainage and keep them unblocked
Seal any remaining small gaps with matching sealant as needed