DIY Interior Window Frame Repair

Assess the damage of the interior wood window frame. While small sections of rotted wood are easy to repair without professional assistance, you need to replace the frame if the damage covers an area greater than 10 percent.

Position the tip of a chisel against an edge of the damaged section and tap it with a hammer to dislodge the rotted, crumbling or loose wood. Continue to tap rotted wood until you reach healthy wood on all sides.

Brush the exposed section of the frame to remove residue and dust. Use a small paintbrush to reach deep corners and edges of the frame.

Push a 1/4-inch drill bit into a hand drill. Drill 1/2-inch holes through the sections of the healthy wood, spaced 2 to 3 inches apart.

Insert the tip of a paintbrush in a can of liquid wood preservative and apply it over the surface of the hollowed section of the wood frame and the drilled holes, starting from one corner and working towards the other. Use a small brush to work the preservative into the corners and dips in the frame. Allow the preservative to dry for five minutes.

Apply another coat of preservative over the damaged section of the wood frame and leave it to dry for five minutes. Continue this process until the wood ceases to absorb the preservative. The preservative strengthens the wood and provides a sturdy base for the epoxy filler.

Prepare epoxy filler according to the label directions. Pack layers of the filler into the hollowed section of the wood frame until it falls flush with the surrounding surface. Press each layer of filler lightly to remove trapped air pockets.

Insert the tip of a putty knife in a solvent and run it across the epoxy to shape it to the surrounding wood frame. Allow the filler to dry according to the time specified on the label’s directions.

Sand the cured epoxy to smooth out rough edges or inconsistencies so that it blends with the surrounding wood frame. Wipe away sanding residue with a tack cloth.

Prime the repaired section of the window frame and let it dry. Apply a coat of paint over the surface of the interior wooden window frame.