Step 4 · Repair Damaged Sash Components

For minor rot or cracks in the sash, carefully excavate the damaged wood using a chisel or utility knife until you reach sound wood. Clean the area thoroughly. If dealing with rot, use a wood hardener to stabilize the remaining wood. Then, fill the void with a durable exterior-grade wood filler or epoxy filler, packing it in firmly. For loose joints, you may need to carefully disassemble them, clean them, apply exterior wood glue, and re-clamp them until dry. If you had to add significant filler, allow it to cure fully according to the product's instructions. Once cured, sand the repaired areas smooth and flush with the surrounding wood.