Older homes tend to have door frames or window sills that are rotted. Many believe the entire frame needs to be replaced when in fact, you may be able to salvage the old wood. The following will help you fill and repair the rotted wood.
Remove the piece of rotted wood and cover the area well with plastic in the event of rain or snow buildup.
Place the rotted wood in a warm, dry place.
Allow it to dry for several weeks. At an angle, drill 3/16-inch holes into the rotted wood.
Apply epoxy wood filler into the wood. Dry the wood again for two to three days.
Apply exterior wood filler with a putty knife.
Level the filler to the rest of the wood and dry the filler.
Sand the fixed piece of wood.
Paint or stain the wood.
Allow it to dry again.
Reinstall the fixed piece of wood.