This story covers the best way to paint interior windows and what to look out for when painting windows in place.
Windows suffer an amazing amount of stress. Every time you open them, you are working against inertia and stressing the joints. What's even more damaging, however, is that windows are exposed to more changes in temperature and humidity than most other parts of the house. Those fluctuations can take their toll on both the structure of the window and its paint, so windows may need to be painted more often than interior doors or other trim.
To get started on the right track, gather all your tools at the window. Remove locks, curtain hooks, and other hardware so you'll have an uninterrupted surface.
If you're painting the windows in place, use care to keep paint from getting between the sash and the stops -- where it can glue the surfaces together. Keep paint off the sash cords also.
Painting windows can take more time than you might think. It's always best to start the job in the morning so you can close the windows at night.
From 1 to 2 hours to paint a 23-inch, 12-light double-hung window, depending on your skills and experience -- more if you are removing the sashes
Sash knife, putty knife, 2-inch sash brush, utility knife, bucket
Painting and masking double-hung window sashes
Clean and repair surfaces
Masking tape and paint
Gently work a stiff putty knife between the interior stops and the jamb. As you pry the stops free, take care not to dent them because you'll reinstall them later. Pull the nails through the back of the stops and save these pieces, or get replacement stops from your home center.
Cut the cords and remove the upper sash. Remove the screw to open the door in the jamb that provides access to the weight pocket. Retrieve the weights so you can insulate the cavity. Replace the access door. If your jambs lack an access panel, leave the weights in place.
Remove the side and top parting stops, using a utility knife to cut the paint between the stop and jamb. You'll discard these stops, so don't worry about damaging them. Grab a stop with pliers and wiggle it out of its channel. Repeat with each stop.
Make an easel from a ladder for easy sash painting. Open a wooden stepladder and lock the hinges. Drive #10x3-inch all-purpose screws into predrilled holes in the center of each leg of the ladder, using a level to keep the screws on the same plane. Set the sash on the screws. This will put the sash at an angle that makes it very comfortable to paint.
If you haven't masked the windows, you'll have to remove the paint from the glass. Wait until the paint has completely dried (usually the next day) and hold a stiff metal straightedge next to the frames and muntins. Score the paint next to the edge of the glass.