Tricks to Repainting a Window Sill

Tackling Peeling Paint

• Chipped or peeling paint is a common problem, especially on exterior windowsills that are exposed to the elements. Painting over chips or peels is unsightly and encourages the new paint to chip or peel. Use a putty knife, paint scraper or similar tool to remove all the loose and flaking pieces. Slip the knife gently under the peeled edges, being careful not to gouge the wood. Use smooth motions to lift and remove the old paint as if you were peeling a piece of fruit. It is not necessary to remove well-adhered old paint.

Prepping the Surface

• Inspect the window sill for cracks, holes or other surface imperfections. Use wood filler or joint compound to patch holes, and let it dry according to the manufacturer’s instructions. With a block sander and fine-grit sandpaper, gently sand the patches until they are smooth. Use the same sander to lightly sand any remaining paint until the sheen is gone. Gently wash away dust and dirt with a lint-free rag dipped in a mild detergent or vinegar solution. Allow the window sill to dry completely.

Priming and Painting

• Use painter’s tape to mask the window glass and along the seam where the window sill meets the wall. If you will not repaint the rest of the window, mask it as well. Use a paintbrush to apply a thin, even coat of primer to the entire window sill. Allow the primer to dry for at least four hours, or overnight if possible. Apply a thin, even layer of paint with a paintbrush. Work evenly from side to side, using the brush to catch any runs or drips. Slightly overlap each brush stroke to prevent lap lines. Paint the entire window sill before taking a break. Allow the paint to dry overnight before adding a second coat. Two thin coats provide much more even coverage than a single thick coat.

Should I Paint the Whole Window?

• It is always best to repaint the whole window frame when repainting the sill. Paint has a tendency to dull and change color slightly over time, so a freshly painted sill will not exactly match a window frame that was painted previously. Painting a window frame is not much more difficult than painting a sill. Simply mask the glass around each pane, as well as the seams where the window meets the wall, with painter’s tape. Use the same techniques as you used on the sill for a smooth, even look.