Skip to content

How to paint window frames

Window frames need to be maintained well to able to withstand the elements and to keep the outside of your house looking its best.  This can be a tricky job to do well, so here are some handy hints and tips for you.

Clean and assess first

It may be tempting to leave any cleaning until the end but it’s best to clean your windows, the hinges and the windowsill before you do anything else.  This will ensure a better seal as you won’t get a good one if there is dirt on the glass.

Then scrape off old layers of paint, caulk and any other detritus.  This makes sure you end up with a much neater paint finish.

Use any window washing solution you prefer and a new, single-edge blade to clean old paint and gunk from the glass. Apply the solution, then scrape, to avoid scraping on dry glass. Never scrape dry glass. Grit pushed by the razor can scratch the window.

See full article here…

See original image here…

Please take great care when using blades!  You may also need to replace the glazing around the window panes  as it can loosen and chip away.  Fresh glazing will help keep the windows firmly in place and reduce drafts in the home, see below for more.

If there is any concern about lead in your existing paint, you need to bring in professionals.  This is particularly prevalent in homes built before 1978.


This is an essential step of the prep, to get good adhesion for the primer and paint. Sand down any old paint then lightly sand to remove any bumps and roughen the surface slightly; this helps the paint to stick.

No matter the type of trim, if it’s been painted once before, start with a 150-grit sandpaper to smooth away any edges where that old layer of paint flaked to reveal the bare surface. Then, switch to 220-grit sandpaper to fine-tune the surface. If you’re painting unfinished new trim, use only the 220-grit sandpaper to scuff the trim enough for the paint to adhere.

See full article here…

See original image here…

You need to do this really carefully as it is easy to scratch the glass with sandpaper, especially where it meets the wood parts of the sash.  If you have a power sander, don’t use it along the edge of the glass as it is very likely to scratch it.  A good idea is to protect the glass with masking tape before you start sanding.


Single-pane windows are sealed into window frames with acrylic latex/silicone caulk or window putty, also known as glazing putty, to seal the seams and gaps in the window trim efficiently.

Caulking is used to seal cracks around the window while glazing is a similar product that is used to hold glass in place for windows.

Window putty is easier to work with and to apply neatly. Acrylic latex and silicone caulk are more difficult to apply to form a neat, inconspicuous edge along the glass. Putty is applied, allowed to cure and then the excess is cut cleanly away from the window with a sharp utility knife. If it is cut too close or pulled loose from the frame or window, it will have to be re-caulked. Window putty stays flexible for a long time. It can simply be pushed back into place if a mistake is made.

See full article here…

See original image here…

Apply the putty in small amounts to the edge of the pane.  Make sure you do this at an angle as it will allow any water to run off.  Slow and steady is the key to a smooth finish.

If you do need to re-glaze your windows, it will extend the time of the job by a few weeks as it will need to dry for 7-14 days before you apply primer and then paint.


If the trim has been painted previously you can skip this step, but for unfinished trim you will need to apply a coat of primer before you paint. Oil based is a good choice as it creates a better bond between the paint and wood.

Tape off the glass before priming and painting, but if you’re using a latex-based paint and you have a steady hand, you can probably do without the tape. Just make sure to have a damp rag on hand to wipe off primer that accidently lands on the glass. Or you can wait until the job is done then scrape it off using a razor blade.

See full article here…

See original image here…

Apply one or two coats of primer to the window trim and allow it to dry thoroughly between coats and afterwards, the drying time will be noted on the tin.


Choose a day to paint that is dry but not too hot for optimum results, so the paint has time to dry and adhere to the walls.  Bear in mind the humidity as well if you paint during the summer, as high humidity can cause blistering.

There is a wide choice of exterior paint available, from satin to gloss and in a variety of colours.  For the range from Homebase see here, Wickes have an large array, see here, or alternatively Herts Decorators offer an extensive range to choose from to achieve your desired look.

Finally, its time for the exterior paint.  You may need to apply an extra coat if you are changing the paint colour of the trim to get the right coverage. Make sure you allow enough time for the paint to dry completely between coats.

Make sure you are using the right paintbrush; for narrow strips of trim, use a small, angled paintbrush and a flat paintbrush for larger areas.

If you are painting a casement window, paint the frame first and finish with the sill. If you are painting a sash window, paint the bottom frame first. Once it is dry to the touch, move the bottom frame up, move the other frame down, and paint the second one.

See full article here…

See original article here…

Keep the brush loaded with paint and you may want to decant some into a smaller pot (use an old yogurt pot) to make dipping easier.  Then allow the paint to dry thoroughly and remove any tape you have applied, gently at a 45 degree angle.  Carefully remove any paint splatters on the glass with a razor blade, or you can use a special glass razor scraper.

If all this sounds like it requires time and patience you don’t have, you can always get the experts in to ensure you get the perfect finish that will stand the test of time. Herts Decorators provide high quality and professional decorating services to our clients across Hertfordshire, book a free estimate with our team today!

Leave a Reply

Your email address will not be published. Required fields are marked *


George Ryland

Book a free estimate with our team today!