Tips for Painting Windows
Credit: xlibber via Wikimedia Commons

Windows take a beating over the course of their lifetime so regular window maintenance and care will pay off over the long term. Ultraviolet rays, changes in temperature and moisture take their toll, but one of the ways you can minimize the damage is to perform routine maintenance which includes protecting the interior and exterior surfaces making up the window with paint or stain.

When embarking on any home design project involving painting or staining walls or wood, there are some important steps you need to follow to get a high quality, durable finish.

However because this particular job consists of a lot of delicate surfaces, care must be taken to prepare the area to accept the paint or stain, and to prevent windows being stuck in place after you finish.

So what are some of the best methods to follow if you are planning on painting your windows?

Parts of the Window

There are several intricate and delicate pieces involved when dealing with windows, and depending on the age of the window, the time it takes to prep the area could be simple or substantial.

Most windows have several main parts that include the casing, the ledger, the sashes with the vertical and horizontal bars (called muntins and bars respectively) spanning the glass portion, and the glass itself. Knowing these parts will allow you to talk intelligently about the topic when buying the materials you will need to complete the project.

Head Casing – The piece of wood, metal or plastic at the top of the window, sometimes called a header.

Sash rail – the horizontal pieces of the outer window frame that form the actual sash.

Sash stile -  the vertical pieces of the outer window frame that form the sash.

Upper sash – the actual upper window frame in a double hung window.

Lower sash – the actual lower window frame in a double hung window.

Double-hung window – a window with 2 sashes.

Meeting rail – the rails that overlap each other in the middle of the window.

Muntins – the cross dividers on the window that form the grid pattern.

Jambs – a piece of wood, metal or plastic on the side of windows that guide the window up and down.

Sill – piece of wood, metal or plastic at the bottom of a window.

Before You Begin

There are a few things you need to have around the house before you begin painting or repairing windows before you paint or stain.

  • Blue painter’s tape
  • Cleaning product for glass
  • Wood putty and putty knife
  • Paintable caulk, primer and paint
  • Paint scraping tool
  • Sash or utility knife and sash brush
  • Small prying tool
  • 1 gallon bucket and sponge

Prepping the Surface

Freeing a stuck window

If a window is painted shut before you begin your work, you can break the paint film by scoring the it with a utility knife, or sash knife. If that does not free it up, then place a block of wood against the sash and the jamb, then carefully strike the block with a hammer in the same direction to loosen it.

Clean the surface

Using soap and water, clean the surface (glass and wood) to remove any grease or dirty spots. For stubborn areas, use a TSP cleaner  (Trisodium, phosphate) to remove all debris. Carefully Repairing a Window Sill before StainingCredit: Opensourceremove loose paint with a paint scraper, then sand the wood to blend in the areas you just sanded or cleaned of debris. Be sure to remove any gloss painted areas and blend them in with the other wood. Be careful not to scratch of damage the window pane. After the sanding is complete, wipe the area down with a tack cloth to remove any remaining debris or dust.

Repairing holes or blemishes

If you notice any flaws in the wood in the sash, jambs or header, fill those areas with wood putty, then smooth it out with your finger. If there are any gaps between the wall and window frame, place a line of paintable caulk and run your wet finger down it to smooth it out.


Remove the sashes

For certain types of windows, this step will not be possible. However, if you have this type of window, carefully remove the sashes from the frame using a wide putty knife. This may be an easy process, or more difficult depending on the type and age of the window.Preparing Windows for PaintingCredit: Opensource

If necessary, use a small prying tool to separate the sash, but be prepared to leave them in place if this does not work. Under no circumstances should you use so much force that you damage the frame or sash. Just leave them in place and use blue painter’s tape to avoid getting primer on the glass and wall.

Protect the glass and walls with tape

Place blue painter’s tape around the edges of each window panes to prevent run-off onto the glass, as well as tape the areas around the frame of the window to protect the surrounding wall.

Remove muntins and bars if applicable

If the window has removable , or snap-on, muntins and bars, pop them out before continuing as this will make your job much easier.

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Applying Primer to the Window

How to Prep Windows for Painting
Credit: mjpyro

Now you are ready to prime the window before your final coat. Some people opt to tint their primer first before application. Basically this is simply adding some of the color of your final coat to get the primer to a half-way point. This benefit of this is that it usually allows you to only apply one final coat.

If you were unable to remove the muntins and horizontal bars, that is ok, just follow this order of painting with a sash brush to reduce the incidences of dripping paint.

  1. Vertical muntins
  2. Horizontal bars
  3. Horizontal parts of the sash
  4. Vertical parts of the sash

It is important that you do not paint the sides or the track of the window to keep the sashes from sticking. If you paint the sash while it is in place, lower the upper one and raise the lower one to get to any areas that are inaccessible when the window is closed. As the primer dries, move the window sashes up and down to prevent them from drying shut.

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Applying Final Coat

After the primer coat has dried, now you are ready to apply the final top coat of paint with the sash brush. If you tinted your primer, only one coat should be necessary, so you are almost finished. However, if the primer is still showing through, or you missed a spot around the edges, apply a second coat in the area. Use your best judgment.

Clean up

Before the final coat has completely dried, remove any blue painter’s tape from the glass panes and surrounding areas. This is important because if you wait too long, there is the potential that you will damage the surrounding areas as you pull the tape off with dried paint attached to it.

For any stubborn areas, use a utility knife to score it first along the edges of each pane, then use a window scraper to remove any excess paint

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How to Paint Windows


Many of the same steps will apply if you are staining the wood around the window. It is important to remove all of the residue on the glass and sashes before attempting to prime and paint the area.

Use a sanding block to smooth out any rough spots and close any gaps in the wood with wood putty or paintable caulk. Then prime the area with an appropriate primer before applying the top coat of paint.  This type of maintenance will enhance the look and durability of your windows for years to come. Just be sure to dispose of any leftover paint properly.