Painting Interior Wood Trim

Back to Interior Painting Videos

Painting wood window trim (and door trim, which calls for the same techniques) is commonly called for when homeowners have their old, single-pane windows replaced with new energy efficient vinyl or metal windows, and new wood window trim is installed. It’s also needed when a space is remodeled and new windows and doors are added. Painting wood window and door trim is not hard, and you can get great results if you follow these steps.


First, if there is any roughness to the wood, give it a quick going-over with a sanding sponge, then get the dust off with a duster brush or vacuum. Often the new wood windows are smooth, however, so this might not be necessary.

Filling Nail Holes

Next, it’s time to fill the nail holes. A lightweight spackle will work fine for this. The trick is to overfill the holes so that the spackle actually pushes itself back out when it dries, as opposed to shrinking back into the hole and creating a dimple. So push as much spackle as you can into the hole, two or three times. It helps to make a Spackle Ghost when filling a lot of nail holes. See the video above to learn how to make a Spackle Ghost, or watch this short video.

Be precise when filling the nail holes and remove any excess spackle from around the edges of the hole with your finger. This makes for less sanding later, and less chance the excess spackle will show through the finish coat. Once the spackle is dry, sand it with a fine- or medium-grit sanding sponge. Make sure you sand off any excess spackle around the hole. If there’s a dimple after sanding, you didn’t overfill the hole enough, and a second coat of spackle is the only way to get rid of the dimple. Whether you do this depends on how picky you are about the final look.

After sanding, vacuum the dust off the trim with a brush attachment.


Next it’s time to caulk. All the cracks and joints between trim pieces should be caulked to create a solid look in new, painted wood trim. Leaving the cracks un-caulked, in my opinion, detracts from the look of painted wood trim.

Cut the tip off the caulk tube about 1/8-inch back so that you leave only a small hole for the caulk to come out. You want to be VERY precise when caulking new wood windows and avoid leaving any caulk smeared on the new wood. Have a small bucket of water and a rag on hand to wipe away any excess caulk by always running your finger down the caulk bead to work the material into the crack. A wetted Q-tip can help get the caulk out of corners and avoided the “rounded” look—see the video to learn how to do this.

You also need to caulk between the drywall and the edge of the new wood trim. Last thing you want is an ugly crack there. Caulking this crack means you’ll need to come back later and touch up the wall where you smeared caulk, or, better yet, just repaint the wall. You’ll probably need a separate caulking tube with a larger opening cut to fill this gap, which can sometimes be sizable. Give the caulk plenty of time to dry—a day if possible.

Some people might prime the bare wood before caulking, rather than after caulking as I do, and that’s okay, but I personally prefer to caulk first and then prime over it because I find the priming over the top of the caulk prevents the caulk from “shining” through the finish coat.

Note for vinyl windows with wood trim: You do not need to caulk the crack where the wood meets the vinyl window. That will leave unpainted caulk smeared on the vinyl and won’t look good. Unpainted caulk tends to attract dust over time and look dirty. Plus if you are really precise about not getting any caulk on the vinyl, then eventually the material will shrink a small bit and leave a ragged gap. I suppose if you are really concerned about drafts coming through the small gap then you can caulk it, but I believe that if the windows are installed properly and the gaps are sealed properly on the outside, it’s not necessary to caulk the small gap between the wood trim and the vinyl window inside. It looks much cleaner if you just leave it alone.


After the caulk is dry, it’s time to prime the new wood, but first you should do some taping. (Make sure you have a drop cloth below you, of course.) If your entire window is wood, meaning the wood abuts the glass of the window, you have two options: Tape the glass with blue painter’s tape, or freehand this edge and come back later with a razor scraper to remove any paint that got on the glass. Personally I recommend using blue tape. See the video to learn the technique I use to trim the corners and get the tape perfectly placed on the glass. If your new windows are vinyl with wood trim, then use blue tape to tape the vinyl where it meets the wood.

Priming and painting

Okay, now you’re ready to prime. I like oil-base primer, but the fumes are nasty for painting indoors (use a respirator if you do! And vent the room), so a good latex primer will work. It’s easier to clean up, too.

You need to prime the windows using the same brush techniques that you will use to paint them. This is very important! Poor brush technique during priming will show through the finish coat.

So, here’s the brush technique to use when priming and painting the new wood trim: Divide each window into “legs” and tackle one leg at a time, starting with the top leg. I usually start on the inside and work my way out. In the case of all-wood windows this means starting with the edge that meets the glass; in the case of vinyl windows with wood trim this means the edge where the wood meets the vinyl. However, I will often quickly brush the outside 90-degree edge of the trim first so that I don’t mess up the inside face by trying to paint that edge after. So the actual order I paint a leg is this: 1) outside edge 2) inside face 3) edge where wood meets the wall 4) front face. I recommend watching the video to see this demonstrated.

Remember that all brushing of paint is a two-step process: Step one is to “lay the paint on,” meaning you brush a good, thick coat of paint on the entire surface end to end.

Step two is to “lay the paint off,” or smooth it out with a final brush stroke that will give you an even look.

Start each final lay-off stroke at the corner of joint by placing the bristles precisely against the joint, then brushing toward the middle of the leg and gently lifting the brush off. Then place the bristles precisely in the joint at the other end and do another brush stroke toward the middle, gently lifting the brush off. You want these two final strokes to overlap in the middle of the leg so that there are no “start marks” on your wood trim. By always doing your final lay-off strokes toward the middle of each leg like this, you will make your brush strokes magically disappear and won’t have any ugly, streaky “start marks” marring your new wood trim.

Do the whole leg from inside to outside before going on to the next leg.

After you’ve brush on the primer and let it dry, take a fine-grit sanding sponge and run it over the surfaces. Priming usually raises the grain of new wood, and you want to smooth this out before applying your finish coat of paint. However, be very careful to keep the sanding sponge out of the corners where you caulked, because it can cause the caulk to ball up. Just hit the main surfaces lightly with the sponge to make them smooth, then vacuum the dust off with a brush attachment before applying the finish coat.

If you are using white primer and white paint, and you don’t skimp when brushing on either, it’s quite likely you will only need to apply one coat of paint on top of the primer and you’re done. Sometimes a second coat is required, though, to get the best coverage, especially when painting the wood a dark color (although white always looks best, in my opinion).

Use the same brush technique on the second coat as you did the first. If you do the second coat before the first coat cures (30 days approx.) then it’s usually not necessary to lightly sand the first coat, but if the first coat has cured then it’s a good idea to lightly sand with the sanding sponge before applying the second coat.

You could also try the “paint and primer in one” products and possibly get away with less work. I haven’t used those products much and from what I’ve read they are not quite as effective as using a dedicated primer. They also don’t save you that much work if any. This is up to you, however. Talk to the folks at the paint store and see what they think.

Finish up

After the paint is dry, remove the blue tape from the glass or vinyl. If a bridge has formed anywhere, gently score it with the edge of a putty knife before pulling the tape to prevent it from pulling up any paint. Use a razor scraper to remove any paint that got onto the glass. Use a damp rag wrapped around the tip of a putty knife to remove any paint that got onto the vinyl (this comes off easily). Now look at your beautiful new windows because you’re done!

Back to Interior Painting Videos