Painting a Window Sash

Lately, I have been enjoying vlogging. For all of the window restoration tutorials, it feels like a video is the best way to describe how to complete the work. I know that watching DIY videos isn’t everyone’s cup of tea, so I’ll include the basic steps below as well. Painting a window sash isn’t complicated, but to achieve the best outcome, there are a few helpful things to know.

You may watch the video below or directly on YouTube.

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Andy has been teasing me about just how real my workshop is. Maybe it’s a little too real? I admit that seeing it in the background of the videos makes me want to declutter and tidy. The supplies and tools are getting a little out of hand. Also, pay no attention to those asbestos-covered ducts.

Sash Painting Steps

Before painting a window sash, it should be primed, and the fresh glazing putty should be cured (skinned over) for the proper amount of time.

Clean the Glass

• Before you paint, give the glass a quick clean to remove any stray blobs (very technical term!) of dried putty. I like to use a retractable utility knife/box cutter and an inexpensive scraper with a handle.

• Wipe the bits away with a dry cloth.

At this stage of the sash restoration, the putty has cured, but it is still vulnerable to gouges with the blades or compression marks from your fingers. Work gently.

Paint the Glazing Putty

• Begin painting the window sash right on the glazing putty. (You do not need to prime the putty.) Your paint should slightly overlap the putty and spread right onto the glass. Overlapping onto the glass seals out any moisture, so it does not seep behind the putty.

Please note that the sash below has been heavily used for teaching purposes, and it’s …rough.

After some practice, glazing putty will look tidier like the photo below.

That said, don’t be too hard on yourself if your work doesn’t look as perfect as you would like. Chances are, no one else will even notice. The window I used for this post and the video will be tucked out of the way in BHH, and it is not at eye level. Also, the storm window will obscure most of the flaws.

Doing high-quality work is important, but so is learning. If you are just starting out, begin with a low stakes window from an out-of-the-way location if you can.

Remove Stray Paint

• If your paint line on the glass goes overboard like mine did below, it’s easy to remove the extra with the scrapers. When the paint is dry, cut the line with the retractable blade and a straightedge (optional), and use the handled scraper to remove the excess.

Avoid

• Do not paint the sides of the sash or any other points of friction. If you aren’t paying attention, and you accidentally paint there (I’ve done it!), just sand the area with 120-grit when it’s dry. There’s no need to spend time removing the paint. Glossiness is what causes a sticky sash at the friction points. The sandpaper will knock down the sheen.

Repeat the Steps

• I use two coats of paint on each side of the sash, sanding lightly between coats. Touch up as needed.

Allow the Paint to Cure

• Different paint formulas require different cure times. Although most paint is dry to the touch within hours, the full cure can take up to as long as two weeks–especially if the humidity is high or the temps are cool.

Let me know if any of these instructions are unclear or if you have any comments about the video. I am looking forward to popping this window back in its proper place. This one has suffered through the longest window restoration ever, and I am tired of looking at it.

I am ready to work on one of these fancies instead.

Painting on of those window sashes is way more fun.

If you are looking for more window restoration posts and videos, you’ll find them here.