Painting Historic Sashes the Right Way – Tips for a Flawless Finish
Paint isn’t just decorative—it’s the armor that protects your historic windows from sun, rain, and time itself. Done right, it can seal in your hard restoration work and elevate the look of your entire façade. Done wrong? Expect stuck sashes, cracked putty, and a whole lot of scraping in your future.
In this blog, we’ll break down how to paint a historic sash properly—so it looks beautiful, lasts for years, and honors your home’s legacy.
Why the Right Paint Job Matters
Painting is the final and essential step in historic window restoration. A quality paint job:
Protects wood from moisture and UV
Locks in the glazing putty to extend its life
Prevents rot and water intrusion
Enhances the architectural beauty of the window
A bad paint job, on the other hand, can shorten the life of your restoration and compromise operability. (And we don’t just mean painted-shut windows.)
Choose Your Paint Wisely
Primer: Oil-based primers still reign supreme for sealing bare wood—especially on Accoya or Red Grandis repairs.
Topcoat: High-quality acrylic latex works well with primer underneath and offers excellent flexibility and UV resistance.
Color: If you're in a historic district, check your approved palette! Many cities require certain tones for exteriors.
Avoid cheap paint—it won’t hold up, and you’ll be repainting before the decade is out.
The Right Way to Paint a Historic Sash
1. Prep Like a Pro
Scrape any peeling paint (without damaging the sash wood)
Sand feathered edges and wipe clean with a tack cloth
Clean glazing putty with a soft brush (after it has fully cured)
2. Prime Bare Wood & Repairs
Use a high-bonding oil-based primer on old-growth wood or Accoya
Especially important where rot repair epoxy or new wood joins old
3. Seal the Glazing Line
This step is critical. Paint should overlap the putty and just onto the glass by about 1/16–1/8 inch. This keeps moisture out and prevents glazing failure.
4. Paint with the Grain
Use an angled sash brush for control and minimal brush marks
Avoid over-brushing. Let the paint self-level
5. Let It Cure
Drying isn’t curing. Full cure can take days or even a week depending on climate—especially in humid Southern regions like Florida or Georgia.
6. Avoid Painted-Shut Sashes
If you’re painting with windows in place, crack them open slightly during drying
Wax or tape can help preserve operability at key contact points
Pro Tip: Paint in Parts
If you're restoring multiple windows, paint the sashes while removed (if possible), then reinstall. You’ll get better coverage and reduce risk of drips into tracks.
If painting in place, patience and painter’s tape are your best friends.
A Note on Materials: Old Growth vs. Accoya & Red Grandis
Original historic sashes were made with dense, resin-rich old growth pine. Today, we often rebuild deteriorated rails or stiles using:
Accoya: A premium acetylated wood with a 50-year warranty against rot. Extremely dimensionally stable—perfect for humid climates.
Red Grandis: A sustainably harvested hardwood with excellent paint adhesion and weather performance.
Both materials prime and paint beautifully when properly prepped—and are far superior to typical modern pine or vinyl insert options.
Conclusion
Painting is the final polish on a well-restored window. But it’s not just about looking good—it’s about protecting everything underneath. With the right paint, technique, and materials, your historic sashes will shine for years (and decades) to come.
