RESTORE A WOOD WINDOW SASH

When repairs are in order, a steam box, an easel, and two-part epoxy are your best friends. The work is simple, if tedious, but your reward is original window sash that works the way it was designed to and that will last for decades to come.

- BY BEN BRUNICK

Repairs take time Restoring a 100-year-old window sash so it will last another 100 years means removing the old glazing putty and glass, stripping the frame back to bare wood to make any necessary repairs, priming, reinstalling the glass and glazing, and finally, applying a couple of coats of paint. Though no one part of this process takes too long, there is a lot of downtime.

For example, I use a steam box to soften the glazing putty, which allows me to easily remove the glass without breaking it (though I've learned to expect to break about 20% of the glass on a bigger job). The steam will also soften the paint, but don't be tempted to try to scrape it off along with the glazing. The steam will not only soften the glazing and paint, but also the wood itself, making it more susceptible to damage from the scraping tools.

Even if I can manage to remove the softened paint without damaging the wood, the tools will leave the surface fuzzy and in need of a lot of sanding. Too much sanding changes the dimensions of the sash,

TAKE CARE WHEN REMOVING THE SASH

Old, weighted-sash wood windows were built to be easily disassembled and repaired. Knowing how these windows were built (before you start) is helpful, but don't assume parts are universal or interchangeable from one window to the next. Label all the parts so you know where they go to make it easier to reinstall the sash later.

1. PREVENT DENTS Cut any paint or caulk between the interior stop and window frame with a utility knife. Then pry the stop free using a putty knife to protect the frame. If there is a nail near the top miter, cut it with an oscillating multitool before trying to pull out the stop.

2. REMOVE THE CORD The sash cord is easy enough to remove, but it's worth inspecting its condition and, if necessary, replacing it with new sash cord (not rope, which degrades in sunlight).