As I stripped and sanded the sash, I noticed the wood was weathered and grey. After the paint failed on the exposed sides, the sun continued to bake the windows and water from rain and snow penetrated all the way to the wood. This left the wood deteriorated, ready for fungal attack and eventual failure. To rehabilitate the wood, I used a trick I learned from Jade Mortimer of Heartwood Restoration. It’s something called BLO-Pentine, a mixture of boiled linseed oil (or BLO) and turpentine: BLOP for short. It’s a recipe that’s been suggested in Old-House Journal since the 1970s.
After three coats of BLOP were fully cured, the author hand-sanded the sash with 400-grit sandpaper.
Wendy and Alex Santantonio
Boiled linseed oil is a favorite of woodworkers for its ability to protect unfinished wood. When dealing with dry, sun-damaged wood, however, linseed oil alone sits on the surface, not penetrating into the wood fibers. Combining linseed oil with turpentine at a 1 to 1 ratio provides a delivery mechanism for the oil to penetrate the wood. The wood drinks in the mixture. When the turpentine evaporates, it leaves behind oil, both on the surface and impregnated into the wood. The oil slowly cures, and now the wood has natural protection against the elements. It’s important to use high-quality products for this process. I used boiled linseed oil and crystal-clear balsam turpentine from Sweden from American Rope & Tar. Mix a small amount at a time, stirring and swirling in a mason jar. Liberally apply the mixture with a foam brush. The wood should absorb the BLO-Pentine almost as quickly as you can apply it. I applied three coats, allowing each to dry for at least 12 hours. Once it was fully cured (in a week or so), I lightly sanded it. —A.S.
Step by Step Window Repair
1. Working on an open grid bench so that paint and old grout can fall through, a worker runs a sharp common carbide scraper over a window frame.
2. New lights for an old sash are cut from recycled antique glass, which requires extra care because of irregularities in its makeup.
3. A special glazing hammer is used to gently tap in a tiny glazing point to secure the pane of glass in the sash.
4. New putty must seal the glass to the wood, allowing the window to shed water and prevent leakage.
5. The last step before painting is to create a clean, fluid line with the putty knife, tidying the putty into mitered corners. The putty is allowed to cure for a few days before the window is sent to the painting room.
Shop Tour: Window Woman of New England
“We buy these antique houses because we love antique houses. But once you start taking pieces away from it, you don’t have an antique anymore.” —Alison Hardy, Window Woman of New England
Alison Hardy can eyeball a sash and often identify its age by the thickness and wavy or bubbly characteristics of the glass.
To hear owner Alison Hardy explain it, her Amesbury (Mass.) workshop is actually a hospital for ailing windows. On a bright day, sunlight streams through the many windows at
Window Woman of New England, where 15 artisans scrape, putty, paint, and tap window sashes back into shape and send them into the next century.
Alison Hardy is a strong—make that obsessed—advocate for repairing rather than replacing windows. She’s chairman for the
Window Preservation Alliance, an organization that advocates preserving original windows for their beauty, craftsmanship, and energy efficiency. “Original windows are so much better built than new windows,” says Hardy, noting that almost any window built before 1960 can be restored. “You have something that’s already lasted 100 years. If you invest in a little bit of maintenance, it will last another 100 years.”
Typically, only critical cases end up at the shop. If repair is possible when the Window Woman team arrives on site at a client’s home, remedies are applied right there and then. Broken panes of glass, dysfunctional ropes, and faulty locks often can be addressed at the scene. More complicated problems come back to the workshop—as well as any window that requires paint removal. (On the assumption that lead paint is always present, staffers always use special vacuums and specific equipment.)
Hardy got into the window game by necessity. In 2002, together with her husband, she bought “a disaster of a house,” ca. 1850, with a quirky amalgamation of window styles. “Totally different historical eras were represented,” she says. When she tried to find expert help, she found almost nobody in the field locally. So she experimented, found that she loved the process, and realized that she could fill a niche. In 2003, Window Woman of New England was born: “And we’ve been crazy busy ever since.”
In the shop, Hardy demonstrates a technique for picking paint out of corners.
Repair techniques are the same regardless of a sash’s vintage. Each window has its individual challenges, with the condition of muntins and frame entering into the equation. Such variables result in a range of quoted prices: from $50 to simply fix a pane of antique glass to $2,000 for paint removal, rot repair, and reconstruction. —Written by Tovah Martin
The windows at Olson House, now a museum and famous as the setting of Andrew Wyeth’s painting “Christina’s World,” were recently expertly restored by a team from Bagala Window Works.
Courtesy Bagala Window Works
The Pro Tip: Before removing a sash window, secure the sash cords in place with a thumbtack or tape to prevent them from falling into the weight pocket.
To replace broken or missing glass, you have three options: buy new restoration glass, order antique wavy glass from a dealer, or salvage the glass from an old sash yourself. The Santantonios chose the last option, which is by far the cheapest. When visiting salvage yards, look for a sash window that has panes of glass large enough to trim to the size needed. Alex looks for glass that is either exactly the right size, or 4″ larger, making it easier to cut it to size. Be sure to take
glass cleaner and paper towels with you to the salvage yard, so that you can clean the glass and get a true sense of its appearance.
Be sure to take glass cleaner and paper towels with you to the salvage yard, so that you can clean the glass and get a true sense of its appearance.
Cutting New Glass
The key to cutting new glass is to measure carefully and recheck your measurements before marking and cutting. Alex advises measuring the opening size of the glass needed and deducting /” from the measurement on each side, to allow a little wiggle room for movement and contraction, as well as a possibly imperfect opening.
Measure and mark the glass using a Sharpie, as a point of reference to make the cuts. (It washes off easily afterwards.) Then gently clamp the straightedge just off the line so that the glass cutter can ride the straightedge the whole length of the cut. A sharp cutting wheel is paramount to a successful cut. It’s debatable whether cutting oil is useful or not, but Alex advices he’s always had better luck with cutters that incorporate auto-fed oil as part of the cutting process.
The cutter’s job is simply to score the glass on a line that will give the glass a predictable, clean break line. When scoring the glass, make a single slow pass with even and not-too-hard downward pressure on the scoring wheel. Once the first line is scored, pick up a pair of running pliers, mostly flat but with a very slight flare on either side of the center line; a rubber sleeve covering the end protects the glass. Line the pliers up with your score line, then apply subtle pressure, just enough to start the glass breaking on the line. When it works, you see the glass snap and start to crack along the line.
Glass for Restoration
Sash Hardware & Parts
Samson Rope Cotton sash rope with nylon core
SRS Hardware Pulleys, chains & stackable sash weights; stop bead adjusters Glass Cutting Tools
Oil-fed glass cutter
Glass running pliers