If a home run finds its way through one of your windows, count your blessings if it’s an old putty-set window. Not because the insurance will replace it with a new energy-efficient one. Because it’s easy to repair.
1. It’s even easier if you take the window out of its frame. Carefully pry off the inner trim if it’s a fixed or sash window. Unscrew the hinges (or remove hinge pins) if it’s a casement.
2. Wearing gloves, carefully remove the broken glass. If the glass doesn’t want to come out easily, go to step 3, and then remove the glass.
3. Remove the hard, old putty. Use a chisel or paint scraper, being careful not to damage the rabbeted edge of the window or mutton bars. A propane torch will soften the putty, but it can also burn the wood.
4. As you find them, remove and discard the little metal glaziers points with a screwdriver and needle-nose pliers.
5. After you clean all the old putty from the wood, apply wood sealer to the bare wood.
6. While it dries, pick up a piece of glass 1/8″ smaller than the opening’s dimensions. Get some glazier’s points and mastic putty.
7. The putty starts out hard, but knead it awhile, and it’ll soften up. Lay a thin cushion in the rabbet.
8. Lay the piece of glass in place, and fix it with glazier’s points. Push them in as far as they’ll go, so putty will cover them.
9. Knead and roll a long “snake” of putty, and gently press it into the corner where glass meets wood. Then pull a putty knife firmly along the putty, leaving a smooth 45-degree finish.
10. Let dry a week, then paint, sealing with a hairline of paint along the glass.