In the first video of the Wood Window Repair Video Series you learned how to remove the lower sash without damaging the components. The video specifically addressed the idiosyncrasies of working on a double hung window in a historic home. The second installment of the Michigan State Historic Preservation Office window repair video series goes into greater detail on how to safely remove the upper sash, and what to look for in the process.
Remove the Upper Sash
Scrape away any buildup of paint so you can easily pry down the upper sash. Quite often there is an accumulation of paint that must be carefully removed before the upper sash will move freely. This is particularly true on older homes which may have multiple coats of paint applied over time. Once the sash moves freely, lower it approximately 6 inches to clear the pulleys. At this point you should be able to tip the right-hand side of the sash inward. Be sure you scrape off any buildup of paint before doing so as the sash is likely a tight fit within the frame. With the sash tilted out slightly you should be able to pull it to the right until the left side is also free. Rest the sash on your knee so you can disconnect the rope. Planning ahead; you will need a pair of needle nose pliers or a screwdriver to remove the nail or screw fastener that is holding the rope in place.
Window Repair Video II Remove the Upper Sash
With the upper sash removed you can inspect the integrity of the glazing. Use a putty knife to remove any loose glazing material. You will likely find an abundance of cracks and crevices, all of which are areas where outside air can migrate into your home. Unless the glazing is in perfect condition, which is highly unlikely, you should remove it completely. You can easily remove the loose glazing with a putty knife. Remove stubborn glazing with the help of a heat gun. Set the gun at 1100 degrees or less so you don’t vaporize the lead. Remove the metal points that hold the glass in place. Carefully lift the glass up out of the sash. If it doesn’t move freely check to make sure that all the metal points are removed. With the glass removed from the sash you can clean the remaining debris from the glass with the help of a razor blade scrapper.
Remove the Stops
Before you can prepare the window frame for paint you will need to remove the center stop on the opposite side of the window frame. Remove the top stop and the interior trim piece. As we mentioned in the first wood window repair video, you should wet down the trim pieces before removing so that any lead dust does not become airborne.
Strip the Old Paint
Strip the old paint from the window frame. Be sure to wet down the surface if you are simply using a scrapper to remove the old paint. If you are utilizing a heat gun to peel off the old paint, you should use a shop-vac with a HEPA Filter to gather all the loose chips of paint. With all the stops removed and the paint stripped be sure to vacuum the entire area. Use a narrow vacuum attachment to clean out the channels.
Remove the Weights
To make sure that the counter weights move freely you need to remove them and inspect the channel they ride in. The weights are usually hidden behind a weight door. You may need to scrape away a buildup of paint to expose the screws that hold the weight door in place. With the door removed you can slide out the weights so they can be cleaned.