A Hands-on Learning Experience

Window sash constructed in the 18th and 19th century was assembled with mortise and tenon joints using wooden pegs to hold the joints tight. They were made to be taken apart, repaired and put back together easily. Simple, yet ingenious.

We were excited to visit the Henry Hogg Biddle House of Conference House Park recently with Park Director John Kilcullen to have a look at the room we would soon occupy and use for our office and research center. The office space is located on the second-floor of the Biddle House. The room is spacious with tall ceilings, wooden floors, and large, six-over-six sash windows that offer a sweeping view of Satterlee St. and the long entrance driveway. A piece of plywood covered the bottom half of one of these windows. Removal of the plywood revealed three missing panes of glass in the lower sash; two of the remaining three panes were cracked and needed replacement. The Tottenville Historical Society offered to make the necessary repairs.

We found the sash to be unstable and in need of more than replacement glass. Layers upon layers of paint were chipped and peeling. Several glazing bars were caked with old, uneven putty. New glass would never fit snugly. Work soon began to restore the sash and prepare it for the glazier. Peeling paint on the entire frame was lightly scraped and sanded, applying minimal pressure to avoid damaging the age-old wood. The cracked glass was carefully removed along with the hardened putty. Then, while admiring the workmanship of the mortise and tenon joints held together with pegs, a small piece of wood fell to the ground. Joints in these old sash windows were secured with pegs and tightened with wedges, we learned. A missing wedge was determined to be the cause of the loose joints. Where can one find wooden wedges today? The only thing to do was to recreate it.

I always admired the work of skilled carpenters, especially the craftsmanship applied to old doors. Think for a moment about the tools available 100 years ago and the techniques used. The window sash, too, is an example of excellent workmanship. Everything needs to fit perfectly, and, if done right, your product will last a century or more. Could I, with less than amateur knowledge and skills, recreate a 1-1/4” wedge with basic tools and not-so-nimble fingers? I dabbled in working with wood before, and enjoyed it. I decided to give it a try.

Luckily, everything needed was found in my garage: a piece of oak moulding (the wedge was not made of oak but I thought hard wood might last longer), a chisel, a hammer and a clamp. I carefully measured the existing wedge and chipped away at the piece of oak until I had made an (almost) identical one. But the true test came when it was tapped gently into place and the sash was turned upright. The frame (rails and stiles) was solid and tight. I was ecstatic!

The glazier installed 5 new panes of glass. A thin coat of satin enamel paint was brushed on both sides of the rails and stiles and the interior muntins (cross-pieces). The putty (also called glazing compound) was left untouched for ten days to cure. A second coat of paint, this time a semi-gloss enamel, was brushed on all the surfaces. The putty was covered as well and a narrow band of paint (approximately 1/16”) was extended onto the glass to seal the putty edge against the glass to prevent moisture penetration. The unit was now ready to rehang.

Reclaiming. Restoring. Preserving. Whatever you call it, it connects you to the past and gives you a great sense of accomplishment. I thought about the original window maker, probably a local carpenter, inserting the last wedge and then installing the sash more 100 years ago. I bet he enjoyed his work, and was proud of it. I’d like to think he would be happy with the repaired sash….and still proud.

The window repair was the first step in readying second-floor space for the Tottenville Historical Society which we will occupy beginning February 2018. More about that to come!

This Old House: Preserving Them One Window at a Time