VARIOUS WINDOW RESTORATION DETAILS
I began my restoration career in Texas in 1985 after a number of years in new home construction and remodeling. Unless you consider my demolition of the Bremond Building on Austin's Sixth Street 'restoration.' Apparently I do, if you read a few posts back.
And though I had a lot experience in many types of building repair, I was an absolute neophyte when offered my first job doing a 'spruce up' to a 1930s house in Little Rock, Arkansas. This led to many real restoration jobs, but boy, did I suck at glazing windows when I started. Usually done from ladders, I'd chip out loose hardened putty and replace it with Dap 33, then the industry standard putty. I'd roll little cylinders that looked like long, skinny joints and press them into the unprimed putty rails, then mash them and run my finger along the putty run.
I was terrible. But I asked my brother, a stained-glass artist and glassmaster, how to do it, and he set me straight. It still took me years to master the art of restoring windows, but I finally got it down after many attempts. I continued to learn Old Window Repair as an art.
Opening my first Restoration shop in '97, I got my window legs. By the mid 2000oughts, I'd gotten pretty good at puttying (one of the hardest things to learn), and in the early 20teens I moved to Connecticut and went to work on Colonial-era windows. Colonial windows are both a curse and blessing compared to what I worked on in Arkansas. Their wood components are much thinner, and the muntins (crossbars between glass) are far spindlier. The glass, being older, was much more difficult to match and cut for replacement, and the thinner glass was harder to set properly.
But the Victorian and Craftsman styles in Arkansas feature huge panes up to 40 inches across. Beautifully figured, wavy with streaks and bubbles, it was hard to remove or reset without cracking it. The panes from New England were certainly easier to handle unless they have Crown glass.
That stuff will test you, and test you but GOOD.
More on that later in the post.
BUT READ ON!!
As my techniques and technologies advanced, I became quite proficient indeed. I've worked in several glass shops doing only antique windows and have nothing but praise for those who do the same. It's beyond craft; it's art.
Here are some pictures from a glass shop I helped to build for a large restoration company in North Stonington, Connecticut. The stripping room was already there, but it needed a lot of tweaking to make it productive, safe, and efficient.
For you not versed in restoring antique windows, there are essentially four stages: stripping, repair and wood prep, puttying, and painting. There are mini-steps between all of these steps, so don't get picky, you window freaks. You know: priming, sanding, cleaning and cutting glass, that kind of stuff.
Here are some random pics from that shop, in no particular order and missing the repair stage. That'll come later, as will many other posts about Antique Window Repair.
While still outfitting the strip shop, I was given a number of windows to strip and restore, mostly to test the equipment, estimate time spent on each sash, and develop proper shop ergonomics. Stripping windows is dangerous, hard work, and without the proper protective equipment and air handling, it can be dangerous to others nearby. Virtually ALL antique windows have lead paint on them, and we went to a lot of expense and trouble to alleviate any dust or leavings. You'll see how the shop progressed through this post.
The above sash was one of the first in a job of 436 sashes from the oldest building on the Yale Campus, Connecticut Hall, built in the mid 1750s. After stripping and sanding, there was still some paint attached to the old white pine rails and stiles, the main structure of the window sash. This was likely lead paint or possibly milk paint, and we've discovered that this stuff, when deeply imbedded in the wood grain, is nearly impossible to remove without gouging the wood. In that case, we encapsulate it with primer and paint. But if it flakes, it goes.
Yale's Connecticut Hall before restoration
Typical condition of the windows. Note the deteriorated putty rails (in the crossbars known as muntins), extreme paint peeling, and hundreds of years of putty over putty over.. you get the picture.
EEEwww,,,,, is what we window restorationists would say. Then we'd say, "Let me show you what I can do..."
Back to the stripping shop as it was created.
The sash in the second picture above has a strip of wood installed between the stiles of the sash, as did many of the others. Though many windows have such treatment because of deterioration of the bottom rail over time, this strip went between the stiles, which proves that it was designed that way. We've puzzled about this for some time, and I'm still not sure the answer. Anyone have an explanation? Only a handful of the 430 odd sashes had this feature. It's obvious that this is an original design by examining the end of the stile; it extends the same width beyond the rail as the width of the strip.
Needles to say, during repair I removed it, cleaned out the old paint, then primed all joined surfaces before reinstalling it with glue and clamps.
Many small divots, dings, and chips were repaired, either with glued-up wood (Dutch repair), wood fillers (Abatron products are my favorite, though I sometimes use Durham's Water Putty in my own shop), or one of my favorite fast-drying compounds, MH Ready-Patch. These companies don't pay me, I really like their products.
Here an original wood dowel can be seen keeping a muntin in place. Many people mistakenly believe that window sashes such as these are supposed to be straightened, squared, and glued up. Not true for the gluing part. Most wood sashes are kept in position by the glass and putty, and MEANT to move a tiny bit with weather changes, especially the thinner Colonial sashes. It has to do with differential heating and cooling of the wood and glass; a fixed window, glued into a specific position, will expand with moisture and can break glass, a very high-priced commodity in the Colonies. Better to have the putty loosen and add new putty than find new glass. And once you've properly restored a Colonial window, you'll see just how strong the window holds its shape.
Sash stripped and sanded.
Detail of wood strip added (before removal and reinstallation).
The glass, before removal, was numbered with a black Sharpie, then carefully cleaned of hardened putty with a razor (and prayers it wouldn't break while you did it), then washed in a white vinegar/water solution to clean them. We built these slotted cases to allow them to dry quickly so they could be reinstalled quickly.
Hey, we had 435 sashes to completely restore while the Yalies were off for summer break. This included taking them out, restoring the window casements (the frames and trim that hold the windows and cannot be removed), and reinstallation of the restored sashes.
YOU try it. We did it in less time than we had bid, and were the only company on that project that came in under the time allotted.
Actually, except for the few square sashes already presented here, these particular pieces were part of the Test Windows, and some came from other properties. The Yale windows had no curves.
Always prime before caulking.
Didn't know that, eh? Well, do it.
This sash was part of a complete window set, with frame, casement, and trim pulled intact from a soon-to-be demolished building . I remember removing the glass and prepping the sash and frame, but I don't recall restoring it completely. We often did something that we finished later or used as sample windows, and I believe that when the Yale job began in earnest, this sample got put away as we dove into Yale headfirst.
One of the interesting things about the sash in this ornate horizontal window was that the interior paint scraped off completely, turning to powder as I ran my scrapers over its interior surface. This was only true on the interior; I imagine that it was a window that either received a lot of sunlight or a basement window near a heat source, such as a furnace. That would crystallize the paint right well.
It seems like a rather ornate window for a basement, but as you'll see in the next pics, the frame looks baement-ish.
Sash completely stripped and frame brought to whatever first coated it. Almost looks like a stain, but I assume it's the original paint's pigment (likely manganese dioxide) that colored it black.
Note the heavy sill; still looks basementish to me. Too ornate for a Classical revival upper story half-window.
This is the interior, showing the perfectly clean sash, which wasn't steamed or stripped without using more than custom-ground scrapers and a few abrasives. But only on the inside. The outer surface had the imbedded black paint.
Here is another window sash that was done in the middle of setting up the Strip Shop. At this time, we hadn't yet built the glazing and painting shop; it was just me, as the new window crew was still a month or two away. Note the white powder on the diamond-shaped pane to the right. No it's not my midday snort! That happens much, much earlier.
No it doesn't!
It's the calcium carbonate (whiting) that we use to clean the putty haze from the newly-installed glass.
Glass panes are installed after priming, and are backbedded in small runs of glazing putty, which keeps them waterproof, strengthens them, and keeps them from rattling. So when they are set (squished into the putty rails), they exude a bit of putty and once removed, that putty leaves a haze that can be cleaned by brushing CaCo2 onto the haze using a china bristle brush. The same is done on the exterior side, only it is worked with a putty knife before cleaning with CaCO2.
SEE HOW SIMPLE IT IS?????!!!
Yeah, me neither.
Damn, I HATE to leave my coke around the shop! Okay, that joke was old yesterday.
CaCO2, calcium carbonate, is essentially ground up limestone. It's chalk. It is good for absorbing things. We had so many windows to do on the Yale job that we ran the local paint and hardware stores out of the little 1-lb. CaCO2 boxes, mostly from the Rainbow company, which makes many fine old-time compounds useful to the Restoration-minded. Many of their products can be found at Montville Hardware, the Greatest Hardware Store on Earth.
I am not kidding. If they don't have it, it doesn't exist.
One day, bereft of our precious whiting, we fretted for a bit then realized we could substitute a product we already had on hand, Setting-Type Joint Compound. It comes in 20-lb. bags, is a hell of a lot cheaper than whiting, and does the exact same thing. Sprinkle some on the putty haze, brush it very carefully to the edge of the putty, and your haze is gone. If you wait too long, the haze dries and you must scrape it with a razor, which is time consuming and might nick the seal you made when you worked the putty.
Sash clean and ready for putty. At least the middle seven panes are.
Here is how the stripping process begins.
This pic was taken from Steve Marshall's glass shop, another of those in which I toiled. Steve does a lot of antique woodworking restoration, but windows are his bread and butter, and he's very good at it. I used his shop in this pic because once I got going at the North Stonington Yale job, I had no time to breathe, much less shoot a lot of pictures.
The sash is put into a steam chamber, which heats the wood and softens the putty and paint. Once softened, the window is taken out and quickly stripped of the putty, taking care not to scratch the or break the glass. Softened paint is also removed if it isn't imbedded in the wood grain.
The process often takes two or three sessions in the steamer, as the putty will re-harden as you remove it. Then back it goes for a few more minutes before the scraping starts again. Special scrapers made of hardened steel are necessary, as are razor knives, chisels and brushes. The small metal points that hold the panes in the wood sash have to be found and carefully removed, otherwise you'll do the achy-breaky dance and say bad words when you hear the crack.
All this is done in a room with "negative air," which means fresh air can come in, but any air going out has to go through an elaborate filtration system to make the dust stay in the 'contamination area.' And does it contaminate? You bet it does. The steaming keeps most of the flakes, chunks and powder wet, so little becomes airborne, but as the sash dries, lead dust can float a bit. Wear a respirator, gloves, and a 'hazmat' suit anyway. If you're not trained and tested for lead regularly, DON'T DO IT!
Paint often comes off too, a positive freebie!
Some folks like to scrape their wood sashes to raw wood immediately after steaming, but most wait until the sash dries. Scraping wood while wet often strips out wood fibers and gouges the soft pine, the wood from which most antique windows are made. Drying also crystallizes the leftover paint, which makes it easier to remove.
This sash is being scraped. Note the blocks and wedges around the stiles and rails; this holds the window in place and allows the sash to be turned by tapping out the wedges Very sharp scrapers are used here, an care must be taken not to gouge the wood while exposing the fine detail of the muntin interiors. It's very satisfying to see ten layers of paint come off to reveal the crisp lines of a milled surface; often these lines are so muddy from thick layers of paint that they are invisible. Don't believe me? Take look at your old windows' muntin interiors. Sharp edges and fine detail are likely filled, rounded, and hard to see.
Back to North Stonington.
The crew at work in the stripping shop. All wear 'hazmat' suits, specialized respirators, and gloves during the initial stripping. Once the dry sanding and scraping occurs, the hoods and shoe coverings are added. And even at this stage, body vacuuming and clothes changing is required upon leaving the contamination area. The steamer, built into the wall, can be seen to the right, and strong plastic grids underlie the sashes on the table. Beneath those, heavy-duty plastic bags inside the OSB boxes catch the steamed paint and putty. These bags are removed, tied and wrapped, and set to a lead relocation facility, where they are given new identities and a house in the Nevada desert.
In actuality, each state's Department of Environmental Health (DEEP in Connecticut) has its own guidelines for lead paint disposal.
Terry uses a sharp scraper to remove the stubborn putty. Other scrapers scatter the table. Where are your gloves, Terry? He put them on when I reminded him. The vacuum in the foreground is essential for cleaning the sashes during scraping, and is set up with HEPA filters and collection bags. The doors in the background are left closed but are not sealed; this allows enough fresh air in to keep the crew alive as well as create a jet of air that is sucked into the massive air filtration system on the other side of the room. If you stand by these doors, you can feel the air being sucked by you. The system is cleaned daily and tested monthly.
This sash, not from Yale, shows the three stages of puttying.
The closest panes have been puttied and worked smooth with a putty knife. I like to leave about an eighth of an inch of the putty rail behind the glass exposed; this way, when I paint the putty, I can also paint a tiny line onto the glass, which seals the putty from weather. And because I left the putty line a tiny bit shallow, the paint on the glass can't be seen from the interior.
The next three show my own technique for working the putty onto the panes, pushing it as deep into the putty rail/glass pane joint with my thumb to fill all voids, and doing it repeatedly. Then the smoothing can start.
The panes to the right have been set, backputtied, and dehazed on the interior side. They await putty.
A word about putty.
The Industry Standard for wood windows has been Dap 33, and that since I was in short pants. But I have foregone using this putty for old windows with the discovery of Sarco. The Sarco family has been making their particular putty formulae for many decades, and in my humble opinion, it seems far superior to Dap 33. Dap 33, according to the company's tech sheets, sets up for painting in two weeks, then an oil primer is to be used before coating with exterior acrylic enamel.
But my experience is that 33 is still very soft after two weeks, and even if it skins over (it never did quickly enough with me), it is still completely malleable, allowing fingerprints and distortion of the putty. And if it is still soft, that means it still needs to allow the linseed oils to evaporate while curing. How does it do this when you've sealed it with paint?
To top it off, 33, if left to dry completely, often mildews and will crack from exposure. There is a period of time when the putty hardens enough and doesn't crack or mildew, but not while the sash in in my shop. And my clients can't wait for months without their sashes.
Sarco Type "M" skins over and gets partially hard within four days, allowing for quick shop painting, and the company recommends painting directly with acrylic, not oil primer. If the sash must be installed, then left for another crew to paint in an indeterminate amount of time, Sarco "Dual Glaze" putty is used. This type stays soft and takes longer to cure.
All antique glass (before 1935, by my standards) has distortion that identifies it as such. Streaks, bubbles, waves, and focus distortions are obvious from Craftsman-era glass down to Colonial Crown glass. The older the glass, the more distortion is usually found. Most of the glass in the Yale Connecticut Hall windows was newer than the windows themselves. The building dates from 1750s, and at that time the Colonies had to buy their glass from the Crown (thus the name). That hand-blown glass was often shipped in huge crates from England and used as ballast in wooden square-riggers. The Crown then sold it, laden with heavy taxes, and the Colonists grumbled about such a necessary commodity being so expensive. The fact that the taxes went to support the King Georges' elaborate lifestyles didn't go over too well, either. Add to this that the Colonists were prohibited from making their own glass, and you'd think the sashes from Yale's oldest dormitory would be crawling with Crown glass.
Yet out of thousands of panes, we found only a handful of original pieces. Why?
Well, it was a dormitory, and young Yalies in the late 18th century were probably not that far removed from college males today. It seems possible that through the years, much of the glass would have been broken from use, windows slamming, sashes dropping to the sills (there were no ropes, pulleys or weights to keep the windows open; a small stick was shoved into a slot in the trim to do this), and general falling out from deferred maintenance. Plus the partying. They were Yalies, after all. The building has four stories, so there were a lot of panes worth breaking.
One of the few pieces of Crown glass. Hard to see through, distorted, filled with streaks and bubbles. Also extremely thin an nearly impossible to cut. We treated these panes like wounded birds.
Some comparisons of Crown versus mid-1800s glass. The distortion can be seen easily by looking at the fluorescent light reflections.
Seriously distorted. Lookit them streaks and bubbles.
This is a non-Crown pane, but it shows the 'potato chip' structure that makes a lot of extremely old glass such a challenge to cut (or mount for puttying). Some say it can be cut on a pile of corn starch, but I've yet to master that technique.
So there you have it. Not exactly a primer on how to restore antique windows, but a tiny bit of a taste, and hopefully enough to either pull you into our circle of craftsmen and craftswomen, or to turn you around and direct you to your garden. Gardening is MUCH easier, trust me. It's why we Antique Window restorationfolk are so wealthy.
BWWWWAHH Ha ha ha ha ha..... (wipes eyes). Oh, yeah. That was good.
Some more pictures of Connecticut Hall before and after restoration. Yes, we did the frames and shutters, too, but I was only in charge of sashes.
Before restoration. Our team can be seen at the lower right, putting a plan together.
Yeah, you've seen this, but it bears repeating. Don't let your windows get to this stage.
Paint is not only alligatored, but hides the original coats with tens of layers, one over the other.
I'm very proud to have guided their restoration, but I was only part of a huge team of craftsmen. A Collaboration of Craftsmen.
The outer stop of the upper sash, showing that the upper sash was only to be lowered a small amount to allow air to circulate to the ceiling at night, displacing the warm air that had gathered there during the day. But why such a small amount of sash movement? Anyone know?
This is not an original window!!!
This is a one-piece modern sash!
It was likely that someone inside had this changed out to keep the drafts from freezing them in the New Haven winters. A cheap, but effective trick. My question is, "Where did we get the extra sashes to replace this monstrosity?"
The damned impostor doesn't even OPEN.
AAAUUGHHH! Another one! Kill it quickly!!!
By Autumn, the students reconvened and Connecticut Hall was once again in operation as an office for the university.
You didn't honestly think they were going to put Yalies back into it as a dormitory, did you? After all that work?
The windows are now protected with storm sashes that open, have screens, and admit outside air. And the entire exterior shines without those window-unit air conditioners from the first CT Hall picture.
Made you go back and look, didn't I?
Finished product. And though I understand the need for storm windows, they do remove the three dimensional look of the original sashes.
I LOVE this brickwork. New Haven Bond, I believe.
