What Is It?
All Lustron windows, whether fixed, awning-type, or casements, were made of lightweight but strong extruded aluminum frames and sashes with double-strength glazing.The single panes of glass are held in the frame by polyvinylchloride (PVC) extrusions that form a seal between the glass and the frame.
The window openings are surrounded by channel sections. The overall units are screwed into the wall of the house.The extrusions fit into the sash, held in place by shallow lips around three sides and a deeper channel on the bottom of each pane of glass.
All Lustrons were provided with fixed window screens. The frames for the screens also are made from aluminum extrusions or rolled aluminum sections, while the screens themselves are constructed from aluminum or bronze wire cloth. Exterior storm windows are aluminum frames with a single pane of glass.
How Does It Work?
The Lustron Corporation installed all windows at the factory. They arrived at the site attached to the metal framing of the exterior walls. There were several types of windows: those with fixed glazing, operable casement style windows, or operable awning-type windows, depending on the Lustron model. The casement and awning window are opened by cast aluminum crank handles on the interior of the lower window frame. They operate a roto-mechanism and metal arm that swings the sash outward.
Screens are attached to the windows on the interior of the frame using small metal screw brackets. Exterior-mounted storm window could be purchased as an accessory. The windows in the living room, dining room, and master bedroom were larger than those of the other bedrooms, the bathroom or the kitchen.For a detailed description of the location, features and the dimensions of Lustron windows, visit the Windows Section in Meet the Lustrons.
Function: Crank handles turn roto-mechanism for casement sash windows, which open out. Cam locks have a rotating piece that connects with the locking mechanism.
Fasteners: Polyvinylchloride extrusions form a seal between the glass and the frame. Window openings are edged with channel sections.
Because the windows were constructed and installed at the factory, they are not directly referenced in the Erection Manual. A brief discussion of the windows can be found in the Master Specifications, Section G, page 8.
The reduced-scale plans for the Westchester 02 Deluxe Model have a few sheets that address window sizes, locations, and installation details:
- Floor Plans and Sections (contains Door and Window schedule) - AP2-B-100 (Provide link to Library, PDF Cabinet, Westchester Deluxe 02 Spec)
- Elevations Exterior - AP2-C-100
- Wall Sections (shows window sections, heads and sills) - AP2-D-100
- Structural Wall Sections - Exterior and Interior - AP2-F-500
- Doors and Window Sash - AP2-H-102
- Joint Seals (shows seals at head and sill of windows) - AP2-H-103
Common Problems and Solutions
Lustron homeowners have a number of typical complaints about their windows, which is not surprising. Every window will experience some problems after fifty years of faithful service. Overall, the Lustron window systems have proven to be remarkably durable and reliable. With repair and on-going maintenance they should last for decades to come. The National Park Service has produced a Preservation Brief on the Repair and Upgrading of Historic Steel Windows, although the Lustron windows were extruded aluminum rather than steel, and the guide is not specific to Lustrons, it still provides useful information and is worth reviewing to supplement the materials in this section.
While it may be tempting to replace the original windows with new insulated or double-pane window units, this will radically alter the appearance and integrity of your Lustron. (photo of Lustron exterior with windows replaced compared to Lustron with original windows) Don’t do it!
There are some relatively easy ways to fix the common problems Lustron owners encounter with their original windows and provide improved energy efficiency, without the expense or damage of associated with complete window replacement.
My windows are cold and drafty.
Seal the Perimeter of Your Windows
This is a common complaint for all metal-framed windows and it has some simple solutions. There are a number of relatively easy steps that can help reduce air infiltration around your windows.
If this has not been done, start by caulking the perimeter of the windows. To do so, begin by thoroughly cleaning the surface around the window to ensure a clean seal, use mineral spirits or denatured alcohol. If necessary use a soft-bristled toothbrush to gently scrub away grime. Next, install a bead of high quality, clear silicone caulk around the entire perimeter, taking care to remove any sealant from the surface of the adjacent panels. Caulking the perimeter of the window should eliminate not only air infiltration into the interior of the house, but also prevent moisture that could damage the steel framing system inside the walls.
Check the Rubber GasketsCheck the rubber gasketing that holds each pane of glass in the window frame. Over time the rubber gaskets that hold the windows may have contracted, creating gaps at the corners where they no longer meet. If the gaskets have contracted significantly, or are showing signs of deterioration, the panes of glass may no longer be snug in the frame. If this is the case, you may need to remove and replace them. Mark each piece of glass with a china maker to indicate its original position in each window frame. Make a simple drawing of your window, label each of the panes of glass and use the china marker to “key” each piece of glass to the drawing. Remove the gaskets and glass from each window. Remove the gaskets and glass from each window. Once removed, check all glass for any cracks, chips or other damage that might require repair or replacement with new panes. Re-glaze the windows using flexible glazing compound designed for aluminum windows. This is readily available at local home and hardware store.
If the gaskets are in good condition and the gaps at the corner are relatively small, you can fill them with a small amount of silicone sealant. Clean and dry the surface of the glass, then place the small amount of clear silicone sealant at each corner necessary to cover both ends of the rubber gasketing. This should be checked annually and replaced as necessary.
The crank handles for my windows are damaged or missing.The casement windows are opened by a simple gear mechanism. The crank handle turns the gear, which moved an arm located in a track along the bottom of the window leaf. If the window crank gear or track has not been maintained on a regular basis, the opening gears can become increasingly difficult to operate over time. The sliding surface for the arm along the bottom channel must have a clean, straight, smooth surface to prevent the arm from binding. If this is not done, the resulting stress can damage parts of the window unit, including the aluminum handles or the track itself.
Crank Set Maintenance
Routine maintenance can keep this mechanism in good working order and prevent future problems. To maintain your window cranks, follow the steps below.
1. Open your window fully and check the condition of the track on the lower edge.
2. Use a damp cloth or soft toothbrush and window cleaner or alcohol to clean the surface of any accumulated dust, dirt, cobwebs, grease, etc.
3. Once dry, apply a petroleum-based aerosol lubricant to the internal mechanisms, the handle mechanisms, and the surface of the track.
4. Examine these at least once per year, cleaning and applying new lubricant as necessary.
Crank Set Repair
If the handle is in good condition but the mechanism of the internal gear appear to slip when operated, the set screw may need to be tightened. If the set screw is tight, but the handle still slips when operated, you may need to replace the entire unit.
1. Loosen the set screw with a slotted screw driver and remove the handle. You may want to apply some lubrication to the screw before attempting to remove it.
2. Place a small amount of clear-bonding, medium viscosity, general purpose epoxy inside the handle and reinstall the handle.
3. Remove any excess bonding agent on the surface of the handle and tighten the set screw.
Please note that epoxy is permanent. Once you use it to affix the handle, you will not be able to remove the handle again once the epoxy is set.
Crank Set Replacement
If the handle still does not operate properly, you might need to replace the entire mechanism. Over time, some of the arms or gears may have deformed with use or stress. You may be able to locate original parts from salvaged Lustrons, visit Buy/Sell for hints and tips on finding Lustron parts. If salvaged parts are not available, the links below are one possible source for a new left-handed and right-handed casement operator that is a suitable match to the original Lustron operator system. It includes the gear mechanism, the arm and the handle. Select the “mill” finish color to most closely match the original Lustron windows (please note that this information is provided as a courtesy for website users and does not constitute an endorsement of any of the products listed below):
To replace the entire mechanism:
1. Open the window fully.
2. Loosen the four mounting screws that hold the mechanism body to the window frame.
3. Pull toward you gently, which will cause the arm to slide down the channel.
4. Continue until the arm passes through the opening in the bottom of the window sash where the operator was installed. Save the original screws for re-installation.
5. Follow instructions on replacement crank set.
If the gear teeth are in good condition but the handle is stripped, you can find one example of a possible replacement handle here.
To replace the handle:
1. Remove the small set screw that holds it on to the gear mechanism.
2. Remove the screw with a slotted screw driver and slip the handle off the gear.
3. Install the new handle and set screw.
I want to upgrade the thermal efficiency of my windows.
Metal windows tend to conduct heat and cold through and around their frame, rather than through the glass. But there are several options you can consider to help improve the thermal efficiency of your Lustron windows.
Some Lustron owners upgraded their package to include original storm windows, while others may have purchased and installed after-market storm windows. Installing storm windows is a very easy and efficient way to provide a second layer of glazing for additional protection from cold winter weather. This is the recommended approach to increasing the efficiency of your windows, since it will not remove or damage any of the original Lustron materials. If you do not have storms windows on the exterior, check the exterior frame of the window for any mounting hardware. If it exists, you can have your local hardware store fabricate new single-glazed aluminum frame storms to match the hardware and window openings. Ideally these should be a large, single pane of glass in a narrow frame that provides the greatest degree of visibility for the window underneath. If you chose a storm with smaller panes of glass, ensure that the muntins of the storm align with those of the window it is covering. For guidance on what storms would be appropriate for you home, try contacting your SHPO and speaking to one of the historic preservation architects.
If you don’t have existing mounting hardware but would like to install new storm windows, there are several companies on the market offering magnetic frame systems that install on the interior of the windows. To prevent unnecessary damage to the window frames, you should require the installer to use double-sided adhesive for the mounting frames rather than metal screws. Once the frames are installed the interior storm windows simply attach via a magnet connection.
If you would like to learn more about magnetic storm window systems, there are several manufacturers with information on their websites. Here are just a few of the links that you might want to explore as you determine whether this system is right for your Lustron(please note that this information is provided as a courtesy for website users and does not constitute an endorsement of any of the products listed below):
- EnergySavrtm Window Inserts
- Re-view-The Complete Restoration of Historic Windows
- Allied Windows, Custom “Invisible” Storms
- Thermo-Press Corporation Interior Storm Windows
- If you would prefer to attempt this project yourself, Window Savers are Plexiglas-based interior storm windows that come to you in easy-to-build kits.
Re-glazing Your Windows
A final option would be to re-glaze your existing windows frames with thermal pane (sealed double-pane) glass. This option will not reduce the thermal conduction (transfer of heat/cold) through the metal frames, but it could improve the overall performance of the windows without compromising their appearance or integrity. Removing the single pane glass and installing new double pane unit will reduce the conduction through the glass itself and the overall amount of surface that easily conducts the cold, similar to the addition of a second layer in the form of a storm window. A local glass company can order custom size pieces of double pane glass of the size and quantity that you desire. This could be a large and complex project. If you do not have any experience with window glazing, you may want to hire a professional to undertake this project, as you will need to size and order new glazing panels to fit each window panel.
My Windows have Been Replaced
If your original Lustron windows have been replaced and you are considering having custom metal windows built to replicate the originals, contact your SHPO to find out if your state has a historic homeowners tax-credit which could be used to help offset the cost of the project. Gather relevant pages of the erection manual and pictures. Contact other Lustron owners via the Lustron Lounge to see if you can find Lustron windows that an owner has made available for salvage. There are several companies that now make historic metal windows, the Old House Journal Web maintains a list of companies that manufacture metal windows on their Web site.