When we began restoring a '66 Mustang, glass replacement was the farthest thing from our minds. As a rule, we've always opted for the best used glass we could find. Original Ford Carlite glass is the best option when it can be found and salvaged for restoration use. Finding good Sun-X tinted Carlite glass for this Mustang project was anything but simple-the glass we found wasn't in show condition. Qualified glass shop talent can polish out minor scratches, but deep ones can't be removed. What's more, delaminated (fogged) windshields can't be saved.
To understand what you're going to need for your classic Mustang, you have to understand automotive window glass. There's only a handful of manufacturers remaining.
Ford's Carlite glass division has been making automotive glass for more than 80 years. The name first appeared in 1959 when it became an integral part of Ford's Parts & Services Group. That's when "Car Lite" was stamped on all Ford vehicles; it soon became one word. During the '90s, it shared space with Ford's oval logo on most factory-installed glass. When you purchase Carlite glass for your classic Mustang, you can see either or both logos.
In 2000, Ford's Carlite glass division was combined with other parts divisions to become Visteon Corpora-tion, a Ford Motor Company parts spin-off company. A year ago, the two companies agreed to transfer 23 former Visteon operations into a limited-liability holding company known as Automotive Component Holdings. This more or less got Ford out of the parts manufacturing business so it could shop for competitively priced components for new vehicles and its parts pipeline.
Carlite retains sole authorization for distribution of original equipment parts for Ford dealers and auto glass professionals. The brand is still the best choice for your vintage-Mustang glass needs.
The glass can be ordered and purchased from virtually any Carlite dealer in the United States, including your Ford dealer. For classic Mustangs, it gets trickier. The windshields remain available for '65-'70 Mustangs in all body styles. For '71-'73s, only hardtop and convertible glass is available. Carlite was investigating tempered glass for all classic Mustangs at press time.
Pittsburgh Plate Glass (PPG) has been producing glass for more than 100 years. As you might imagine, the company is a huge producer of automotive glass, including laminated and tempered glass for vintage Mustangs.
Our new Carlite windshield...
Our new Carlite windshield from Muscle City Glass was manufactured in Mexico.
When we contacted Barry Hawks at Muscle City Glass in Apollo Beach, Florida, we learned a lot about what's available for classic Mustangs. Barry opened his business out of shear frustration when searching for glass for his '64 1/2 Mustang convertible. Properly marked and date-coded genuine Carlite glass is available from Muscle City Glass. In fact, a complete '65-'68 Mustang hardtop glass package is available for $999, plus shipping and handling. N.O.S. glass is also available when found. Expect to spend more for N.O.S. Carlite glass, etching, and date coding. The average price for new date-coded glass for your classic Mustang is $1,200 for the entire car. Fastbacks may cost more; convertibles may cost less.
If you're going to have your glass date-coded, be very specific about where you want the Carlite logo and date coding positioned. If you don't, it could wind up anywhere.
Because Barry wants his customers to be happy with their glass purchase, he needs to know about the restoration and what's expected. Customers can't simply place an order and expect genuine Carlite glass. They must be very specific about the kind desired: clear or tinted, Carlite or another brand, and whether or not it should be date-coded.
Quality and fit are exceptional,...
Quality and fit are exceptional, as you would expect from Ford's own glass operation.
The current Carlite logo isn't...
The current Carlite logo isn't the same as it was for '65-'66. If you want that, tell Muscle City Glass. The company can either search for a N.O.S. Carlite windshield or have a no-name windshield custom-etched and date-coded.
Windshield thickness isn't...
Windshield thickness isn't what it was 40 years ago. You can actually hear sounds through a Carlite windshield today that you couldn't hear then. This windshield is laminated safety glass, which is PVB plastic polymer sandwiched between two layers of glass.
Side and rear-window glass...
Side and rear-window glass is tempered plate glass designed to break into small, harmless pieces. Our backlight for this project is a PPG Herculite tinted piece. We could've easily gotten a Carlite backlight for this effort.
Backlight thickness, as well...
Backlight thickness, as well as side-glass thickness, appears to be the same as original equipment.
For this article, we asked...
For this article, we asked Muscle City Glass for the "Car Lite" logo on date-coded side glass to see for ourselves. Our side glass came from Argentina.
When ordering date-coded glass,...
When ordering date-coded glass, be very specific about where you want the "Car Lite" logo. Our side glass arrived with inconsistencies in logo positioning because we failed to specify where we wanted them.
Windshield/Backlight Installation
One of the biggest complaints we receive from readers is windshield and backlight leakage. In nearly 30 years of publishing, we've spoken with with all kinds of glass installation professionals and restorers. One common denominator holds true: None of them can guarantee your windshield or rear window won't leak. If you own a classic Mustang with a rubber gasket windshield or backlight, count on some kind of leakage. If it doesn't, you're fortunate; if it does, you're not alone.
For windshields and backlights to be leak-free, you need a perfect bond between rubber, sealer, and surface. This takes close examination of all surfaces before installation. Any irregularities must be corrected.
Your Mustang's roof and A-pillar seams aren't perfect. They were spot-welded together at a clip of about 60-75 units an hour at peak production. Each spot-weld depression is a potential leak-and there are dozens of them. Your objective is to minimize these irregularities. If you're doing bodywork and painting-or even replacing a windshield-fill spot-welds with body filler; then sand them smooth before priming and painting. Once you do that, the next obstacle is the reproduction rubber gasket and replacement glass. Neither is perfect. Replacement glass is thinner than original equipment. Reproduction gaskets, similar to original-equipment Ford gaskets, can be irregular, causing leaks. That's why proper use of the correct sealant is so important.
According to the Ford Shop Manual for windshield and back-light replacement, it's messy and frustrating. In 30 years of working with classic Mustangs, we've tried all kinds of approaches. Here's what we learned: Ford suggests sealant between the gasket and glass. This is a good idea because flexible sealant fills in irregularities-just don't use too much.
Between the body and gasket, Ford suggests sealer in the groove. If you do it this way, it gets very messy and doesn't always prevent leakage. Based on our experiences, it's best to install the glass and rubber gasket assembly without using sealer in the outer groove. Also, use soapy water as a gasket lubricant. This allows the gasket to seat smoothly before final sealing. Firmly lean on the glass across its face to seat the gasket.
This is a typical cutaway...
This is a typical cutaway view of a gasket windshield installation. Install clips first, and put a dab of sealant at the base of each clip. Inject sealant into the inner groove before installing the gasket on the glass. Don't overdo it.
Leakage control comes from ensuring a solid wall of sealant between gasket and body. Once the gasket and glass are firmly seated, fill the area between the gasket and body with sealer. Do it in layers-down deep first-then allow it to set; next apply a second layer, also allowing time. Right before you install the window trim, lay down a top layer of sealant, leaving trim clips exposed. If you lay down too much sealant, it gets messy and the trim is hard to install.
How Is Glass Made?
Auto glass is made of sand, soda ash, coal, and other compounds that are mixed and fed into a furnace known as a glass tank. In the furnace, the compounds melt to become a molten mixture. The mix is then charged into a forming chamber known as a float bath. In this chamber, molten glass is cut off from the atmosphere, floating in a bath of molten tin (metal). During this process, glass is stretched to the thickness and width desired, then cooled until solid. It goes through a process of cooling and heating until it reaches the consistency desired. At this stage, the glass is a huge sheet about 700-feet long, ready for cutting and shaping. It's scored where necessary for cutting into a manageable size for automobiles.
Side and backlight pieces are made of tempered plate glass. It's very hard and explosive when broken, shattering into hundreds of pieces. Tempered glass is formed out of the glass-making process when it's molten and ready for forming. Edges are smoothed to make it safe. Holes are drilled where necessary.
Illustrated here is a '65-'68...
Illustrated here is a '65-'68 convertible, which is trimmed differently than a hardtop or fastback. The basics remain the same: Put rubber between the glass and steel.
Beginning in 1969, Ford glues...
Beginning in 1969, Ford glues in windshields. Instead of a rubber gasket, the windshield floats on a strong, flexible adhesive. This is done for ease of manufacturing and safety because the windshield stays during a collision.
Backlights work the same way...
Backlights work the same way as windshields. There's a rubber gasket, glass, and trim clips. It all installs the same way.
Mustang fastback backlights...
Mustang fastback backlights from '65-'70 employ a rubber gasket. Because they lay flat, they're more prone to leakage. Fill the area between the gasket and body with sealant to keep water out.
National Parts Depot provided...
National Parts Depot provided our gaskets, which are better quality than Ford's. Take them out of the packaging and let them lay in the warm sun to make them easier to work with.
You need a perfect surface...
You need a perfect surface for proper sealing. The paint must also be protected. Use 3M's blue masking tape (found at any home improvement store) to protect paint and trim. It employs light adhesive qualities, so it's easy to remove.
Around 1960, automakers began installing laminated windshields in the interest of safety. It's layered-a sandwich of glass with PVB plastic in the middle. During an accident, it starbursts and cracks, but it stays together to prevent injury.
A Word About Sealers
John Sloan at The Eastwood Company set us straight on windshield sealer. There are two basic types-soft and hard. Rubber gasket windshields and backlights call for the soft stuff known as 3M Windo-Weld Resealant (PN 08634), which is the nastiest sealer to work with. It's black and gooey-use it sparingly and watch where it drips. Despite the mess, it seals well and cures to a flexible consistency. It moves with the glass and gasket without cracking and tearing.
For glue-in windshields and tempered side windows, use 3M's Windo-Weld Primerless Super Fast Urethane (PN 08609). Super Fast Urethane is a glue and sealant. When it cures, it bonds like no other. Count on security and sealing with this. Don't use Super Fast Urethane on a rubber gasket windshield or backlight. Use it only where glass is to be glued in place, such as tempered-glass side windows.
Another brand of sealer for rubber gasket windows is R900 from Adcoseal, available from most autobody paint supply stores. It works the same way as 3M's Windo-Weld Resealant. It's nasty but effective if you use it properly.
Side Glass
Wing, side, and quarter-window glass replacement is straightforward once each assembly is removed. Due to space restrictions, we can't go into the step-by-step removal and installation, although we show how each window type is assembled. Quarter-window glass is easy to replace once you get it out. The quarter-window frame is a combination of stainless steel, chrome-plated die-cast metal, and rubber. A flexible gasket provides a cushion between the glass and frame.
These kind of corners can...
These kind of corners can bite you if not perfected. Headliners should be firmly glued into place.
It's a good idea to do a gasket...
It's a good idea to do a gasket test fit first to ascertain proper fit.
Seat the gasket and inspect...
Seat the gasket and inspect it all around, inside and out.
Sparingly inject 3M's Windo-Weld...
Sparingly inject 3M's Windo-Weld Resealant into the inside (glass) groove. This is challenging and mandates a helper. Don't use too much or it will ooze out when the glass is fitted. A thin film of sealant will do.
Lay the glass/gasket assembly...
Lay the glass/gasket assembly in place first. Use a nylon string around the outside groove to pop the lip inside for seating. Believe it or not, this can be done without string. Pop the lip carefully around the perimeter using a small screwdriver. All you need is patience.
Windshield and backlight installation...
Windshield and backlight installation is a team effort with someone outside leaning on the glass and someone inside pulling the string and popping the lip. Again, use soapy water around the perimeter to ease installation.
With moderate pressure outside,...
With moderate pressure outside, pull the string and pop the lip. Sometimes the string can bind, causing frustration. Make sure it has a smooth path.
Although the Ford Shop Manual...
Although the Ford Shop Manual suggests injecting sealant in the outside groove, this makes installation very messy. Seat the glass, then inject sealer deep between gasket and body. Let it settle and cure, which takes at least eight hours.
Add a fresh layer, making...
Add a fresh layer, making sure it flows into all cracks and crevices. Make sure you have a solid bead of sealant between gasket and body. This stuff is fluid and flows nicely.
Each quarter-window consists...
Each quarter-window consists of four basic parts and four screws. Two machine screws and two self-tapping countersunk screws tie the stainless and die-cast together around the rubber and glass.
Our new tempered glass from...
Our new tempered glass from Muscle City Glass is wrapped in rubber first. If it's damaged, check with any local auto glass shop for a suitable replacement.
Once the glass is wrapped...
Once the glass is wrapped in the gasket, use soapy water as a lubricant to get it into the frame. Gently hit the glass with a soft mallet to seat it.
Glass is retained with stainless,...
Glass is retained with stainless, as shown. Two button-head machine screws retain the stainless bottom.
Two self-tapped, countersunk...
Two self-tapped, countersunk common screws retain it at top behind the weatherstrip. Use a mallet to seat the glass and stainless.
Door-side glass goes together...
Door-side glass goes together the same way as quarter-window glass. It's retained with a gasket along its bottom, as well as stainless. Stainless goes around the top and stamped steel is at the bottom. Two countersunk machine screws hold everything together.
Wing-window glass is a simple...
Wing-window glass is a simple pinch fit-also called an interference fit. The glass fits snugly in a stainless steel frame.
You can replace wing-window...
You can replace wing-window glass without taking the door apart. Just open the wing window for access.
Because wing glass is a simple...
Because wing glass is a simple pinch fit, replacement is easy. Gently wedge in a common screwdriver and it pops out. When you install replacement glass, use 3M Windo-Weld Super-Fast Urethane sealer and adhesive (PN 08609). Once this stuff cures, the window glass is secured.