[TAKerry]

Anyone install their own windshield? I bought one and have it sitting in the box. A couple of years ago I had a local company that provided a new window and installed for just under $200. I do not believe they are in business anymore. I was told by the auto glass company that I bought the window from that they were not making them currently and the stock was about used up. Therefore once what they had were gone, good luck! Hence the reason I bought one direct. I contacted someone about doing the install only and the quote was over $400. I thought that was a bit high. I am not trying to cheap out and if thats what I have to spend then oh well. But IF its something I can do then I am ready for a challenge. I am a hands on guy, and do more complicated things on a daily basis. But I also know that just because something looks simple doesnt mean it is.

[many birds]

I did the install on my ‘69 firebird using the butyl tape and mother’s detailer squirt bottle. It was wasn’t too difficult. There’s a YouTube video that explains the process pretty well. I know the that some of the 1970’s cars used urethane—I have no experience with that.

[421mike]

Anyone do one on a 61 bubble-top?

[TAKerry]

So I made about 3 phone calls this morning and found a guy that charges $135 to install. As luck would have it, he was in 'my area' and came out and did the job. Lucky I was home today. Took him all of about 15 minutes. After watching him I think I could do the job myself, may not be as neat as what he did though.

[dataway]

Timely topic for me ... I'd like to do mine myself also. I have to do front and rear ... so it could save me some decent money.

[78w72]

i didnt do my front windshield myself but had a local glass guy that does work on the side do it on 3 of my cars & watched on the first 2 & helped on the last one & feel with a helper i could do it myself next time.

these cars didnt use the butyl tape like the older ones, he used the 3M windshield stuff in a caulk tube, cuts a "V" in the outlet & puts a ~1" tall bead around the opening after applying the primer to the channel & glass, then just put it on the cowl supports & gently laid it into place, nothing else was done.

like you said took all of 15 minutes to install & he charged $50 for the first 2 about 10 years ago & $75 for the last one about 5 years ago, im sure its $100 now. that included removal of the old glass which he used a powered knife tool but said before he had that he uses the guitar string trick that i have done a few times removing back glass. the windshield was $100 for the first 2 & $125 for teh more recent one, all with the internal antenna & blueish tint on the top.

i did do the rear myself on a 72 firebird that i used the butyl tape, marked center with masking tape before removal, cleaned up the channel, primed it & the glass & laid back into place with a helper who was the guy painting the car. then went around the edges with the 3M window goup for extra sealing insurance.

had a local glass company do the front windshield on my current daily driver SUV & it was $220 installed including the glass, a larger nationwide glass company quoted $250 & that was coming to my house or other location to do it. glass install should not be very expensive.

[dataway]

What's the deal with the tape and sealant .... can the 3M sealant be used on 60's cars instead of the tape?

Which is better? I lean towards whatever modern cars use since they very rarely seem to leak.

[tjs72lemans]

Two years ago I bought and had the front glass installed by a professional company for $250 on my Lemans. It would've cost me more to buy and ship a windshield to my house. No brainer. I had the old windshield out, but they cleaned the frame up nice and did a great install.

[dataway]

I'm reinstalling the original glass front and back so not as good a deal for me to pay for install.

[64-3Deuces]

Originally Posted by dataway

What's the deal with the tape and sealant .... can the 3M sealant be used on 60's cars instead of the tape?

Which is better? I lean towards whatever modern cars use since they very rarely seem to leak.

An interesting read on GM glass installation from Belden Speed & Engineering White Paper. This was a PDF which was too large to post so I copied, but only the text shows, not the pictures. The complete document somewhere on their website.
GM (Fisher Body) Evolution of Stationary Glass Setting Methods 1963-1973

RUSTREPLACE.COM SEPTEMBER 1, 2021 1

The installation of the fixed glass (windshield and rear window) in the 1964-1972 GM cars is a topic that continues to be controversial to many enthusiasts. The dialogue typically focuses on the use of either Urethane, or Butyl to adhere the glass to the window channels. This document takes no position on which is “best” for the installer, it merely provides the facts as to how Fisher Body installed the glass originally.

From the 1940’s through the early 1960’s the state of the art for installation of the fixed glass at Fisher Body employed a rubber gasket which retained the glass mechanically in the window channel by having a profile that captured both the glass and the “pinch weld” in the window channel1,3.
From the beginning of the automobile business, concern surrounding safety had prompted many developments in glass design. Most, if not all developments were centered on reducing injury from broken glass, or designing windshields that kept people from being ejected from a car in the event of an accident. Safety glass kept getting stronger and more effective, but highway safety data was not showing continued decreases in ejections1.
Focus continued on glass development and crash data and it was found that windshield separation from the vehicle could be a contributing factor in ejection rates. Some argued that bonding of the glass to the windshield frame is where the next level of injury rate reduction could be found. Data was pointing to the gasket installation as an inferior method and adhesive bonding was evaluated. And then something very interesting happened…
The studies done to determine the risk differences between gasket-installed windshields and adhesive installed windshield showed no discernable difference in ejection rates1. It was found that the cost of adhesive bonding was significantly cheaper than the gasket installation process1,6. At this time (very early 1960’s) a variety of adhesives were evaluated; among them Butyl and Polysulfide.

So, in 1963 GM (Fisher Body) began converting from gasket-installed fixed glass to adhesive-installed fixed glass2,3,4,6. The 3 first models to employ this “new” glass setting technology were the Tempest (Pontiac), Special (Buick) and the F-85 (Oldsmobile). The adhesive was referred to as “a synthetic rubber compound”4. In 1964 all of the GM A-Body cars had been converted and in 1965 the full-sized B & C Body platforms were adhesive bonded1. GM (Fisher Body) Evolution of Stationary Glass Setting Methods 1963-1973
RUSTREPLACE.COM SEPTEMBER 1, 2021 2

The adhesive chosen by GM was a Polysulfide compound which was initially a 3-part adhesive (meaning there were 3 components that had to be mixed to be applied)5. It was a catalyzed polymer which is a thermal setting resin that once cured retains its shape and physical properties over a wide temperature range. The supplier of this adhesive was a company called Thiokol who pioneered polysulfide technology and it has generically become know as simply “Thiokol” adhesive.

To install the glass, a foam “dam” tape was applied approximately ¼” from the outer edge of the glass around its perimeter. The tape had a “J” profile that captured the Polysulfide. Its purpose was to retain any squeeze out of the liquid Polysulfide so that it stayed in the window channel and was not visible from either the passenger compartment, or when looking from the outside into the window. It would all be hidden by the window trim once installed and the UV rays from the sun wouldn’t degrade the adhesive.

A bead of the Polysulfide was applied by a pressurized “gun”, glass spacers were installed to set the glass height and the window was installed in its opening and within a few hours the Polysulfide cured. This process was a manual process throughout the 1960’s and early 1970’s.

The Polysulfide technology did evolve, new chemistries emerged to make it a 2-component product as opposed to a 3-component adhesive which greatly reduced the installation complexity as well as cost5. Finally, in 1973 Urethane technology had developed to the point that GM began its conversion from Polysulfide adhesive to Urethane adhesive which it still uses today3. GM (Fisher Body) Evolution of Stationary Glass Setting Methods 1963-1973
RUSTREPLACE.COM SEPTEMBER 1, 2021 3

Today’s cars do not use a “dam” tape to contain the Urethane, nor do they use window trim. Instead, they paint the edge of the glass with a black “frit” which hides the sealant bead as well as protects it from the harmful effects of the UV from the sun.

So why the debate regarding the use of Butyl tape verses Urethane? It’s not easy to understand. It is true that both Ford and Chrysler (as well as VW) used Butyl technology to set some of their fixed glass, but GM never did1. Those who debate this need only to review any of the Fisher Body manuals in their “Stationary Glass” Section (usually section 4). It’s very clear that Butyl is never used – even for repairs.

It is true that Butyl tape is much more convenient and certainly less messy, but it has its draw backs as well and this is why GM chose not to use it. So just what are the drawbacks? Well, there are 2 which are significant.
The first is that the Butyl technology was difficult to “cross link”. Butyl rubber can be “cross linked”, but it was challenging. So, what does “cross linking” mean? Well, the easiest way to understand it is when a plastic or rubber is “cross linked” it becomes cured. Meaning its molecular structure becomes bound. This physically equates to what we call hardening. Now that doesn’t mean it can’t still be soft, but it can’t creep. So, while it can remain soft, it’s no longer pliable. Think about silicone sealer, it remains rubbery after it cures (cross links), but it’s no longer able to be smeared. GM (Fisher Body) Evolution of Stationary Glass Setting Methods 1963-1973

So, what is the problem with Butyl if it can’t harden? Well, it means it can creep and move and when you have a piece of glass that has stainless trim around it, the glass can sink away from the trim causing aesthetic and mechanical problems with the trim. If you are GM, do you want phone calls from angry customers on a hot day in Florida, New Mexico, Arizona, etc.? Likely not. Now, note – Fisher Body did use glass setting blocks, so setting glass in Butyl alone shouldn’t have been an issue in this regard, but setting blocks required a human to place them and humans do make mistakes. Once the Polysulfide cured on the line, the glass height wasn’t going to change and the dam tape was capable of holding the glass up. NOTE: Setting blocks were used by Fisher Body with Polysulfide.

The second issue is one of its shear strength. Butyl has a very low shear strength as compared to Polysulfide and Urethane. This is important when it comes to the strength of the bonded joint. Again, it appears GM took a cautious approach when it came to the bonding decision. But it could also be that you can use a thinner bead of Polysulfide for an equivalent bond. Said another way, your sealing surface would have to be wider and you would need more Butyl to get an equivalent bond to Polysulfide. This means the car would be more expensive.

Some will argue that Butyl will not pass the FMVSS 212 code and that you must use Urethane to set glass. This appears not to be true (at least at the time). Windshields installed by a few auto makers (General Motors was not one of them) with gaskets or Butyl were available until 1979 and did pass the 212 code. Others will say companies like 3M would not expose themselves to the liability and sell Butyl tape to set glass if it was inferior. You don’t need to look too closely on the 3M packaging to see they have absolved themselves from liability for installations where Butyl was not used by the OEM. In the case of GM – they never used Butyl.

So, the Butyl/Urethane debate will continue, but know that your GM car from 1963-1973 had its fixed glass set in Polysulfide (“Thiokol”) and post 1973 (through today) it was set in Urethane. If you chose the Butyl route understand what you’ve got. GM (Fisher Body) Evolution of Stationary Glass

ENDNOTE:
Federal Motor Vehicle Safety Standards – National Highway and Safety Administration
FMVSS 212
The Standard No. 212: Windshield Mounting Scope and Purpose: This standard establishes windshield retention requirements for motor vehicles during crashes. The purpose of this standard is to reduce crash injuries and fatalities by providing for retention of the vehicle windshield during a crash, thereby utilizing fully the penetration-resistance and injury-avoidance properties of the windshield glazing material and preventing the ejection of occupants from the vehicle. Effective for vehicles manufactured after 1/1/1968
FOOTNOTES:
1. “An Evaluation of Windshield Glazing and Installation Methods for Passenger Cars”, February 1985. US Department of Transportation. NHTSA
2. US Patent #3,155,422, “Windshield Mounting”, US Patent Office filed 11/6/2961, granted 11/3/1964
3. Dr. Allen Skidmore AGRR “Industry Insider” Volume 17, Issue 6 Nov/Dec 2015.
4. Fisher Body, “Adhesive Caulked Windshield Installation” manual for Tempest, F-85, Special 1963
5. Julian R Panek, John Philip Cook, “Construction Sealants and Adhesives”, December 1, 1991
6. Popular Mechanics, August 1963

[dataway]

First, thank you very much for going to the effort to post that.

Second .... I think I'm going with Urethane ... even though I tend to be a bit messy with things that come out of tubes.

I imagine OEM trim on a 68 Pontiac will provide some UV protection in the place of paint.

[GtoFM]

For the complete article that 64-3Deuces posted and much more, go to https://www.rustreplace.com/ . Go to Home, upper right (it's hard to see because it blends into the background color), click Technical Tips, choose Downloads and scroll down to find the article.

[Greg Reid]

Urethane is considered to be better than butyl but it is much harder to work with in my experience. The pros heat it to dispense. That is, they have a caddy that heats it in the tube or they use an electric gun that l guess heats it as it dispenses it.
I tried to do an install using it years ago and had a real mess on my hands because I didn't know that it needed to be very warm to flow. I took it to a pro and that's when I saw how they heated it first.
With all that said I have probably installed 8 or 10 front, quarter and rear windows on several cars, using butyl, and have had zero problems.

[dataway]

Hmmmm... so my best might be either pro installation with urethane, or self installation with butyl.

[Greg Reid]

When I tried it, I was using a caulk gun and the urethane was in your standard caulking type cartridge. I literally destroyed two caulking guns. The triggers bent. I finally got it applied and the glass installed but it leaked like a sieve. When I took it to the glass shop for a redo I saw the electric cartridge heater that he had. It held two cartridges and had a light that came on when it reached temperature.
I think you could get the same effect if you placed the cartridge in a pot of very hot water for a while but I've never tried it.

[dataway]

Do you feel it didn't seal because it was too hard or lumpy, or because it was too difficult to apply?

Perusing some Amazon reviews, there appears to be three different 3M products which vary in viscosity. Many reviewers were saying leaving the tube in the sun, slightly heating with a heat gun and it would come out nicely ... also mentioned to make sure the entire foil seal under the nozzle is punched out.

The standard 3M urethane (not fast cure) mentions that it is "medium viscosity" and "easy to extrude" ... which is not mentioned in the fast setting urethanes which only say that a manul 18:1 3M gun can be used.

I'm betting the pros use the fastest setting stuff than can so the customer can get the vehicle back in use. The standard product requires much longer to cure, might not be suitable for "drive-in" or emergency window replacement.

You know what is bizarre ... kids are using this stuff to rebuild all kinds of suspension bushings and engine mounts on their imports. They center the components in situ and just pump in the urethane and let it harden. Some pretty impressive claims about how well it works and how long it lasts in these applications. Quite possibly a similar urethane to what manufacturers are using to make these bushings and mounts.

[mrennie]

I plan to use butyl following these instructions from the Chevelle site:

“Basics of Basics” Window setting
By Brian Martin

First let me say that the information in these instructions was compiled after years of installing and repairing rusty and leaking window pinch welds. I feel that with what I have seen in failed, overly rusty window pinch welds, and where I have seen pinch welds that have remained in good condition gave me a good idea on what works and doesn’t work. The rust found in window pinch welds is many time directly related to how a window was previously set. These instructions I feel give the best seal and long lasting results. Let me say that there are a few different ideas on things, these have worked very well for me. This instruction is starting after any rust repair, primer/paint. That would require MUCH more instructions.

First off get some 3M (or there are other brands) "pinch weld primer." It comes in a little 1/4 pint or so sized can and has a brush attached to the underside of the lid. Remember, you only apply this over a very clean surface. You should have a clean painted or primed pinch weld. The “pinch weld” is the area where the window butyl tape actually sits. If you will notice that is where you will see the spot welds that hold the inner and outer pieces of that area together. These pieces are STRSW (Squeeze Type Resistance Spot Welder) welded and “pinched” together by the welder, hints the name “Pinch weld”.

Before you install the clips be sure they are correct!!! You should start with either new ones or VERY nice old ones. When they are installed the top of the clip should be just a hair below the top of the pinch weld or body surface. I also recommend that you trial fit a piece of the molding to see if it fits correctly. This is time very well spent. If you find later that the clips are wrong, you will REALLY wish you did this trial fit.
You could even set the window in on some rubber blocks and install the moldings to be sure it will all work well.

The Butyl tape will not remain the advertised size when the window smashes it down. So don’t think that the ¼” butyl tape will STAY ¼”. That is why the tape you use is larger than the actual space you will have between the bottom of the glass and the top of the pinch weld surface. ¼” Butyl tape (3M is one brand, there are others) will end up at about 3/16, 5/32 or even down to 1/8”. The 5/16” will end up at about ¼ or 7/32”. The 3/8” will be 5/16 or 9/32”. The butyl tape can be flattened more, if you get it warm enough. So these numbers are an approximate.

After you install the clips brush the pinch weld primer on the bottom of the pinch weld where the butyl tape is going to lay. Brush up around the clips good. The paint gets scratched when you slip the clips on to the studs and this primer will help protect it.

Next you want to set the window in the hole and find what rubber setting blocks you want to use. There are a few that come with the butyl tape kit and you set them different ways to make them higher or lower. Be sure that the window fits evenly all the way around. Run a piece of masking tape from on the glass out onto the body on the sides and the center of the top and bottom. Really only one should be needed but it helps to have more so you helper can see one well too. These tapes are then cut on the edge of the glass so you can remove the window again. Just leave the tape on the window and the body for alignment purposes.

Be sure the window is clean and free of residue of any kind. With it lying on its back, put the butyl tape on the edge of the glass without hanging off. Roll it out and as you go you can pull the paper off it so that way when you come to a corner you can get around it. If the paper is on, you can't get around the corner. But you want the paper on as you are going down the tops and sides to help you get it straight and so you don't touch it. At the point where they meet, run one next to the other and at the point they pass, cut it with a NEW razor blade. Then DON'T touch the tape, using the razor push it, blending it together. Most guys will tell you to make this joint at a certain spot like on the side or at the bottom. I really don’t think it matters as far as leaking, if it is done incorrectly it WILL leak, what does it matter where it leaks? The point is, do it properly and it won’t leak. I like to look at where it will be the least seen. On the sides it is usually seen and looks like hell. I usually make this splice at the bottom, it seems to be the most hidden spot. You can get the butyl tape in ¼”, 5/16” and 3/8” in diameter. I have found that the 5/16” is the most common with ¼” being used in late model cars on the quarter windows. The 3/8” is rarely used and can really get you in trouble. If you set the glass with the 3/8” you may find that it is impossible to install the moldings because the glass is too high!

NOTE! Some of the new (and replacements for older cars) windshields are thinner glass and the 3/8" butyl tape is needed to set the glass. It raises the glass up to make up for this. So, check with a good trial fit first! If you have an original glass DO NOT use 3/8” butyl tape it will raise the window up too high and the moldings will not fit!

Then with your helper set the glass in using the masking tape as a guide. DON'T LET IT TOUCH until you have it where you want it. YOU WON'T HAVE A SECOND CHANCE the butyl tape sticks RIGHT NOW and will not let go. If you have the glass a little over or up or down too much you can move it a LITTLE after the glass is lying in. Before you push on the top of the glass, using a plastic setting tool or even a piece of wood you can wedge it into the pinch weld channel and pry the window over, VERY carefully. At this time it is best to get it warm. If you can get it in the sun and warm up the glass and butyl tape and push on the top of the glass to get a good seal all the way around.

Now comes the real important part, sealing. First let me say that I have done many windows and used NO sealer what so ever. The Butyl tape alone should be sealing enough. But as an added "safety net" I do the following.

I take a plastic "bondo" spreader and cut it to about a half inch in width. I also round the corners with the razor nice and clean. Using a high quality urethane sealant I put a little strip right on the side of the glass edge or on the butyl tape it's self. Using the spreader I spread it down the side of the glass over the butyl tape to the bottom of the pinch weld, forming a seal from the top to the bottom vertically. In other words this sealer is covering the edge of the glass and the butyl tape, THAT IS IT. The sealer goes down to hit the bottom of the pinch weld right where the butyl tape is resting, but that is it. That bottom edge of the sealer where it hits the pinch weld is most critical. Be sure that it IS sealing down at the pinch weld. It should have a nice clean line as it hits the pinch weld. If it pulls up off the pinch weld, it is not a seal. Don’t assume because you have that sealer down in there, that it is sealed. If you put the bead of sealer in there and then spread it with the bondo spreader with pressure against the edge of the glass and butyl tape, it WILL flow down and seal the bottom, you just have to be sure you are doing that. DO NOT PUT THE SEALER ALL OVER THE CLIPS OR FILL THE CHANNEL this is a DEATH sentence to you job. When you are done, you should be able to still remove the clips if you wanted, that is doing the job right, no sloppy sealer all over the place just because the molding will cover it. Every little nook and crannie created by the sloppy sealer is a place where water will gather and sit longer than needed. This is a place for rust to start.

If you do this and you and see the seal has been made from the top edge of the glass down to the bottom, you know it will never leak. When water gets in there, it will be able to evaporate. If you fill the channel with sealant, the water gets in and can't get out!

You now can put the moldings on and off at your leisure. If your molding is giving you trouble and not clicking into place on the clip. You can take a rubber squeegee and place it on top of the molding and then a small block of wood and tap; JUST tap lightly on top and you can get even the most stubborn molding on. But if you trial fit them and didn't put sealant all over them this shouldn't be needed.

If your car has original glass, 5/16" if the windshield is new,3/8 would PROBABLY be needed. But check to be sure.

[mrennie]

Regarding butyl pinch weld primer, it appears 3M does not make it any longer. The only source I could find was CRL.

It is available on Ebay and from a few US vendors.

Edit: sorry the pics are sideways, I posted with with phone.

[TAKerry]

As for pricing.... A few years ago I had a company provide the glass and install for my 77 T/A. The job done in my garage cost $195. I had the original back glass and threw in a $50 tip and they installed that as well. They even attempted to install the trim but the clips were junk.

Fast forward. I was at Hershey and there was a vendor with the correct (somewhat) windshield for $120. I didnt have the ability to carry the large box the 2 miles back to my truck so I passed. When I got home I ordered one to be delivered to my house. Took less than a week to get it but from Minn to MD the shipping was high. The glass with shipping included to my doorstep ended up being almost $400.

The guy that did the install yesterday showed me his pricing on glass. He had multiple sources and could order from anyone of them. About 10 out of 15 suppliers could have them to his shop the next day. Prices for glass alone ranged from $85 to $120, add another $135 for install. No shipping price. I wish I had found him before I bought mine.

I suppose the moral is to look around for local installers, chances are in the long run it will be cheaper to use a pro than DIY.

[TAKerry]

2021-11-01_02-23-32 by Kerry Grubb, on Flickr

Exactly like 78w72 described