67heaven and Stepenwolf windshield question

[markiemyster]

Gentlemen,
I've done a search on windshield install and found valuable information from both of you and feel I can do the install this winter with confidence. I bought new trim and clips which I badly needed. But I do have concerns about the gasket from LIC I bought after reading Bob's (stepinwolf) comment about only buy from Corvette Rubber. I'm thinking maybe don't take any chances and just order another from corvette rubber and try to unload the LIC one I bought.

But I do have one question that I didn't see during my search. What is the proceedure for removing the windshield without doing any damage. What actually holds the windshield in. Do I slice the old gasket off and scrape the old compound out. Is the lip on the gasket what holds it in place?
How delicate is the procedure for removing the windshield without breaking it. Is it just normal common sense or is it super fragile.

Thanks, Mark

 

[67HEAVEN]

You got it. After removing all the stainless trim, cut the weatherstrip all the way around. Remove whatever sealer you can. The rest you can clean out after the glass and clips are out.

It may still be difficult to remove, depending on how much of the weatherstrip you cut out. The glass is quite strong, so don't be shy about pushing if from inside while two people hold either end on the outside.

Make sure they're ready for it when it comes loose so then don't drop it on the paint.

Good luck, Mark.

 

[stepinwolf]

This has always worked for me

Mark,

Before removing the trim, use masking tape to mark exactly where the trim pieces fit into each other so that when the time comes to re-assemble, there will be no need for any guess work. Then, and only then, using the correct tool, carefully removed all the trim.

As for the windshield itself, here is the best way I have found to remove it safely, and not break the glass in the process. The preferred method is to use one of those large cutters, with the break-off blades that slide back and forth.

Let the blade protrude about 3 to 4 inches, and while holding it tightly against the glass, insert it between the outer surface of the glass, and the weatherstrip . Then slowly slide the blade completely around the windshield, as many times as needed, applying slight pressure, until you have cut completely through the outer lip of the weatherstrip, and it falls away.

Now VERY CARFULLY push from the inside with your two hands evenly placed across the glass, being careful to see that it comes out evenly from both sides and at the top at the same time. If when pushing, you can sense it not releasing at some point, stop pushing other wise you will sure as héll break it in half.

Extra insurance against breakage can be achieved by running the tip of the blade completely around the perimeter of the windshield, after the initial outer rubber section has been cut away.

As far as the replacement weatherstripping, my initial comment, or intention was not to state that if the rubber was not purchased from Corvette Rubber, that it would not be usable. The comments were made to express my personal experience, however it's also quite feasible to expect that the rubber you bought from LIC would be more then acceptable for your use.

They " LIC " is one of the most knowledgeable people I have had the pleasure of dealing with when it comes to mid-year parts, and I doubt he would sell you any weatherstrip that was sub-standard.

Good luck, and e-me if you have any problems

Stepinwolf

 

[markiemyster]

Thanks Bob and Bob,
One more question. In the search I did I also saw mention of using primer on the glass and frame prior to applying the sealant so everything would stick.
Anyone know the brand name and number of the primer.
Also there was mention of the rope cord. Is that the piece you pull to rap the weatherstrip around the frame or is that another type of sealant instead of the tube that goes in the caulking gun.
If it's the piece you pull to wrap the weatherstrip around the frame does it come with the weatherstrip or do you buy it seperate
Once again Thanks, Mark

 

[stepinwolf]

Removing it is the easy part

Mark,

From your questions, I can see that not only have you not done this type of labour in the past, but have not witnessed it done either. The best recommendation I could make, would be for you to remove the glass, clean everything as best you can, and seek professional help to install, and correctly seal the windshield, along with the windshield opening.

With all due respect for your talents, I have serious doubts that you would ever be able to install the windshield correctly by yourself on your first try.

The proper installation process, along with the various sealing procedures, are much to elaborate for a Forum such as this, not to mention the correct re-installation of the trim. To put it in another prospective, this is not a " try it to see if I can do it type of job ".

I have done this dozens of times, and I still call in one of the old employees of the local glass shops to help me out. Another issue is the glass itself. It is much easier to break during it's installation, then during it's removal.

As far as your questions, to the best of my knowledge here is what you asked for.

1 Rope is used to help glide the inner lip of the weatherstrip into place around the windshield frame. ( a two man job )

2 Primer, or any other finishing product is NEVER used on any glass

3 Sealant is not used to stick, but rather to seal, and it MUST be of the non-hardening type.

4 As far as any primer that may be needed to cover any exposed metal around the windshield opening, you will first need to speak to your body man
in order to make sure it will be compatible with any finishing products that are to be used during painting or touch-ups.

Stepinwolf

 

[firstgear]

.
2 Primer, or any other finishing product is NEVER used on any glass

Stepinwolf

Bob...just a slight clarification....since the advent of urethane adhesive, black and VERY high viscosity (water has a viscosity of 1 centipoise, the stuff they use today has a viscosity somewhere between 7 and 12 million centipoise. When the urethane is applied TODAY by the OEM's they almost always extrude out of a nozzle a trapazoidal profile that because of its high viscosity can hold the shape.

Prior to applying the urethane adhesive, a clear primer is applied to the glass around the glass where the bead is applied, this clear primer "etches" the glass and provides the mechanism for everything to adhesion and meet FMVSS requirements (Federal Motor Vehicle Safety Standards, meaning that if you get in an accident the windshield is not to come out even with you hitting it with your head, OUCH!), that is followed by a plack primer that is there to protect the urethane bead from UV rays. Even though there is a black trim area already in the glass, that does not keep out 100% of the UV rays, the black primer does that. These primers only have a viscosity of 8 to 30 centipoise. these are not typical paint primers but rather highly formulated primers intended only for glass adhesion to a car.

I can't speak to what was done in the 60's....I was just a kid playing sandlot baseball, but I can attest to what they do today and for the past 20 years....the company I work for, I was the engineering manager when we developed the dispensing equipment to be applied automatically.

Up until the early 1990's there was even a black primer applied to the body flange opening over the clear coat paints because of needing to etch the clear coat to obtain good adhesion. We also developed dispensing equipment for that application. This application went away because the material suppliers came out with "primerless" urethane adhesive, but that was only for the body flange (flange that the windshield sits in).

my 2 cents which has nothing to do with what took place in the 60's.....

 

[stepinwolf]

Don't get me wrong !

Herb,

Your preceding response is very complete, and informative, however I was only referring to how windshields are to be correctly installed in the cars of the 60's.

There are way too many misconceptions regarding the use of primer, and urethane adhesive, during the installation of the windshields, and people that don't necessarily have the experience, are under the impression that the use of these products, can be considered in our mid-year Corvettes.

Case in point is a friend, and customer of mine who previously had his windshield installed by one of the local glass shops. They primered parts of the glass, and then used urethane in the weatherstripping, and between the rubber and the outer windshield frame, before re-installing the trim.

Well guess what, during the installation there were areas around the glass, and opening that had not received enough urethane and the car leaked so bad he could no longer wash the car without filling the passenger compartment floor with about 2" of water.

Then to ad insult to injury, a few months later during a cruise, a rock came into contact with the windshield with the expected results. Well I think you can see me coming here Herb, as the use of the urethane, made it impossible for him, ( or anybody else for that matter ) to remove the trim without damaging it. There was so much force needed to extract the sections from the urethane, that none of the pieces of trim were re-usable.

This is basically why I attach so much attention to the fact that no primer is needed or should be used on our glass, and secondly, all sealer MUST be of the non-hardening type.

Too many owners who don't necessarily know the correct procedure, are going to modern glass shops, who sadly are out of touch with the way this was done 40 years ago, along with the products that were used at the time.

Stepinwolf.

PS, I am still waiting for you to send me your personal e-mail address , so that I can get out to you, the assortment of pictures you asked me for. Please forward it directly to me at the following,, robert.pelland@cgocable.ca