Topic: 65-68 Windshield and backlite gaskets sealing?

[gtcs1]

Hi,

I had to replace the headliner, the front glass and both front and rear window gaskets. It is reinstalled now. But both seal are installed dry.

I'm worried it may leak. So I bought some windshield gasket sealer (Window-Weld Resealant Tube).

What do you guys use to seal the gasket?    And how and where is it best applied to do an efficient (and not messy nor overdone) job? I'm a lot concerned about this job. Thanks very much.

[carlite65]

this quoted from another forum.

#1. The Bedding and glazing compund goes in the channel in which the window sits (in the rubber channel). Start with the bottom part of the window channel rubber first. Stick the tube in there and run a nice line (bead) of it all along the bottom, Then insert the glass at the bottom. Work your way up the sides slowly, then do the entire top. This is all done out of the car. The stuff is pliable, so make sure that the gasket and glass are straight and where everything should be. Clean up any excess. You should now have a new gasket surrounding the winshield out of the car.

#2. Get a rope and put it in the outer channel that faces the car, Make sure that the two ends of the rope come out about 2 inches on each side..so you have something to pull it around each side of the winshield. You can have the two ends coming out the top middle of the winshield gasket or the bottom middle. It really does'nt matter, but I have found from doing these, The bottom seems easier to do. Now Seat the glass on top of the Window frame opening and center it as best as possible. Ok, Now comes the good part. Get a buddy and have him apply pressure against the front part of the windshield with one hand on the center of the windshield, and the other hand on the area that your are working on, and you will start pulling the rope from one of the sides. It does not matter which. Work your way around your entire winshield with your buddy while still applying pressure on the outside, and you still pulling one side of the rope in until the rubber lip comes in on the inside of the car. By the time your reach the other side of the windshield, The winshield should start working itself inside the car and finally "pop" in and seat itself.

#3. You're 95% of the way there by now, and the windshield should be entirely seated correctly. Go around the entire windshield and double-check everything with your eyes and your palms....inside and outside.

#4. Once satisfied with the way the glass is seated in the window frame and gasket and installed, It's time to finish things up and seal the outside for good. Go around the entire outside of the windshield gasket, especially near the clips with either bedding compound, or Urethane, It's entirely your choice. Some people like either. Whichever you use, Just use a nice decent bead of each. If you have a hardtop or fastback, I suggest using the bedding compound again. The urethane can cause issues once its dry with the re-installation of some of the chrome trim. Not so on the convertible trim. Wait until dry, and re-install the winshield trim.

#5. You are done. The next step is entirely optional. You can go inside the the car and run a bead around the entire inside of the rubber lip, but this is usually not necessary unless the winshield is leaking for some freakish reason. If you do it right the first time, This is not needed, but stranger things have happened. Wait 3 hours until dry, then have your buddy run a hose with the water slowly going over the windshield while you are inside the car and look for leaks.

Not too bad right?

I should'nt talk too much, because I have to do it on my '66 convertible as soon as the new windshield arrives! I've put in many of these '65-'68 Windshields over the years. '69 thru '73 winshields use an entirely different process since there is no rubber gasket around the winshield being used. I have a perfect procedure for those years as well..

Happy glass installing!

[gtcs1]

Hi Carlite, that's pretty good info.

In my case, the window is already installed. So a bit trickier. The shop who did the install said "it is not necessary and will not leak, the seal is designed to be leakproof"     I should not have accepted that type of install.

In any case, I need to fix it. So for the glass seal interface, I can try to pry the seal lip a bit to inject a bit of sealant? Right? I could just press the lip back in place and the caulking should spread evenly on the outer face of the glass?

For the car body/seal interface, it can be as you quoted. I was wondering if it would have been better to again pry open the seal leg to inject caulking or if just doing the edge as you suggested can be good enough. If I inject, could the butyl glazing affect/damage the headliner material with being in contact with it? (The headliner is wrapped aroung the body and extend on the outside for about 3/8", which almost the depth of the seal channel).

Thanks for your help.

[carlite65]

if it were my car i would pull the glass and start over. never had much luck doing it as you suggested. with no sealer it will leak.

[gtcs1]

Hi,

Agreed for no sealant = no good.

But what about doing it in-situ as I quoted.  The description you did is to do sealant between seal and car body side with the glass installed (so half of the job is done after glass install).

I'm just thinking doing similar on the glass / seal side, inserting the sealant underneath the lip ? See attached sketch.

I'm just concerned to remove these glass....

Thank you very much for your advice

[CharlesTurner]

You can seal the glass with them in place, this is how I've always done it.  Use a wooden paint stick to work the bedding compound down into the gaps and run a bead inside of the weatherstrip and glass edge.  Mineral spirits for clean up.  Wear nitrile gloves!

[gtcs1]

Hi,

What about the body side where there is the headliner in between the seal and the body, is it better just to do like "caulking" (as suggested before) on the edge of the seal, or run it also under the seal like on the glass side. Can that butyl stuff damage the headliner (being kind of tar/petroleum based) if it touches it ?

[Asm109]

If you use the 3m Bedding and glazing compound the headliner will NOT be damaged.

Why?  Because that is the factory materials and method of installation.

[jwc66k]

Way back in the late 1990's, I sent my 66 Hardtop to a local Mustang shop to get a new windshield and replace the gasket on the rear (the car was being prepared for use as a daily driver). I supplied both NOS gaskets and the shop supplied a new windshield. They told me they used 3 tubes of 3M08008 on the front and 2 tubes on the rear. Thge shop owner told me that it did not leak. It still doesn't.
Bottom line - don't skimp, and have a pro do it if possible.
Jim

[1969 Cale II]

Ok, got the glass out, didn't know they had clips holding the stainless on, thought it might be like my 65 Cyclone. Anyways, there is a shitload of sealant under the stainless, is that how Ford did it? If so, what does one use today? It seems like the glass and rubber was out in, then black  sealant went all the way around rubber and then the stainless was but on. What a gooy mess. Headliner came to a fast stop. One of the sleeves that the rods go through was sewn wrong, they sewed the folded edge to the headliner fabric leaving 2 flaps. Special

[J_Speegle]

Likely someone gooped up the area to help or hope it didn't leak. If I understand your description that's allot more than Ford did in most cases. There are sealants that remain somewhat fluid and others that set up like silicon. I've done a number where I never added sealant (my choice) since the car won't likely ever be rained on so choose not to deal with any mess

Going to merge this question with an earlier thread on the subject that was found using the search feature and the words "window sealant" there are others. It should provide you with more ideas and keep like minded questions together

[RoyceP]

You can seal the glass with them in place, this is how I've always done it.  Use a wooden paint stick to work the bedding compound down into the gaps and run a bead inside of the weatherstrip and glass edge.  Mineral spirits for clean up.  Wear nitrile gloves!

This is the way I do it too. I mask off the paint and apply butyl rubber windshield sealant all around the seal then I install the polished stainless. Never had a leak yet and been doing it this way for many decades and many cars. Remove the masking tape when you are done installing the trim, then use wax and grease remover to remove any excess sealant.