[tjs72lemans]

I got a replacement windshield installed, at my house in my 72 Lemans convertible for $300. After watching them, I wouldn't have wanted to do that one myself. I have replaced my 55 Chevy and 80 Fiat spider conv. , and they're all different. If you do it yourself, be mindful of how much seal you put on and how much you press your new glass to the seal for your moldings to fit.

[mrennie]

Originally Posted by crustysarge

I made a mistake and laid the ribbon a little high on the bottom and you can see half of it beyond the stainless molding but so be it, this is not a $100K car.

I am leaning towards using the ribbon when I install my glass. One thing I wonder was if it would work out better to lay the glass on a padded work stand with the interior side up, then apply the ribbon around the edge of the glass. This way you know the ribbon can't be in the wrong spot (too high/too low) when you put the glass into position.


Does this sound like it would work?


Thanks

[MUSLCAH]

These cars had butyl tape from the factory......and that’s what I used in my front and back glass 67 gto. The butyl tape gives you the correct height ,for the the glass....so the moldings fit correct.

[MUSLCAH]

Originally Posted by mrennie

I am leaning towards using the ribbon when I install my glass. One thing I wonder was if it would work out better to lay the glass on a padded work stand with the interior side up, then apply the ribbon around the edge of the glass. This way you know the ribbon can't be in the wrong spot (too high/too low) when you put the glass into position.


Does this sound like it would work?


Thanks

I’ve always put the tape on the channel.....and all the Windsheild guys I’ve had in my shop ovah the last 40+ years ...do it that way.. plus it’s nice to have those pump up suction cups....Incase you have to slide the glass ,one way or the othah..

[brad900]

Originally Posted by MUSLCAH

These cars had butyl tape from the factory......and that’s what I used in my front and back glass 67 gto. The butyl tape gives you the correct height ,for the the glass....so the moldings fit correct.

A 67 GTO never used butyl tape. Look in the Fisher body service manual, only used urethane

[MUSLCAH]

Originally Posted by brad900

A 67 GTO never used butyl tape. Look in the Fisher body service manual, only used urethane

Well they must have run out of urethane that day...cus my ORIGINAL WS ...had butyl .

[TedRamAirII]

The Butyl can keep your spacing correct, and used as a dam to hold the Urethane.

[brad900]

Originally Posted by MUSLCAH

Well they must have run out of urethane that day...cus my ORIGINAL WS ...had butyl .

Here you go

http://www.beldenspeed.com/technical...lation-details

and here you go

Below from John Hinckley. If you don't know who he is, here's a little info. http://www.corvettemuseum.org/librar...hinckley.shtml

John Hinckley: "GM never used butyl tape or anything like it to install windshields or backlites. Period.

The body opening flange was coated with black silane primer using a flow-brush 30 minutes prior to installing the glass, and all the reveal molding clips were installed to the Body Shop-installed weld studs.

The glass was placed on a powered rotating fixture, inside edge up, retained by suction cups.

The glass periphery was cleaned using a solvent, dried, and a different silane primer was applied.

A fabric-reinforced self-adhesive foam rubber "dam" was extruded and applied to the glass just inboard of where the Thiokol adhesive would later be applied; the purpose of the "dam" was to contain any Thiokol "squeeze-out" so it wouldn't show from the inside past the edges of the interior garnish moldings after the glass was installed to the body.

After dam application, pumpable Thiokol adhesive (with a pyramid-shaped cross-section created by the dispensing tip) was applied adjacent to the dam, all the way around the glass.

Lower glass supports were fixture-located and screwed to the cowl, and rubber spacer blocks were glued to the opening flange. The spacer blocks set the height of the glass relative to the body to ensure a good fit of the reveal moldings.

The prepared windshield was removed from the rotating fixture, installed in the body opening, and pressed down against the rubber spacer blocks; wooden tonque depressors were used to "paddle" the Thiokol around the edges at a 45* angle from the top edge of the glass to the bottom edge of the body opening to ensure a continuous seal all the way around the glass.

Reveal moldings were installed.

That was the plant production process, and explains what is sometimes described as a "rope" being found when an original windshield is removed - the "rope" is the fabric-reinforced rubber "dam" that was applied prior to applying the Thiokol adhesive.

If you'll look in Section 4 ("Fixed Glass") in the Fisher Body Service Manual, you'll see exactly the same process for windshield replacement, except the "dam" wasn't included with the Service kit - masking tape was used instead to control "squeeze-out".

The Thiokol installation passed the Federal MVSS windshield retention tests, and contributed substantially to the body's torsional stiffness; it also helped the structure pass the roof crush test. It's illegal to replace a windshield with butyl tape, although some glass shops do it as a less-expensive short-cut method instead of doing the job right."

[pippintook]

I had a mobile glass come and install front and rear glass on my 78 Trans Am. The install cost was $70 for front and $70 for rear. I reused the old rear glass and he sold me new front glass for $150 - this was about 5 years ago. The installer used
SikaTack Drive Adhesive and a Dewalt 18-Volt Adhesive and Caulk Gun. I posted some pics in this thread
http://forums.maxperformanceinc.com/...ght=windshield

[MUSLCAH]

Thanks for that info Brad900

[72projectbird]

Originally Posted by MUSLCAH

These cars had butyl tape from the factory......and that’s what I used in my front and back glass 67 gto. The butyl tape gives you the correct height ,for the the glass....so the moldings fit correct.

I made the mistake of using urethane for the windshield on my 71. The glass sits too low in the opening, making the trim fit weird.

Ever since, I've been using the correct thickness butyl and everything lines up perfectly.

[jimib]

Originally Posted by 72projectbird

I made the mistake of using urethane for the windshield on my 71. The glass sits too low in the opening, making the trim fit weird.

Ever since, I've been using the correct thickness butyl and everything lines up perfectly.

I've heard and read that using urethane can make this project a challenge regarding thickness. I'll certainly need shims at this bottom of the windshield.

[78w72]

Originally Posted by 72projectbird

I made the mistake of using urethane for the windshield on my 71. The glass sits too low in the opening, making the trim fit weird.

Ever since, I've been using the correct thickness butyl and everything lines up perfectly.

the install height of the glass depends on how much & the way you put the urethane on, sounds like you didnt use the proper amount. the pro that did mine specifically stated the urethane needs to be at a certain height/amount to get the correct height, thats the ~1" tall thin wall of urethane i mentioned & how he cut the tip. my trim installs & sits right, just like it did before it was replaced.

[brad900]

Originally Posted by 72projectbird

I made the mistake of using urethane for the windshield on my 71. The glass sits too low in the opening, making the trim fit weird.

Ever since, I've been using the correct thickness butyl and everything lines up perfectly.

You needed to use spacers & have the right size tip. This is the reason to pay a pro

[Greg Reid]

I always put the sealant on the channel rather than the glass. Can't see a reason not to. If it's on the channel, you KNOW it's in the right place.
On the butyl tape question, I use it on my older cars but i agree with brad900 and I can't remember where, but I was surprised to read somewhere, sometime ago that it was not actually 'butyl' tape from the factory but some other product that I was unfamiliar with. I still use it though.
Interestingly, my 1980 280zx FSM instructs you to put the quarter windows in using butyl tape...by name... So, that's what I did.

Wherever I read what I just mentioned and as I recall it was an online magazine article, also said that urethane was a gov't safety requirement in the early '70s so that the windshield wouldn't go flying out of the car in a crash, not for it's improved water sealing. Don't get me wrong, it's great and once cured, it takes an act of congress, or at least a hot knife, to get it out. For me, I don't put my cars together with surviving a crash much in mind so I use the butyl and never have had a problem. One more observation, on our mid/late '60s cars, the trim has more to do with keeping the glass secure than the sealant. I knew a guy with a '68 hardtop that lost his back glass while flying down the interstate with all the windows down and no trim on the back. He said he stomped it to the floor and 'POOF!'
That wouldn't happen, I don't think, with fully cured urethane.

[72projectbird]

Originally Posted by brad900

You needed to use spacers & have the right size tip. This is the reason to pay a pro

A pro did install it, through my insurance no less.

I usually do all my glass myself using butyl, but figured I'd use my insurance to replace my cracked windshield.

Hell I've installed 3 windshields/back windows this summer alone, and all 3 have come out perfect using butyl. It's pretty nice buying a few rolls of it and doing it yourself. A hell of a lot cheaper too.

[crustysarge]

I used 3/8 on the front with non original glass and 5/16 on the back with original rear window, worked just right for height on trim.

[mrennie]

Originally Posted by Greg Reid

I always put the sealant on the channel rather than the glass. Can't see a reason not to. If it's on the channel, you KNOW it's in the right place.

Sorry if I am being dense here, this will probably be more apparent when I actually get to installing the glass...but I don't understand how butyl applied around the edge of the glass could be anywhere but in the correct location?


What am I missing (aside from the fact that this is not the "normal" way it is done)?

[Greg Reid]

You're right and I'm sure you won't have any problem doing it that way.

[MUSLCAH]

Originally Posted by mrennie

Sorry if I am being dense here, this will probably be more apparent when I actually get to installing the glass...but I don't understand how butyl applied around the edge of the glass could be anywhere but in the correct location?


What am I missing (aside from the fact that this is not the "normal" way it is done)?

Yah fingahs might stick to the butyl tape ,when you handle it,for the install. And yah might eff up the placement of the butyl.....but what do I know..