windshield fit

[Lynn Larsen]

Virtually everyone who I have talked to about the subject of windshield installation has said that they hire a auto glass specialist to do the actuall bonding in of the glass. These include kit manufacturers, car fabricators/assemblers, repair shop guys and home builders. It's just that once its down, its down: there are really no second chances. Over and over again, I have spent 4 hours doing the first iteration of a job, but buy the time I do the 4th one or the other side of the car, it only takes 20 minutes. With a windshield it's got to be done right the first time and a specialist is the guy who does it day after day.

Regards,
Lynn

 

[Mike Dozier]

I've installed butyl tape windshields many times...
very simple...no special skill required although a second set of hands is needed for the few seconds it takes to set
the screen in place. By using rubber spacers, it's pretty
simple to make sure the screen is properly centered.
I believe most shops today use butyl tube sealant rather than butyl tape...but pretty much the same process.

Rubber gasketed windshields are more complicated...I think
I'd let a pro do that one if my kit required a gasket.
But both the DRB and RCR Lola are glue in type...no gaskets used.

IMHO the biggest issue in succesful screen installation is the quality of the spider windscreen area. Compared to mass produced steel frames, the accuracy of fiberglass spiders ranges from excellent to 100 % unusable. I can't imagine anyone
thinking a windscreen would "conform" to fit an out of shape
fiberglass windshield area. The gasket, tape, or sealant does provide some tolerance....but not much.

I'd be very wary of any gaps larger than 1/8 " when the
windscreen is laying in place on the spider screen area.
I'd use fiberglass or bondo to build up the surface to get
it as uniform as possible. Of course the gap from the outer
edge of the screen to the spider should be larger to allow
for glass expansion on hot days, and the thickness of the gasket (if used) and cover molding. That can vary quite a
bit depending on the individual pieces involved.

MikeD

 

[Dan W]

Thanks Mike and Howard for your very informative post. Your info helps lay a path for us RF builders to properly prepare the area before the expert can come out to your house and install the glass or by ourselves. I don't think a professional is going to want to build up low areas with filler (bog), grind out tight areas to allow for clearance, primer, seal and paint the areas , then finally install the glass for that 100 bucks. Id rather not have someone out , and then they cant do the job till its prepared, nor expect them to try and fix some shortfall in the area with a half baked solution. /ubbthreads/images/graemlins/crazy.gifI have installed rear glass in a production car (63 vette)and that went well with a "H" rubber gasket. But like you said the fit was already there , unlike our cars.

 

[Howard Jones]

What I'm talking about is you would make the "seat" area spot on by grinding or adding fiberglass. By spot on I mean when the windshield is laying in the hole there is nearly no fit problem. I would not ask the glass to bend more than 3/32's and with a nice 1/4"gap all the way around between the windshield and the fiberglass body. When you have completed the prep. Then have the glass man out so that all he really needs to do is glue it in. I did not use any rubber on mine I just glued it in with the proper stuff the windshield guy had.

 

[Howard Jones]

Oh and if only one corner of the spider id 1/2" low then you might be able to "fix" it by bolting the spider onto the chassis and then putting a straight piece of 2X4 between the chassis and the low corner of the spider theirby jacking the corner up and causing the fiber glass to take a new set in the correct posistion. Put the whole project out into the HOT sun and get it all good and warm then heat the area to be streached with a blow drier. Be careful not to get it too hot and F.I.U.

When you have the corner jacked up into place then trial fit the w/s. If all is good then bring in out of the sun and let cool down with jack in place. After it is cool remove jack and trial fit again. You will have gained a little but more than likely will need to do again and again until all fits ok. You will find that you need to over "jack" the spot so that when it relaxes it is in place. This process will take some time but will save on adding fiberglass. I would try this before I went to adding a 1/2" of filler. Fiberglass or whatever. Oh and when you do use filler have a look at Vete pannel adhesive. Its a green bondo type stuff but is about 4 times harder than plain bondo. Its made for fixing corvettes. Very strong stuff and is much better that plain bondo.

Do not use bondo on edges of fit lines that need to be built up. It will chip off. Lay on strips of fiberglass mesh about 3/4" wide. Only one layer the first time so that you get a sort of table to work on then put on 2 or 3 layers at a time and then let setup. Then again until you have a good fit and wait until you have a complete build up before you trim to shape.

 

[DMatt]

Howard,

Thanks for the feedback. I wondered how the glass would look without the rubber installed the way it seems you have done yours. I looked in the builders forum to see if you has a thread of your car but I did not find one. Could you post a picture of your windshield set up?

 

[Lynn Larsen]

Just a note on preping the windscreen surround. I found a pnuematic inline sander to be a very helpful tool in working both surfaces. I am sure an electric would work as well or better, but air was what I had.

Locked in my vise, it was also very useful in sizing and beveling the edges of the lexan side and rear windows as well. This is a must have tool in my opinion.

Regards,
Lynn

 

[Howard Jones]

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[Howard Jones]

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[Howard Jones]

Lynn is right you can buy a airboard for as little as $69. They are a must have for doing you own body work.

 

[Phil]

Howard
Photo #6 looks to be the best fit....but possibly a high maintenance setup!
Phil

 

[Howard Jones]

This is of course a depiction of the relative size of the pilot of my GT40.

 

[Phil]

Howard
My mistake...I should have known it was for research/scientific purposes only. But the view is nice.
Cheers
Phil

 

[Jim Dewar]

I found the answer to correct windshield fit! I called my local glass guy who stopped by and checked my clearance problem, marked the glass for correct fit in the spider opening and carried it to his shop to grind the excess glass away. The clearance is now perfect all around the windshield so my weatherstrip installed, seats perfectly in the spider opening.

 

[DMatt]

Jim,

I was just talking with Dan W about this very issue while you were posting! I'm sure he will be glad to see this.

Hope all is well on the home front.

 

[Ron Earp]

So calling the glass man wasn't a bad deal huh?