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Pupsvette76 11-08-2018 01:03 PM

Lexan windshield install
Hey guys I’m getting ready to tackle a lexan windshield install on my 72 nova, never installed one before. Is there anything I should know going into this. I was thinking of using nutsert in the windshield frame and machine screws to bolt it down. How far spaces apart should the screws be?

39 Sedan 11-08-2018 03:08 PM

Can not give you any information on that part however make sure you have the proper Lexan, i think there are different grades and some will shatterrrrrrrrrrrr easily.

chasracer 11-08-2018 05:11 PM

One issue you will have is the depth difference and assuming you are not using the stock window trim. If you 're putting in say 1/8" stuff and the windshield frame is 1/4 deep, you need a spacer. You can take strips of extra lexan and make spacers. Second item is drilling the holes for mounting. it depends on the curvature but spacing is between 2 and 3 inches. Best way I found was to take masking tape and marking it with a sharpie, then applying the masking tape to the lexan. Oh and keep the plastic protection on it until you are finished. Also if you want a black edge around the window, I found that Krylon was good and easy to do. On the backside, I marked off how wide I wanted the edge and then lightly went over it with a razor blade. Remove the protective sheet from that area being careful to not lift the protection from the rest of the window. New razor blades are a must! Anyway, lightly scuff it with a 3m pad and then shoot it with the Krylon. Two thin coats are about all you need.

cerial 11-08-2018 05:50 PM

Yes lexi not plexi. Plexi will break easily.

OK as far as drilling don't. First your creating a area for it to crack. Second it makes removal a pain.

Lay down weatherstripping and layer it up slightly if need be. The lexan will bend slightly but not much. If you want curvature you need to vacuum form it then lay it down on the weatherstripping.

You then place bolts around the outside of the lexan. This allows you to have a nut at the bottom flush with the Bottom of the lexan when just sitting on the weatherstripping, a tab, then bolt on top.

You turn the tab over the lexan then tighten down the upper nut and it pulls the lexan down the 1/8 to 3/16 into the weatherstripping. Unlike glues or bolts this system is adjustable so as the Lexan and weatherstripping relaxes(and leaks) you can adjust the height of the tabs.

The great part about this is that you only need 6 to 8 tabs to secure the thing. If it becomes scratched, gouged, or damaged replacing it can be done easily.

I don't know the reason why you would want to do the windshield it will scratch if wipers are used for any period of time. Not to mention the legal aspect depending on your area. But having it secured with 6 or 8 bolts pulling the old one out and installing the new one could be done quickly.

ericnova72 11-08-2018 06:13 PM

I've done the Lexan windshield on a street/strip car exactly once.... came to the conclusion the weight loss is not worth the aggravation to me, just for approximately 15-17 lbs lost. It scratches of you try to wipe dust off it, seems like it even scratches if you breathe on it. Can't run wipers AT ALL. Rain-X is the best you can do
Tighten a screw too much and it cracks, shows waviness where every screw is, just sucks if you ask me. A short life if it sees much sun too, it glares and streaks something awful

Do all the other windows if you want, but if this is a car that is going to see any street time, my advice is that it is a waste of time and money to do the windshield.

Find some place else to spend the money making 5-8 more HP to make it up instead.
Better yet, spend that Lexan money on a vacuum pump for the engine and make 40+ more HP.

[email protected] 11-08-2018 08:53 PM

Back in the early seventies I did a Nova. tube chassis/glass front end etc. Used tinted Lexan and the glue in method as described above and as previously mentioned the stuff scratched and smeared badly. Tried many cleaners waxes and polishes. None did a respectable job. On some days. The sun coming thru the shield would partially distort images, such as the tree lights. What a mess. Replaced the shield, with glass, after about six weekends.:spank:

poncho62 11-09-2018 04:36 AM

Wasn't aware that a Lexan windshield was legal on a street it?

Pupsvette76 11-09-2018 06:00 AM

This is pretty much a track only car and even if I do happen to put it back on the street it absolutely never sees rain and it’s garage kept at all times. I’ll have to re read the tab method above because I can’t picture what you’re talking about in my head.

'48 Austin 11-09-2018 06:58 AM

Plexiglass is Acrylic and shatters on impact. Lexan is Polycarbonate and doesn't shatter. it is used to make hard hats, safety glasses, motorcycle windshields, etc.

cerial 11-09-2018 08:48 AM

You put down weatherstripping then just lay the lexan down on that. All the Tabs do is hold it in place crushing it down slightly. Go down to far and you will get the waves that Eric talked about.

I did it on a 2door Cherokee years ago to keep glass off the trail when slapping the side against trees.

It does a good job with wind and impacts. It is ok with water depending how tight you have the tabs.
It seals about as good as the 70/80's 2doors where the door glass was just pressed against the weatherstripping.

Check your class rules some may not allow lexan in the windshield. I would rather run no glass and a helmet then play with a lexan windshield on the street. No problem with visablity and less hassle depending on your location.

ogre 11-09-2018 09:06 AM

imo it scratches to easy, if you use lexan buy 2 at a time
flood with water when washing and use a soft brush, never rag and windex or plex
on the plus side you can use polishing compound to remove scratches

potvinguy 11-14-2018 06:48 PM

Try to get the MR10 anti-scratch coating on it. I've had my Lexan for several years, clean it with ordinary window cleaner and it looks new.

122s 11-21-2018 11:11 AM

I've heard Plexus is great to use with Lexan windows.

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