Oddjob

I just pulled out a cracked/busted windshield, and Im going to have the entire car painted before installing a lexan windshield.

I want to remove all of the remaining rubber gasket/frame and adhesive, down to the metal, before having the car painted.

If I do remove all of the gasket and residue, do I need to buy a new rubber frame gasket to install the lexan windshield? PET shows a separate gasket that goes between the glass and the car frame, and then the seal on the outside of the glass. I think some of these gasket frames actually come installed on replacement Sekurit glass, but obviously the lexan does not have anything. Is it needed? Or can the lexan be glued in directly to the car frame?

Also, the factory glass has a black border painted around the edge, approx 1" or so wide. This hides the adhesive when looking at the window from the outside of the car. The lexan does not have this painted edge. Does anyone have a lexan window installed? Can you see the adhesive through the lexan, and does the edging look bad?

Burma Shave

You will not be able to use the oem reveal moulding (outer seal) with a lexan windshield as it fits in a track that is attached to the sekurit glass. For lexan I would use butyl tape for sealing and paint the outsde edge black for appearance. Do you have a cage installed? The original windshield is a structural member when installed properly with urethane adhesive.

shiners780

Hey Jim,

Please post back on how you installed the lexan windshield once it's complete. I will probably switch to lexan when my windshield cracks next time, and would appreciate seeing some examples of installs.

Oddjob

Burma,

Yes I have a 6 pt. cage, with A and B pillar tie-ins. I am not asking about the external lip seal around the windshield (I will use the factory seal, but probably end up gluing it in).

Im more curious about what should go between the glass and the car window frame. Right now with the glass out, there is still about a 1/2" thick/tall seal, that appears to be a rubber gasket that is glued in. Its pretty chewed up and there is some rust showing underneath it. So I want to remove it, clean up the metal, get it repainted, then install the lexan. But I want the lexan to sit at the same height as the glass would, so I think I need to replace this gasket/adhesive. Looking for someone that has removed and installed their own windshield for some insight on this.

Did you remove all seal/gasket/adhesive residue for your repaint (Im assuming your avatar is your car)?

If so, did you put in a factory windshield? And does it require an additional gasket between the windshield and the car, or is that component included with the plastic channel that comes already attached to the window?

ehall

bumpety bump. I'd like to know as well. I'd like to pull my windshield and reseal the black area where the UV has broken it down and made it grey.

420WHP944

Oddjob,
I had my windshield replaced when I painted my car this last october. I did paint the car with the original windshield in place but the outer surround rubber was removed as was the plastic channel that runs around the windshield that holds the said rubber in place. With the rubber and plastic channel removed it gave me enough space to get nice new paint in there. The guy who installed the windshield pushed the old one out and he did scrape away the old bonding rubberised/silicone crap from underneath leaving a nice fresh level bed for the new winshield.
So yes, scrape away all the old bonding material before your new screen is replaced.

Oddjob

Had a pro-installer come out at look at installing the lexan (guy has experience installing lexan/poly carb for the local p-car race shop).

Said that the lexan cannot go straight into the stripped window frame. I need the backing rubber seal that comes on the factory 944 glass. When the factory glass is cut out, the backing stays glued in the window frame, and the lexan is mounted to that. Told me the best option is to buy/install a new factory windshield, race it until it gets broke, then cut it out and install the lexan.

potent951turbo

Has anyone priced the backing seal and that goes in between the frame and windshield along with the outer seal from Porsche?

Oddjob

The outer seal/weather strip is about $25-30, I just bought one.

According to the installer I spoke with, the inner gasket/frame seal is not available as a separate part, it only comes pre-installed on the Sekurit replacement/factory windshields.

Looking at PET, there is a separate inner gasket shown, but its unclear what model years that is for. The installer said that is not the correct part, and do not order it - it wont work (?).

potent951turbo

I ask because I have a wrecked 944 that has a very nice factory original windshield that I would like to remove and use to replace my cracked windshield but if I can't get the seal that goes in between the glass and frame will I be unable to use it?

Mike Buck

Jim,
I put a lexan windshield in my car back in january. I will post up a longer reply when I return from lunch/gym. Don't know how I didn't see this thread when you first posted.

PorscheDoc

I just glue the lexan windows straight to the frame of the car. You will lay a very thick bead of glue. Also, you are probably going to want to use some screws to ensure the window does not let go from the glue, which I have seen happen. I use short thin strips of aluminum, and place it over the edge of the window, then screw it though the window (after predrilling of course), and into the frame. Then it won't go anywhere. You could probably do it without the aluminum strips, but I don't like taking the chance of the lexan cracking around the individual screws.

Mike Buck

Jim,
Over the winter I installed a used lexan windshield in my car. Although I needed a new windshield due to some rock damage, a lexan windshield wasn’t really in the cards for me. Cheapest I saw new was around $450 just for the lexan. I could get an OEM for less than that installed. As it happened, I came across a used one in CT through the PCA classifieds. Only $125 and it was near where I was driving for the holidays anyway. The local glass place would not touch it, but after talking with my cage builder and the seller, I reasoned it would be a feasible idea. Mitch said he could install it and I figured lexan might not be so bad considering I do a lot of events at Summit Point where rocks and stones are abundant. If it cost me less than $450 altogether, I was breaking even at least vs. new.

Picked up the windshield from the seller and it was in pretty decent shape. Few scratches, but it was a race used piece at a good price. Seller included 5 pieces of hardware he had fabricated to hold the perimeter down. I have circled those in the first picture below. Seller had the windshield glued into his rig and along with the hardware in place, it was good up to 160mph with no additional bracing. His car had an LTI V8 swap. My car doesn’t go more than about 135 on the tracks I do, so I should be safe as well. Think the lexan is 3/8” thick, but maybe less, I forget.

Dropped the lexan and hardware off with Mitch and the first pic below is what I came home with. You can see around the edges where the bead of urethane sits. Apparently the lexan was a bit undersized and he had a difficult time getting good even engagement around the whole outside. The gap between the windshield and body was bridged with a universal 3/4”-1” gasket, which is quite a bit wider than the factory rubber. It looked pretty good and with a little polishing, visibility is perfectly fine in other than direct sunlight. The hardware pieces were installed three at the bottom and two at the top. With no black edge around the lexan, the urethane was very visible, but easily covered with black vinyl strips and a windshield banner.

Took the car for the first race back in February at VIR. On the back straight cresting the hill as I go past 120mph the windshield begins to bow in and out a bit. Not drastic, but you can tell it is moving. I quickly learn to ignore it. After a session or two, I notice the drivers side upper corner edge molding is not so flush with the roof anymore. The urethane has released (looks like he got sloppy here laying the bead) and I can actually push the lexan up a bit. A bit upset, I tape the corner down with racers tape and have no further issues for that weekend. See second picture. I even ran a race in the rain witih no wipers using only rainx. Rest of the perimeter of lexan was rock solid glued in place still.

Took the car back to Mitch and he suggested adding two more braces to hold the windshield. One on either side toward the top. See bottom picture circled areas. Curved aluminum pieces held on with two captive nuts into the a-pilar and pushing down on the molding/lexan to hold it firmly. This configuration has been tested at two events now up to about 135mph and it is working fine. With 7 braces and the urethane I am fully confident the thing will stay in place for my uses. Total investment is still less than a new OEM glass. The lesson here is to have bracing on at least all 4 sides and optionally install blow in or blow out straps(think nascar), but they will add to the labor greatly. Mitch wanted to use all new hardware of his own design, but he worked with what I gave him and added to it to come up with a working solution. I clean the lexan with 5star plastic polish (like plexus) and a terry towel. Works great.

If you want better or more detailed pictures, those will have to wait until I am home again in a few weeks.

MarkRobinson

what chemical do you use to strip the old guey windshield seal away with?

I'm placing a Lexan in this weekend but there's so much goo...and Denatured Alcohol barely touches the stuff: recommendations??

Mark

FrenchToast

If anyone here is considering putting Lexan on a street car, or a car that even sometimes is driven on the street, I wouldn't do it, for seeveral reasons:

In some states its illegal.
The dust etc. on roads will pit the Lexan. Even if you can't 'see' any dust on the roads, theres a lot more than on a track.
If you accidentally run the wipers on dry Lexan (easy to hit the stalk) you'll scratch and ruin the Lexan

However, Lexan is easier to install than glass since you can bend it fairly easily.

Take care!