Windscreen install

[Sparkrite]

Having finally managed to remove my bonded screen on my tc, I would like to ask opinions on the re install of my new screen.
1, As the new screen did not have a black border which funtions to stop UV rays deteriorating the adhesive. Are the specific glass primers really up to the job, or should I key the glass and use an etching paint instead.
2, As I am thinking of bonding the screen in first, then slicing off the L section under the original trim and then bonding the remaining trim on. Will the trim stay or does it need the L section.
3, On the sides and upper edge of the body screen opening there is a u section trim. What is the trim used where the screen meets the forward edge of the dash top, mine had a plastic rod which bent to the same curve but I do not know if its original.

[Fotog]

There's lots of information circulating, including on this site, but I was just reading last night and thought this information was useful, but of course not the final word: http://www.lotus-europa.com/manuals/misc/Banks_Crash_Pad_Installation.htm
Scroll down to point no. 10.

[Sparkrite]

Thanks for the link Fotog. Its always good to learn more. I hope to have this done soon and I will finally be able to get it on the road for a shakedown.

[SwiftDB4]

There's lots of information circulating, including on this site, but I was just reading last night and thought this information was useful, but of course not the final word: http://www.lotus-europa.com/manuals/misc/Banks_Crash_Pad_Installation.htm
Scroll down to point no. 10.

Very confused that that link recommends butyl adhesive to bond screen to body, then urethane just to fasten the trim?
Isn't just urethane recommended now due to superior strength ?

[gideon]

Isn't just urethane recommended now due to superior strength ?

Yes, that's my understanding too.

[kram350kram]

When I bought the windshield for my Europa and was picking it up at Pilkington, a local installer just so happened to be  there. So I asked him about using urethane and he said use butyl on a fiberglass car. His take was that urethane on the Europa, having such a flexible roof and body that stress forces could transfer to the windshield and crack it. Butyl  allows some independent movement. Using urethane to stick the trim to the windshield should work well as its pretty tenacious stuff. I plan to use butyl to set the windshield and then urethane to adhere the custom wood/metal trim I made to glue the trim to the glass. Sounds like you are going to do what I will be doing only using the stock trim. 

[BDA]

I think I'd vote for butyl also. I didn't feel competent to install my windshield so I got a "pro" to install it. He groused about it the whole time in spite of the fact that it didn't look that difficult to me. He use something from a caulk gun, probably urethane. I am not ecstatic with the job he did but his was the only company I could find in the area that would do it. I haven't had any problems with cracking but butyl tape seems like such an easier way to do it. If I need another windshield, I plan on doing it myself with butyl.

[gideon]

Hmmm,  I'm not sure that voting is the best way to resolve technical questions but here's another vote for urethane from the folks at Steele Rubber

https://blog.steelerubber.com/where-has-all-the-butyl-tape-gone/

I was able to remove the windscreen from my Europa by pulling the trim off and then simply pushing the screen directly out from the inside.  And I didn't have to push that hard.  Ok, the butyl was old, but it does make me wary of it.

[gideon]

Also, some silicone sealant or similar had been applied to the bottom edge of the windscreen, presumably in an attempt to seal a leak.  The PO hadn't driven the car in many years, so the butyl probably failed long before I got it.  I don't know exactly how long the car was put by, but I did get one registration card with the car from 1981/82. 

[kram350kram]

Not to start a war on windshield adhesives, but ... steel cars with rigid steel bodies are one thing, the flexible Europa body with a roof line that sags when the windshield is removed is another. I would think the new Corvette uses urethane with a windshield that is designed as a stressed member and has a vastly superior fiberglass body to that of a 1970 Lotus.  Automakers are always looking for the least costly way to product their products, so in today's world; no labor intensive rubber gaskets, sealants or butyl. The current squirt the urethane and place the windshield is faster and superior than the past gasket and sealer or ribbon butyl. Just not sure the modern urethane applies to the Europa's situation? With the cost and difficulty of obtaining windshields there better be a big upside to using a rigid adhesive. 

[gideon]

Urethane windscreen adhesive isn’t rigid.  3M list the Shore A hardness of their product as 55-60, which puts it between pencil eraser and tire rubber.

[Sparkrite]

I spoke to a recommended fitter by Pilkington and he said use any polyurethane adhesive. I spoke to sika ashesives technical and they said use modern windscreen urethane but all their advice seemed to need to cover their liability so they only recommend what has been tested. If my old sealant (like sticky black bubble gum) was in fact butyl then I believe it does a good job of bonding,unless your out in hot weather when it would surely soften.
Im still undecided but my thoughts are if I use a non windscreen polyurethane adhesive , which is more soft, then this is one step up from butyl.
https://www.toolstation.com/search?q=pu%20adhesive

[Pfreen]

I followed the instructions somewhat that Fotog listed.  I had a professional install the windshield at the house.  He first primed the edges of the windshield and then applied black urethane sealant with an electric caulking gun, which put out a nice even bead on the windshield.
Then, set the windshield in place centering it with rubber spacers.  Push it down a bit until there are no gaps.
I then bought some 3m window-weld urethane at Advanced Auto and glued the chrome and corners in place using tape to hold it in place until the urethane  set.  Urethane cleans up easily with mineral spirits until it sets.  When it sets, it is amazingly strong.

I used the original corners and plastic chrome trim from Sportwing (https://www.sportwing.com/Exterior-Accessories/Extruded-Moldings-Trim/AB10014-S-All-Brite-Molding?limit=100) for the chrome surround.  Someone else online used this for their Europa.  5 years later and it still looks good.

[Fotog]

Having had experience using urethane sealants on boats, I can say that they are very adhesive, resilient, and waterproof. I think they would therefore be quite appropriate for windscreen installation and it doesn't surprise me that the pros are tending to use urethanes more frequently in recent times.  There will be plenty of time to work, but you want to be absolutely certain that it's properly positioned and that you're not going to want to take it out anytime soon.
They can be messy to work with as they'll try to get on everything, but the cure time is long enough and you can clean up with mineral spirits.

[Kendo]

Regarding Sparkrite’s first question, is it worth creating a frit edge to protect the urethane sealant from sun damage? And if so, what would be a good material for that?