Re-fitting windscreen. To glue or not?
 

I am about to remove and refit the windscreen in my early (2/'73) 911 (the 20 year sleep). Our hosts book,101 projects doesn't mention glue but the Haynes manual does,so I tend to take notice of our host. Reason for job is a couple of rust spots and a new rubber. Michael.

No glue as I recall.

Unless you are update to the 964 or 993 windscreen and seal.

For a car that's driven daily in all weather you should use a non hardening mastic type sealant. (in my opinion) Most professional windscreen fitters use this by default.

For a car that's stored during Winter and driven on selected days the rest of the year I wouldn't bother.

I read over a bunch of threads on this topic. It seems the general consensus was, if you put the new wind screen in and tap the metal bead that secures it in place so that there are no gaps then don't use glue. I didn't install any sealant on mine when I installed it in my 85. I formed punch out of some thick plastic and tapped on the metal to move the seal into place. Most of the people said that you should use this method to get the seal into the proper position and then check later after the seal had been installed. If a gap opened up, tap the metal over to close the gap. I haven't had any leaks on mine over the last two years.

Here is my conclusion after 3 years of experimenting:

You need something if you want the seal to stay dry, but glue may not be the best thing.

Here is another two threads that I have been feeding on this topic.
My conclusion is on page two of the first thread. My extensive test methods and results are documented in the second thread.
Many people have success with installing dry, but I am not willing to take the long term risk that it will stay dry.

http://forums.pelicanparts.com/porsche-911-technical-forum/810979-glue-not-glue-2.html

http://forums.pelicanparts.com/porsche-911-technical-forum/686953-why-windshield-trim-should-regular-maintenance-item.html

This thread (below) is quite long, discussing at length the gaps that frequently occur in the four corners of the 911 windshield. There is much discussion of various glues and sealants, but the salient part of the thread that most impressed me was the Randy Blaylock input on use of a "wedge" to shape the aluminum trim that goes within the windshield rubber. Cabmando mentioned this in his post above, but the full discussion is within this thread.

http://forums.pelicanparts.com/porsche-911-technical-forum/330161-gap-between-rubber-windshield-seal-body.html

It seems that Porsche mentions using something in the factory manuals, but I don't recall the brand off of the top of my head.

JR

I just removed my windscreen to take the dashboard out, and am so thankful there was no glue. I can't imagine what a pain it would be to first try and remove the windshield without breaking and then have to scrape all that off. If it is nonhardening it might be ok, but it would still be quite messy to put on and a pain to clean off. Mine never leaked without glue. There is plenty of proof that you can have very good seal without glue. If you ever have to remove the windscreen again, you will be thankful.

There is no reason to glue these in place totally not needed, from factory they are put in dry with no sealants. Start with a good oem rubber and new moulds and you won't go wrong, make it easy on the next screen change, no mess and sealers all over the body.

No reason to seal them at all. The primitive factory technique does a fantastic job, and cleaning this up is much easier than cleaning up sealant ;)

(See my threads above and the 3m product if this picture concerns you)

http://forums.pelicanparts.com/uploa...1409320268.jpg

Which will make the car slightly more rigid. But if it gets a stone chip, makes replacement a PITA.

I don't use sealant just thick clear spray silicone to aid in installing the glass.

Unless you leave your 911 out (not under roof) there is no need for the mess of sealant.

When washing I'm careful in these areas and I use compressed air to dry the areas I know can hold moisture.

I also take out my glass every so often to check their channels. This can be done every few years.

Can't do that with sealant and sealant does not guarantee moisture still will not collect.

I agree how you use your car is a consideration. My installer talked me out of any type of adhesive because I am planning a windows out paint in a couple of years, and also because I won't drive it in the rain.

No glue in my 5 year old seal, driven in rain, fog etc. no leaks at all.

Everyone, thanks for all the responses,so no glue is the go.will let you all know how I got on in a couple of weeks when I get home. Michael. http://forums.pelicanparts.com/uploa...1440020187.jpg

[QUOTE=and sealant does not guarantee moisture still will not collect.[/QUOTE]

I'll second that as well.

no glue please

Nationally known glass replacement service house call to replace mine around 1998. Older (late 30's) tech said these cars don't require sealant on the windshield while tweaking the metal seal trim back into shape with glass on the saw horses. 40 minutes out and in.

He had to seal it for warranty purposes, though. Next go-around when I painted the car in the early 2000's, I used no sealant with a new seal.

I read in another thread that the porsche seal is fitted to the windshield in that the corners of the seal are formed for the corners of the windshield. I ordered a new "Genuine Porsche" seal and it is not formed at the corners. It's just a seal with one seam where it's glued together. Did I get the wrong part from our host?
Thanks

Ordered an aftermarket seal and it did not fit well
Replaced it with a Porsche one and the corners to the body still dont fit when
Should I glue the corners?
Thanks

What is your procedure for installing? If you get the inside lip over the metal correctly, there is not a lot of "don't fit" room left for play when you have the metal trim in. You lubing the window up well?