Here is a link to a good discussion thread with people weighing in on the merits of sealing versus not sealing.

I've added my own conclusions with my own point added on pages one and particularly at the top of page two.

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


NOTE
I'd like to leave the glue or no glue discussion for that other thread. It already has some good back and forth/pros and cons discussions building there.

I'd like to keep this one for ideas and evidence.
If you have pictures to add, feel free to contribute those here.

I hope between these two threads we can spare more cars form the carnage...

OMG!!! these cars are pieces of ****, why do we buy them????

Update:

In the thread above (glue or not) http://forums.pelicanparts.com/porsche-911-technical-forum/810979-glue-not-glue.html
we have been discussing if the seals should be installed dry or not.

After all my experimenting in a combination of 80 to -40 degree weather, my own conclusion is that dry is a risk unless your car is guaranteed to stay indoors during wet weather. Remember, once water gets inside the seal it will take an awful long time to dry out since there is no airflow between the seal.

People don't like the idea of glue though.

Per the advice of Timmy2, this is what I am now using:
3m glazing compound

For those of you who are not ready to pull out your glass but are concerned about adding protection, mask the area either side of the seal, squeeze some in under the seal, and clean up the excess using a rag dampened with mineral spirits. It cleans right up

OR, if you are installing the seals, add a bit inside the track during install.
I think the stuff is the perfect solution, and for those ill fitting corners, it even comes in strips that can be added to the body before installing the glass.

If you ever have to redo the glass for some reason, then cleanup is not so bad either.

The Parcel shelf in our 72 was a basket case, as was the bottom of each seat well in the rear, luckily we had a friend with a complete parcel shelf and rear seet clip which we used for replacements. A lot of work in a very confined space to cut prepare and weld in the new pieces, but totally worth it of course. Thankfully no rust in the front footwells or around the front windscreen. Rear problems were all based on the rear shield seal. If only the PO had replaced it. There was no indication on any part of the car that you could actually see, that the rust was under the carpet or seat pads.

But during an engine swap, a screwdriver through the parcel shelf from the engine compartment gave it away!

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


http://forums.pelicanparts.com/uploa...1409320566.jpg



http://forums.pelicanparts.com/uploa...1409322032.jpg

Wow what a mess. I think the car would always have had a very damp, musty smell to it if there was that much moisture creating all that rust?

What is surprising is how much moisture the under padding can hold without the carpet ever feeling damp!

Glaze those seals

Here is how-to

Window Glass Install - Modified Mustangs & Fords Magazine

One more thing I've added to the "I Must Check This Out" list!
I know it's a little old now but Thanks for your post wayner

Cheers
JB

Thanks for keeping this thread visible

NOTE to anyone reading:

While I agree that a fresh stock seal installed correctly an be made not to leak, why risk it? Why the hesitation to glaze that new seal as added prevention for when it shrinks or heat cycles?

Glaze those seals. It cleans up easily with mineral spirits even years later

My favourite quote from page one of this thread.

Check your seals everyone!

On another thread, here is the debate:http://forums.pelicanparts.com/porsche-911-technical-forum/810979-glue-not-glue.html

and here is my advice
If done properly, you shouldn't have to use any sealant, but I like this stuff just in case

Lets keep this thread for evidence of why to check or replace seals, and use this other thread to debate if they should also include sealant or not here : is the debate:http://forums.pelicanparts.com/porsche-911-technical-forum/810979-glue-not-glue.html

Well I live in Florida......where all car get rained on...HARD! And you are never more than maybe 50 miles from the ocean. My 89 is pretty clean (I think), and my new '75 needs a little TLC. I will be going through that one first.....and will be giving both (AND my 996TT) and god once over.

Here is another one.

This time a Carrera 3.2 (galvanized) car.

check those seals!

(fortunately this one was saved and given a second life by its owner...)
http://forums.pelicanparts.com/porsche-911-technical-forum/907880-another-retro-backdate-thread.html
http://forums.pelicanparts.com/uploa...1459306150.jpg

I've had nightmares about this thread for two years. I'm finally pulling my glass to investigate (full thread coming soon, I'm sure), but here's what I found in the front window channel, passenger side.

http://forums.pelicanparts.com/uploa...1518888956.jpg

http://forums.pelicanparts.com/uploa...1518888956.jpg

Just the beginnings of surface rust. Now this car is galvanized, has always been garaged, and previous owners were in Kentucky and Oregon. If rust is happening under those circumstances, it is likely happening in a lot of circumstances.

Seal gap was 2-3 mm on the top and bottom center.

Now, trim refresh, reinstallation, and then on to the Targa window.

Thanks, Wayner for the heads-up!

When I got some stone chips in my windshield this summer Hagerty paid to have it replaced.

My shop recommended factory seals, Hagerty said no problem, they even said I could replace the plastic trim even though my shop was able to replace it without any cracking.

And, it was nice and dry behind the seal.
The diff in $ between an OEM and factory is well worth it compared to the cost of repairing rust damage.

BTW Hagerty was great to deal with.

I have had leaks in my new factory oem seals

Seasonal temp swings between +30 to -30 might contribute

A small dab of the 3m product listed above has kept the 2nd installation dry

In fact if you do have an older car and suspect leaking, a dab under the lip of the already installed seal does wonders

The stuff is almost the consistency of toothpaste, never hardens and wipes off easily with mineral spirits
I don’t see a downside to this safety measure. It’s not a glue or urathane

I have two tubes of the 3M glazing compound ready to go when the time is right. You apply after installation? Also, how did you clean the window channel? Someone had a leak before and there's goop in there.

Scroll up to post #50 for an installation video using the stuff

Error on the side of very little rather than too much. Think of it as creating a very thin gasket rather than filling it with goop

A very very light smeer ( almost a lubricant dab, in fact it does lubricator the seal for installation)

The body to seal Chanel, but also the glass to seal Chanel

After installation it allows the seal and glass to react better to thermal expansion/contraction by lubricating but also self healing the waterproof barrier created by the rubber seal

Wipes up easily with mineral spirits even years later

Many people who believe their dry installation remains dry, actually develop what I call micro-leaks and don’t realize it

To clean up someone else’s mess from using some different material, if it’s hardebrd scrape it. If it’s goopy try mineral spirits although if it is some other material then something like goo gone may work better

Just in from taking the Targa window out. Lots of stuff that seemed like gum from under the desks (yes, I teach). I thought it was just old rubber seal, but it's lotsa what looks like plumber's putty. Is that normal?

Why windshield trim should be a regular maintenance item.
 

No matter how many OEM windshield rubber seals I get installed, the rubber “drops” below the roofline curvature in places over a short period of time. Not good and very much an annoyance that I can’t seem to ever rectify.