windsheild install ? caulk? or not to caulk?

tony77targa · 05:21 PM

Any glass guys out there to tell me the professional way to install a new windshield rubber?
Thanks
Tony

Schrup · Schrup's Garage

I'm no professional, but a friend helped me install mine a couple weeks ago. After we got the windshield in, I squirted some black windshield sealant under the rubber seal into the gaps, mainly in the corners & by the posts. Got the sealant from a autobody supply store. Black glazing compond was recommended, but I couldn't find any.

masraum · 04-07-2004, 01:23 PM

I don't think you are supposed to have to put any sort of sealant in with our windshields, but I know several people on the board have.

Our windshields are supposed to be held in by the gasket and trim.

slater · 04-07-2004, 01:39 PM

You dont need to use any kind of sealant if the rubber is in good shape. Put the rubber on the glass first and then take a long piece of string ( i prefer wire) and tuck it in the seam on the rubber. It can be a real PITA to get the string in but it makes the job so much simpler. After you get the string in, set the glass in place, have somebody put a little pressure in the outside of the window (not too much pressure on old glass - any small chip on the edge could crack the whole window) and then slowly pull the string out from the inside of the car. This pulls the rubber into place and sets the seal. It actually goes pretty fast. Hope that helps

Decolliber · 04-07-2004, 02:12 PM

I had a new windshield put in recently at local auto glass shop. I provided the installer with an OEM rubber gasket ($44 from Pelican, cheaper than aftermarket gasket they would have sold me). He told me that that no extra sealant was necessary because the OEM gasket has a sealing compound in it.
I watched him do the whole thing. Took about two hours. The hardest part was getting the old metal trim piece into the new gasket. Seating the windshield in the frame was very quick. I had not realised how heavily pitted my old windshield was until I drove with the new one. I am glad I did not try to do it myself, though next time I might ...
Total cost = $360, and the windshield is a Sigla.

NoLift911 · 04-07-2004, 02:44 PM

I have installed 5 front windshields and 1 rear one. If you use Porsche OEM gaskets and Porsche OEM glass you need no sealants or caulk or goop of anykind. No leaks on any of the installs.

Makes life tough if you ever have to replace the glass as well. Say 4 times?

tony77targa · 04-08-2004, 05:22 PM

ok The string worked great and the windshield with new rubber is installed.. how the heck do you get the freakin alum trim installed in the groove? Thanks much to all that gave input up to this point and thanks for any input in advance

radcon · radcon's Garage

I wish you would've asked this in advance, because you have to put the seal on the window, then put the trim in the seal, then install the window. Once the windshield is installed, there's no way you're getting that trim into the groove. Sorry, you'll have to remove it and start over.

jerkan · jerkan's Garage

You really have to put the trim in before the windshield is installed. Now there is no way to install it, unfortunately. No caulking is needed if you use OEM seal

dean · 04-08-2004, 05:43 PM

The factory manual says to put sealant in

UTKarmann_Ghia · 04-08-2004, 06:26 PM

The pros who did mine added sealant around the edges, works for me.

geof33 · 04-08-2004, 06:38 PM

Caulk??? Can you say that word in a public forum???

tony77targa · 04-09-2004, 01:53 AM

Yes tis the age old question....
to caulk or not to caulk......
Ok windshield comming back out add metal trim glass back in with caulk.
thanks everyone!!!

Glasgow 911SC · Glasgow 911SC's Garage

Mine leaked after reinstallation (with new seal). I'd use sealer.

tony77targa · 04-09-2004, 10:38 AM

So ......
I went to the Home Depot to get some silicone caulk and I was juggling a few items and trying to get my wallet out and having a hard time sos I asked the checkout lady if she could hold my caulk

Decolliber · 04-09-2004, 11:49 AM

Are you sure you want to use Home Depot caulk? Its not the same as rubber sealant. If you are concerned about leaks, just use some ice wax. I recall some previous posts on this from people who say adding sealer will make it squeak. My installer was quite adamant that if you use OEM rubber there is no need for extra sealant. What does Bentley say on this?

Mike Lindsey · 04-09-2004, 02:02 PM

I have installed 911 windows for nearly 20 years, I have always used a sealer between the seal and the body. the factory used a urethane sealer there, that is why you have to cut the glass out on an original seal.

It is not necessary to use that permanent of a sealer, 3M makes a product called bedding glaze. A thin layer spread around the frame of the glass is all that is necessary. It is sold in a calking tube but is not expensice, less than $10 if I remember right.

This material remains plyable over the years and does an excellent job. There is another sealer for the glass side of the seal but it is not as necessary as the body side.

The rubber must be installed on the glass first, then the trim installed into it.
Use WD40 to lubricate the seal and window trim to allow it to slid into place more easily, the WD40 also works good to remove the gray mould release agent that remains on the new window seal.

A light film of Vaseline spread onto the seal works well to help the glass going into the car.

You need three people to assure a good install the first time. Two on the outside to guide it in and hold down on the trim in the corners so it doesn't come out of the rubber as it is roped in by the third guy.

Start at the bottom in the center and pulled the rope around one side until you are about half way up the A piller.
Then do the same with the other side.
go the rest of the way around and stop at the mirror, then back to the other side and finish the pull.

Now all you have left is the mess to clean up, but it wont leak.
Be careful, they can break going in. The early cars up to 89 arn't bad. the 964 glass without the window trim are a much bigger headache. I would not recommend trying one of those without experienced help.

good luck.