Gary C2 UK

Regarding UK replacements.........

I need to have my glass refitted next week and I was discussing this with a friend who used to work for Porsche GB bodyshops and was their bodyshop inspector(procedures & standards etc). When I asked whether I should the screen should be bonded back or put in dry his reply was....

"no you should never put it in dry but at least use vaseline around all the bodywork to allow ease of insertion of the seal." " You can bond them back in if you are worried about future corrosion but the factory(as in UK bodyshops) never did."

Unfortunately he is to far away to get the work done by him so I asked my local independant self employed window man ( whom I've used before). When I discussed it with him he said that normally he would just put the screens in dry. However, when I mentioned my concerns about a dry fit leaving the possibility of trapped water he said that he was quite willing to use sealant if I wanted. Basically he said that "I was the customer and as I was paying then if that's what I wanted that's what he would do"

Ok, if a screen is damaged then you may have a bit more trouble cutting out the seal but I would rather this to finding rust in the future where you have to pay for the screen removal AND costly body/paint repairs.

If Autoglass and the like, who are contracted to the insurance companies are not sealing in the screens then I would let the insurance company know that they are not following the correct "Porsche" procedure and are therefore not going to carry the repair out to a satisfactory standard. In this situation I would simply find a screen fitter who is willing to fit the screen as you wish and then bill the insurance company directly. With this route the insurance would have to pay you is they are not willing to enforce the correct procedures with their contractors on your parcticular model.

Gary

seaeagle

Well, here are the photos of mine. The last owner lived 3km from the beach, but it was garaged. I live 15km from the beach, but its humid city for 3-4 motnhs of the year. There was no evidence of rust on inspection but a year later a little showed up.The photos show the impact. THe screen goes back in in 3 days so i better have a little chat with the man (Porsche specialist body repairer).This is the front screen area of an Oct 90 964. Wasn't too bad and the car is otherwise clean they said which at least is consitent from what I can see. But time will tell. This thread has been very timely and a great help.

SimonExtreme

I am slightly puzzled by the discussions. Having read the workshop manual, I think the most important part in preventing rust around the screen opening is not the use of sealant but the clear instruction to paint anuy exposed bit of metal. If the metal is properly treated/painted, I am puzzled to understand how corrosion can begin, sealant or not,

In cutting out the old screen and cleaning off all the sealant etc, the chances are that the protective paint will be dameged and if that isn't made good, rust will follow, sealant or not! I wonder whether Autoglass do anything about that!

warmfuzzies

If the Autoglass technicians are anything to go by my recent Audi experience then yes they do treat the area. I had my Audi replaced and as I normally do, stand around asking apparently inane questions in a nieve fashion, it fools most people into thinking I haven't a clue and am therefore not dangerous to them.
He was pretty good in getting the screen out, and tidying up the area, but I have rust at the bottom of my Audi screen and its completely original, and the bodywork is galvanised, so I cannot hold with the theory that it's repairs that do the damage as mine was original before this repair....
I therefore have no idea about how it comes about........

Kevin.

springer3

Water in contact with painted steel will eventually cause the steel to corrode. Even the best coating systems are porous to oxygen and water at the molecular level. Part of the strategy for corrosion prevention is to design all parts of the car to drain water and get dry again as rapidly as possible. There are drains in the doors, trunk, headlight buckets, structural box sectins and every other part of the body that could trap water. There are no water drains below the windshiekd, and therefore it must be carefully sealed. Let the rubber seal trap water, and eventually there will be rust.

Adrian made the comment that the factory instructions are made for good reasons. He is correct.

ttAmerica RoadsterAWD

Brought this back from the dead to document my experience......

I'm the 3rd owner. Just removed my windshield (broke it and replacing with "Sheilds" polycarbonate). The metal mounting lip all around has no rust and has the same black, elastomeric/pliable material as "seaeagle" has on his 4-5 posts above. Looks like it was smeared on lightly and can be rubbed off with acetone, but not very easily.

BTW: Stock windshield, with rubber seal, rearview mirror weighed in at 22 lbs. on a bathroom scale.

Jaime

stevepaa

I plan to replace my rear window. I thought I read about using a cutter to cut the rubber seal and lift out the old window but everyone here seems to smash theirs. Anyone not smash theirs to remove it?

Steve Watkins

After any proper repairs, if needed, a neat replacement is to use a 993 glass or poly shield, they are slightly bigger than the 964 glass, however the windshield frames are identical. As it is glued in there is a much cleaner look with the overlapping trim. If you are tracking or racing a replacement windshield is regular maintenance and the 993 glass is usually cheaper.

frankvan

Resurrecting an old thread.

I'm curious about Steve's comments about using a 993 windscreen. Anyone done this?

stevepaa

I just replaced my rear windshield and there was sealant from the factory and I reinstalled the new one using factory sealant. The sealant is to go both in the window groove and on the body per factory manual.

Scamper

I have just had Autoglass out to replace my windscreen. They removed it a couple of weeks ago so that I could sort out the rust in the usual places, anyway he came back Monday and fitted a new screen with my old rubber which was still perfect (kept it in the airing cupboard) and he used sealant between the glass and the rubber & between the rubber and the metalwork.

Did a good job (questioned him originally and he has done Porsches before) and take about 45 - 60 minutes just to fit the new one.

Very pleased with the result.

964russ

I fitted a new screen in my car about 3 months ago, i fitted a new rubber and didnt use any sealent and it dosnt leak. Took me 45 mins and i took my time and rust proofed a couple of scaby bits.
You dont bond a glass in a 964, all the windows are held in by a rubber. They only reason for bonding glass into a car is for safety.

DarrylH

The shop manual seems quite categorical:

(step 15) "...apply the sealant all round the window channel of the rubber seal..."
(step 19) "...apply the adhesive sealant to the body all round the area of the window cutout..."

"Adhesive sealant" is part number 999.915.400.40 for both of the above.

stevepaa

scamper, I am curious how they removed the old windshield without cutting the rubber.

I cut the rubber awy to lift off my old glass intact.

loot87

Because that's how you become more intelligent as a species... by asking why.
There IS always a reason, but it's not always a good one.