Convertible D windshield installation help.

[Ron Guest]

I have been slowly restoring my D, #86717 for quite a while and have come to a stopping point with the windshield installation. I have read all the posts in the forum on the subject and talked with a few shops about the process but I am not comfortable attempting it myself, at least not without an experienced person on hand to guide me. I am also uncomfortable giving it to a shop that has never done one. It is the original glass and original rechromed frame but the car had the curved strips at the cowl removed. Does anyone know of a shop in Northern California that has experience with this process? Actually I would find a way to get it to any shop in California that can help me. Thanks in advance.

[Martin Benade]

Was the cowl reworked in any way? If so the glass might need grinding to fit which is not that hard for an experienced glass guy but nobody will guarantee not to break it.

[Ron Guest]

There was a ‘small’ amount of filler added for smoothing but most of it was blocked off before the primer went on. I don’t know how much clearance is needed between the glass and the rubber and frame but I can’t imagine the tolerance is so close that we exceeded it. But that’s why I’m asking for help, I don’t really know.

[Edwin Ek]

I am in the same boat, with my Roadster. By all accounts, this is a very, very tricky job. I was given this fellow's name by one of the top shops here in So. Cal.

We spoke in April of 2018. He is based in Anaheim. RJ Auto Glass is his company, (714) 292-5811 is his mobile number.

My notes from that conversation: has been doing this since 1983. Estimates he has done 50 Roadsters. No guarantee if he doesn't supply windshield, and he only supplies American ones. Nice guy, heavy accent. Charges $250 if not installing rubber; $450 if installing rubber. Does work for European Collectibles.

[Martin Benade]

He sounds like exactly the right guy for the job.

[Adam Wright]

This was the sign on my car when it was at the paint shop, I told the guy if he breaks it, we are doomed!!!!

[Drew Ogden]

There is an old Mexican guy in East Oakland who is a real master with this exact issue. He used to do a bunch of work for Jim Barrington. I had my D at several different shops and no one could get it right (I wont mention the shops, but they are reputable and known within the California 356 circle). Anyway, it dragged on for over a year. There were some unique issues with mine, mainly caused by incorrect attempts by the first guy. I reluctantly dropped it off at this guys concrete walled barbed wire compound and had a perfectly installed windshield a week later. Jim Breazeale or Dave Merz can probably put you in touch, I have lost his contact info since. Maybe contact them off line, I imagine you know Dave since you are in Sonoma...

[George Hussey]

maybe as insurance have two windshields available. I have done quite a few roadsters myself, and it is not something I would EVER look forward to doing!! As previously stated, match the curve of the bottom of the windshield to the cowl first to see if you have a uniform line. Because of all of the aftermarket parts, like the seal and trim, and the rechroming, and current manufactured windshields there are many variables making this a tough job

[Roy Smalley]

Every cowl curvature is different after measuring 6 D, Roadsters in shop at one time years ago....ditto speedsters, but speedsters are a lark compared to roadsters.... Some roadsters are a lot different ( I have seen 1/2 inch on an unmolested 61 dieteren with no apparent upset post manufacture. It has been several years and it hasn't popped out yet, but very close). The best plan is to fit with rechromed parts, new seals and whatever aluminum strips you are planning to use, and check the fit of the two seal retainers. My experience if you can restore the original strips that is what I would do. The whole enchilada. The windshield gets a lot of blame. Years ago when there were a bunch of glass manufacturers the main problem was thickness of glass. Now the glass is pretty decent.

Always fit the windshield assembly, the roll up windows and the top frame to check fit and alignment.

Sometimes it takes more than one attempt with the cowl seal, perhaps two different sources. Some work, some don't. Some reproduction aluminum strips work, some don't.

You can keep the assembled unit together with a lot of tape for install later. Carefully.

[Roy Velthof]

restoring my roadster next year and already reading up about best way to remove the windshield , dissasemble , reassemble.
The frame needs rechroming; so will have to be completly dissasembled.
Are there any key points to address when dissasembling, so assembly later goes smoother?

thx

Roy

[Ron Guest]

Thanks to all who replied to my post. I ended up with a very nice, and very informative visit to my house from registry member Denis Moore. We discussed the process at length, including do’s and don’ts and things to watch out for. He has written an article on the subject that is in the archives on this site. He has installed a number of these windshields and the article is very detailed about the process. If you are contemplating installing your windshield yourself I highly recommend reading it first.
My glass is not in yet due to a need to rechrome one of my pieces but I will update the list when it goes in. Thanks again and thank you Denis.

[Ed Pimm]

These factory Porsche dealer bulletins have helped me install many windshields.

porsche ws3.jpeg (496.07 KiB) Viewed 1161 times

porsche ws2.jpeg (237.13 KiB) Viewed 1161 times

[Dan Haden]

Ed's inclusion of the factory bulletins on Conv D windshield installation has prompted me to add in my two cents. I think I may have sent my recount of installing the windshield on my D so it may already be in one of the threads mentioned above. I apologize for any repeat information. But the factory instructions should be amended to add the following warning:

"These factory instructions apply when you are using original 1959 factory OEM channel rubber, base rubber, windshield glass, metal angles and the original position of the metal angles. Also these instructions assume that you are using original factory OEM frame and frame uprights that have not been changed in any way."

Since it is unlikely that the above conditions apply to any car being worked on today, I would warn you to not take the specifics (especially dimensions) at all seriously. Doing so will only make your installation even more miserable than it will otherwise be. Example: the repro base rubber profiles are quite different in how they interact with the metal angles. Example: the dimensions of available windshields are different than originals. Contours of available windshields at the bottom especially are different enough that fitting a repro base rubber and a new windshield can sometimes be almost impossible to make work because the windshield and the base rubber profile leave a gap between base and glass.

Below is a recount of my experience assisting Bruce Baker, who has done quite a few of these operations, on my Conv D back in 2002. Incidentally, Bruce tells the story about a Conv D brought to his shop by its original owner who wanted the dried out rubber on her windshield replaced. The car was completely original and unmolested and the woman handed over bags of original NOS base, channel and post bases she had obtained from the basement of a German Porsche dealer on a recent trip to Europe. Bruce was able to replace the rubber completely and reinstall the windshield in about an hour because all of the rubber was the same shape as what was removed from the car.

New, expanded and improved version, done 11-12-03:

It took us about 3 weeks of 8 hours plus per week to get the windshield on right. I had bought a new Sigla glass, which we used. It fit the frame pretty well, requiring only a little straightening of the curves of the frame near the ends. We put it all together using cardboard shims and tape to hold the glass in the frame in the proper position and then used the factory bulletin recommendations for measurements to locate the metal angle strips on the cowl. (The metal angle strips usually have to be recontoured as well as relocated. Get out your metal shrinker and stretcher and get to work.) Then we tried to fit the base rubber and had to trim and doctor it to get it close to laying down properly. (This involves razoring off strips of the "bulb" that is the part of the base rubber that forms the channel for the bottom of the glass. It is too thick to allow the base rubber to sit down flat on the cowl.) We finally got it seeming right with only the right side near the vent not laying down well. We had moved the middle of the metal angle strips farther back to help things (we had moved the entire strips back more than a quarter inch from the factory position when we did the factory bulletin adjustments). In the almost right position we tried to install the 5 piece aluminum trim and found that putting it in held the rubber base down (except at the bad place near the right vent), but that in installing it we could not keep the rubber from pulling off the bottom of the glass. We took everything off again and reconsidered. We had been planning to not install the frame channel rubber in one piece, but rather to hold the glass in with shims and caulk and to glue the edge of the channel rubber the "lips") on at the end. (This is a normal procedure because if the glass/frame fit is not very, very good the full rubber seal can cause the frame to put stress on the glass, and we all know what happens when there is stress on the glass. Clink.) Because the glass fit so well in the frame Bruce thought we should go ahead and try to use the channel rubber after grinding off the internal ribs. When we did that we could bring the glass down a bit further (because the rubber "lips" stick out beyond the edge of the frame the glass can be moved downward and the "lips" will still grab the glass. If you are gluing the "lips" on after the installation, you can't count on the "lips" to give enough mechanical grab to really hold the glass). Using small pieces of base rubber section and moving them around we found that we should probably move the angle strips forward an eighth to a quarter inch. (Do you notice that we are getting them back to near their original position? The factory bulletin method doesn't seem to work well for repro base rubber.) We did that (drilling out the pop rivets for about the 6th time), installed the base rubber and found that the angle of the glass as it fits the base rubber to be greatly improved. The purchase of the base rubber on the glass was better than before, but still tenuous. We used 3/16th inch aluminum shims at the rear of the post bases to pitch the whole frame more forward to lower the center edge of the glass. Installation of some foam weatherstripping under the base rubber in strategic spots also helped to solve the problem by pushing up the glass groove part of the base rubber. Getting the 5 piece strip installed took some doing, as the contour of each of the components was slightly different. (This entails the 'string in the groove' process for those who haven't been through this. I got so I could regroove the string in less than 10 seconds after 20 or 30 tries. If they were still making these things, I could work on the assembly line.) One piece went in perfectly, but the other two finally went in with some spots where the rubber at the glass was a bit lower than perfect. (Putting the five piece strips in the rubber changes the way the rubber is shaped.) The original aluminum tabs that attach to the wiper tubes were much too short -- new repro ones are longer and have elongated holes. The new ones fit the bill with only a little jiggering. After all was in place the gasketing was siliconed into place, holes and gaps filled and smoothed with silicone and any base rubber lifting adhered down to the cowl.

I estimate that we put the windshield assembly on and off the car 30 or more times. Almost every time it had to be bolted down and the rubber post bases picked into proper position. In hindsight it is probably a miracle that the glass was not damaged in one of these operations. (Bruce and I got so we could install the frame with glass on the car with post base rubbers properly located in less than a minute, fully tightened down. All the rest of the time went into fitting, measuring, fiddling, trial and error, and banging our heads against the wall.)

Lessons learned: rather than doing a "dry" fitting of glass in frame with shims to set base metal angles it is better to get the glass with channel rubber put in place before checking base angle placement. (This assumes that the glass/frame fit is good enough to use this method. If it is not, the 'shim now and later glue in the channel rubber "lips" method' will have to be used.) Then using sections of base rubber the best placement (and curvature) of the metal angles can be determined. Use actual scrap pieces of base rubber to check for metal angle placement as the dimensions in the factory bulletin do not seem to work with the repro rubber. Only then should you drill and pop rivet the angles in place. If we had followed this procedure, we would have reduced the time spent by more than half. If the frame has been on the car before and no new part is added to the equation, it is likely that little or no movement of the angles will be needed. If the base rubber is new or glass is new, it will probably require moving the metal angles. Much of the work required is caused by the new glass having a slightly different contour than the original and a considerably shorter center section, leaving too much space between its lower edge and the cowl.


Added 12-4-03

I spent a lot of time trying to fit the side window rubber seals and the side window glass to give a proper seal. On the driver's side (I think) the window track in the door had to be adjusted all the way outboard plus some (with grinding) to even get close. The rubber seals had to be cantilevered and shimmed out somewhat to make a seal. The other side was better, but it was still near the limit of the channel adjustment.

After I was done I tried to figure out why things were so hard to adjust. Looking at the car from front and rear I noticed that the top frame was lopsided slightly. In other words it was bent so that it was pushed to one side and was not symmetrical. The top had been fitted to the frame so it looks fine, but the frame is not straight. Presumably if the frame is made straight, the windows will be able to be adjusted more easily and nearer the middle of their range rather than at the limits.

If/when the top is replaced, the frame should be straightened and the seals and windows readjusted to a more normal position. I suppose it is possible to straighten the frame before then, but I would worry that the top would not fit properly, which would probably be a bigger problem than the window sealing is now.

[Harlan Halsey]

I am surprised that no one has mentioned difficulty with fitting the aluminum base trim strips. My originals were beat up by the wipers, but I found the Stoddard replacements impossible to form into the compound curve of the side pieces. The aluminum was much harder than the originals. I have since learned how to anneal aluminum Carrera bumper decos, and I intend to try it on the D windshield trim.