Tinting 1973 BMW with Curved Rear Windshield

June 5, 2010

I have a 1973 BMW 3.0CSi. This model has a large curved rear windshield. A photo of the back of the car (not mine) can be seen at http://www.volocars.com/1973-bmw-3.0-cs-coupe--c-1141.htm. My particular car is red with a tan interior. I had the glass tinted, and I'd like to bounce some questions off y'all. Let me tell the story and the questions are at the end.

I recently drove the car 800 miles to a vintage BMW event. The air conditioning usually keeps up with summer heat, but after several hours in 95 degree temperatures, the interior of the car was very hot. When I arrived at the event, I mentioned this to another owner and he asked me if I'd thought about tinting the windows. I said that I didn't want to change the look of the car (which is old, European, and has clear glass), and he said that there were new band-pass ceramic tints that were nearly clear and blocked 99% of the UV and 70% of the heat. He mentioned some German-sounding name but I forgot what it was.

When I got back home, I did some searching online and found many references to the Huper Optik band-pass ceramic tints. I figured this was probably the product that the other fellow had mentioned. I then found a highly reputable, highly well-reviewed shop in my area. I called and he said he installed Huper Optik and a number of other high quality films. I scheduled an appointment to come in.

At the appointment, the installer showed me the Huper Optik film and noted its shiny appearance. I was surprised at this because online I read that the HO wasn't shiny. He said that there were differences between the HO residential film and automotive film, and probably much of what I'd read online was regarding the residential film. The installer then looked carefully at the large curved rear window of the car and determined that the curvature was so great that he wouldn't be able to use the Huper Optik ceramic automotive film because he couldn't shrink and install a single piece.

I was surprised at all this. I've never pretended to be an expert at anything after an hour of looking online, so I asked him for his recommendation if what I wanted was the lightest possible tint that would be effective in helping the a/c to work better (that is, I wasn't there to tint the windows because I liked the look of tinted windows).

He recommended Geoshield DMC40 ceramic/dye film. He cut a piece and laid it on one of the door windows. It certainly was a visible (not clear) tint, but I thought it looked acceptably light.

It took him about three hours to do the car. Multiple attempts were made to get the rear window done because of its size and curvature. Clearly he put a lot of time and care into it.

When he was done, the first thing I noticed was that, with the tint on all the windows, the car was darker than I'd expected. The installer agreed.

But the second thing was that, around the inside of the rubber rear windshield seal, was a border of black tape between 1/4" and 1/2" wide. The installer said that this kind of old windshield had "no room for error" and that, try as he might, he couldn't get his fingers in place to stretch the tint perfectly down to the edge of the rubber seal, and the tape ("pinstriping" he called it) was an accepted method of hiding the gap that would otherwise show between the tint and the rubber. He showed me a rear windshield on a more modern car with a black border, and explained how this provided "room for error." I said that I didn't like the look of the black tape, and he agreed, and said that if I could have the windshield removed, he could tint right to the edge.

Unfortunately when I looked into it, the rear windshield on this car appears to be NLA, the rubber seal is $120, and the two chrome strips that spread the rubber seal are, incredibly, $380 apiece. I've pulled these strips out of parts cars, and they tend to bend up and never lie flat after that. In other words, the risk in pulling the rear windshield out is pretty high.

The installer charged me $280, which I consider an extremely reasonable sum for a very large amount of work. He has offered to redo anything I'm unhappy with, but other than removing the rear windshield, he doesn't have an option for making the rear window film installation better (getting rid of the tape).

Although the windows are noticeably darker than I wanted, I think I can live with it, especially since the only choice seems to be taking the film off.

If I had to do it over again, I should've left after finding that I'd misinterpreted what I'd read online about Huper Optik film and learned that I couldn't get a nearly clear film that would be effective.

That's the story. Here are my questions:

--IS there a nearly clear ceramic film, Huper Optik or otherwise, that could be used on my car with its highly curved rear glass?

--IS there a way to tint right to edge, or closer to the edge, of the rear windshield without pulling the glass out?

Thanks for any feedback.

June 5, 2010

LLumar air-80 blue.

This is a ceramic film and blocks out 43% of the heat, and as far as the edges go, they are really hard back glasses, but it should be able to be taken alot closer than a 1/2 inch, if not all the way to the edge imo

TintJunkie · June 5, 2010

You will NEVER get Huper to stretch around that back window...ever in one piece. There are very few ceramics (if any) that will tolerate that kind of shrink. I think you brought it to a guy that was honest, however, if it was me and I knew I couldnt hide the film in the gasket (by possibly notching the gasket) I would have came to you and told you what would have to be done. Other than that, I think the guy really knows what he is doing, and sounds like a good person to do biz with.

Yes, the film could be hidden in the gasket, but the gasket would have to be notched out to hide the film. Think of a "V" cut into the gasket where it meets the glass. However, it is very difficult to shrink glass without a border. In order to shrink that window, one needs to move the film down off the gasket to shrink the top, then move it up to shrink the bottom, then lay the film to cover the glass and do a final cut. The inside is "shorter" side to side and )usually) top to bottom than the outside, so the installer can trim the film to the gasket on the outside, and overlap the gasket (after notching) on the inside.

The best way to make the window look like you want it is to have it removed. Also remember, any film, no matter what technology used to make it, will be better than nothing at all. There is no such thing as clear film that rejects a lot of heat. Huper is the closest to it, but its shiny.

lostinbama · June 5, 2010

:thumb good answer!

I'm getting to where I hate tinting old vehicles just for this reason. I do some work for a old car restorer/hot rod guy and he calls me after the windows are out of the car. Much easier to get a flawless install without the old crumbly gasket screwing things up...

June 5, 2010

Thanks for the replies guys. It's enormously helpful.

So one more question... V-Kool? Is this really a nearly clear film that blocks 99% of the UV and 70% of the heat? Can it be fit to my big curved rear windshield? Or does this whole thing about "clear films" really apply only to products for flat residential glass? I can't find any installers in my area who handle it.

I'm just a consumer trying to separate the wheat from the chaff. I have nothing but respect for the installer who did the work; I'm just sanity-checking the information and seeking contrary opinions.

TintJunkie · June 6, 2010

V-Kool and Huper are both made in the same plant, with the same machines. I think VKool does have an auto line, but you will run into the same problem with shrinking. These films, when exposed to prolonged heating by a heat gun, tend to "ghost" up. It will leave foggy patches where the film was exposed to the heat, and ultimately look like crap.

Im sorry, you have a difficult back window to shrink, and should consider going with a high quality metalized film or dyed color stable film at a very low VLT. The color stable films will be very non reflective, and the metalized films will be just slightly more reflective. Do some research on low VLT films yielding the highest heat rejection...again, good luck. :bs

June 6, 2010

There are very few ceramics (if any) that will tolerate that kind of shrink.

LLumar AIR 80 BL, CTX & Formulaone Pinnacle will.

They are in a minority based on the quote above.

Edit:

At the appointment, the installer showed me the Huper Optik film and noted its shiny appearance. I was surprised at this because online I read that the HO wasn't shiny. He said that there were differences between the HO residential film and automotive film

I've seen Huper 30 on glass and it looks reflective, but the lighter versions do not. When it comes to Huper C30, 40, 50, they are used for home and auto, even Residential Drei makes it on car windows so that line was

IMO

June 6, 2010

Thanks for the replies guys. It's enormously helpful.
So one more question... V-Kool? Is this really a nearly clear film that blocks 99% of the UV and 70% of the heat? Can it be fit to my big curved rear windshield? Or does this whole thing about "clear films" really apply only to products for flat residential glass? I can't find any installers in my area who handle it.

I'm just a consumer trying to separate the wheat from the chaff. I have nothing but respect for the installer who did the work; I'm just sanity-checking the information and seeking contrary opinions.

V-Kool does not block 70% of the heat. VK-70 is more like 55% depending on the glass type.

Complex stacked films and some multi-layered films are hard to shrink and can't be installed on some vehicles.