For those with Lexan windows, mostly the rear window

[BluDestiny]

Hey,

 

I was wondering how all you're windows hold up in day to day driving. I'm thinking about making one for my 280zx hatch, but I will be daily driving the car so I don't want it leaking, or cracking from stress.

 

I was thinking a nice coat of RTV on the inside and outside along with quite a few screws holsing it in should keep water out.

 

Please share your experiences.

 

Edit: whoops I thought it was plexi, just wrote the first thing that came to mind. Changed the Title.

Edited September 17, 2011 by BluDestiny

[mark]

If you do it use lexan not plexy glass. Imo lexan is not for a dd. It scratches easily and lights from the rear at night will be a pain.

 

I had a lexan front windshield in my race car but got rid of it because it scratched so easily. I still have the rear lexan on the car but it does not get driven at night.

 

With the sun behind me In the afternoon it can be difficult to see clearly.

[JMortensen]

Agreed, lexan scratches if you look at it wrong. I don't have any personal experience with the scratch resistant coatings, so that may be something to check out. It also discolors over time, and exposure to things like Windex are bad news, makes it cloud up.

 

If you're determined to use it and want your car to be watertight, you can put the Lexan into the stock weather stripping. I have a friend who did this on his 510 rear window, worked fine. He had to do some interesting bends on the straps to hold it in, but it wasn't that big a deal.

[johnc]

As mentioned above, it will scratcha nd haze easily. The scratch resistant coating helps extend the scratch free life of the lexan by about 50%. So, you'll go from one year to 18 months before it looks like crap, but you'll pay 100% more for the scratch resistance. You do the math.

[Driven5]

While I can't validate any concerns on long term durability from first hand experience, there are options to improve the longevity of polycarbonate (lexan) windows. An alternative to the scratch resistant coatings offered on the polycarbonate sheets is be to apply a polyester (mylar) film to the window, also referred to as a tear-off in racing, over the polycarbonate to act as a protective layer. I'm pretty sure that principle is largely responsible for how I am still able to see clearly through my long abused polycarbonate sunglass lenses. With proper care, I think this could be effective for an appreciably longer period of time on a rear window than a windshield. However I don't think that it would necessarily be a permanant solution either, thus the film likely will require some unknown frequency of semi-regular replacement varying on many factors regarding the cars use. Depending on the acutal required replacement frequency, this could certainly add up. I have personally also wondered if a urethane film (paint protection/clear bra) might similarly be used with reasonable success compared to a polyester film.

 

As was already mentioned, you'll probably want to avoid acrylic (plexiglass) as it can break into dangerously sharp shards in an accident.

Edited September 16, 2011 by Driven5

[thehelix112]

Driven5,

 

Thanks! I'd been wondering what the exact stuff they use was called for ages.

 

Dave

[mario_82_ZXT]

A friend has a hatch in his dd. It's been on there a few years, its slightly hazy but not too bad.

 

He's got 2 pieces of aluminum, I think channel, attached to the hatch and the lexan is riveted to those and the frame.

 

It leaks water too...

[Tony D]

Polycarbonate is used on Aircraft Canopies, and there are a plethora of care items to keep it 'optically perfect'---the last thing you want as a pilot is to look through the canopy and have hazed and distorted views of Bogeys at 4G's in a Split-S

[Driven5]

Actually acrylic is hands down the most common aircraft windshield/canopy material, due in no small part to its vastly superior scratch resistance and ability to have small scratches polished out. Of course window requirements for cars and airplanes can not be directly compared due the completely different operating conditions.

Edited September 17, 2011 by Driven5

[260DET]

The back window on mine is acrylic which was moulded over the stock glass and extended a bit all the way around so it could be bonded directly to the hatch. The moulded shape is curved which strengthens it considerably so no reinforcing is necessary. Sikaflex was used to bond it to the metal hatch flange, nothing else. I have done over 200kph in the car plenty of times with the drivers window partly open with no problems at all.