lexan windows with original rubber weathering

[scott.k]

Hello,
I am planning on putting lexan windows into the rear and quarters on my 911 sc with original rubber weathering. i will use aluminum strips on teh back window, but i would like the lexan to rit in the rubber as snug as the glass

What thickness should the lexan be?, 1/8"?, will that fit in the rubber?


thanks
scott

[scott.k]

or do people wrap something around the edges of the lexan so it sits more snug in the rubber?

thanks

[cgarr]

We used the original rubber on all the windows and 3/16 lexan.

[NOLAsc]

Originally Posted by cgarr

We used the original rubber on all the windows and 3/16 lexan.

Sometimes, there's a little drool.

[scott.k]

Originally Posted by cgarr

We used the original rubber on all the windows and 3/16 lexan.

Thanks for the help.
THat car is amazing, by the way.
-Scott

[scott.k]

I have one more question. with lexan, it wont take the same shape (bend) as the rear windshield as much, right? so it should be the width of the rear window opening/ space rather than the width of the rear window (including the curving)?

heres an attempt at making that more easily understandable. the lexan wont flex like the rear glass is, correct? say that windshield looks like a "C" because of its curvature when its lying on the ground (a bit of an exaggeration but you get the point). do you want the lexan to be the length between the two tips of the "C" shape, or the full length if you were to draw with a marker on the glass?

Thanks
Scott

[MrPerkles]

I used 4mm lexan with 993/964 seals and clamped it to the original glass so it matched the curve.I also did my door window wind up glass but would use 5mm next time as 4mm flexes to much for a road car in this area
the front & rear 1/4s and rear screen fit with no leaks HTH

[Mahler9th]

I have a seal and a piece of polycarbonate that can be used as a template. The polycarbonate is flat, and flat works just fine for a 911. My chassis is a '75.

As an alternative to polycarbonate, one can use Vivak.

[JP911]

I just did this project and used both the stock seals and trim. Lexan MR10 and cut it to shape (I was surprised how easy it was to work with). I went with 3/16" in the rear and the rear quarters. As others have said, the rear will flex into the shape of the stock glass.

[uncle_scott]

This has probably been covered, but how much weight are you dropping, and are people doing this on street driven cars, or track only?

[cashman]

You should use PC (eg, Lexan, Makrolon) for the windows. It is designed for that type of application. PETG (Vivak) is a clear substrate that technically would work but It is more of a point of purchase display product. Like acrylic (Plexiglas) on steroids or a 2-liter Coke bottle. It does not have as high impact as PC and will yellow quicker when exposed to UV. Since your going through the effort, use PC.

In the US, 3/16" is typically .177" thick and 1/4" is typically .220". You can get 1/4" at .236" but that is not what most plastic distributors stock.

[Flieger]

Originally Posted by Mahler9th

I have a seal and a piece of polycarbonate that can be used as a template. The polycarbonate is flat, and flat works just fine for a 911. My chassis is a '75.

As an alternative to polycarbonate, one can use Vivak.

Hey, is this you at Rennsport?

Porsche 911 #4 | Flickr - Photo Sharing!

[MrPerkles]

Originally Posted by uncle_scott

This has probably been covered, but how much weight are you dropping, and are people doing this on street driven cars, or track only?

mines a road/track car
door window glass not including 1/4 panels,3.2kg's pers side ,1.8kg's per side for the mechanism and winders

[Mahler9th]

Yes, that is me at Laguna in group 7 at RR IV, car #4. There were a few of us in Group 7 with cars that are registered for street use...

I have made these windows out of scratch-resistant polycarbonate and out of PETG, and have purchased one from a commercial vendor in PETG. PETG is much less expensive for DIY and works just fine. I have the PETG unit on in the picture above. Excellent optical clarity and easy material to work with.

I use 1/8 thick material in either case. No benefits of thicker material.

No issues in street driving, BUT I do not drive or race in the rain. If I did, I would modify the install slightly.

With a rubber seal, I do not think leaking would be a problem... it wasn't for me when I ran the rubber seal, based on washing the car.

[Flieger]

So yours have a hard polycarbonate coating? I do not think mine do. They are not cloudy but they are not as shiny as yours since they have small scratches all over them.

[uncle_scott]

Originally Posted by MrPerkles

mines a road/track car
door window glass not including 1/4 panels,3.2kg's pers side ,1.8kg's per side for the mechanism and winders

Wow 22 pounds total. That is a great savings. Definitely something to think about as I plan out my lightening attack on my Carrera I just picked up. I would imagine that the slightly thicker material might fit in the rubber seal slightly more snug which would lend itself better to daily driving in inclement weather. SLC has a great plastics warehouse, so this might be something I try out this winter just to test my hand at cutting and installing it.

Thanks for the info!

[Mahler9th]

The polycarbonate materials come in various types... and there are various types of scratch-resistant coatings.

My original window was installed with a rubber seal and flat polycarbonate and held up very well.

Several friends have the Spektr products frame and window and they appear to hold up well. Spektr actually use a shaped piece of plastic for their rear windows. They use heat to shape the plastic. A great product that is used by many folks.

Other companies sell just the windows and some of them are shaped, and/or have scratch-resistant coatings. Prices vary.

This year I made two frames, similar to Spektr's. One is made out of carbon fiber, the other from ABS plastic. The frame is lighter than the rubber by just a tad, and now I can easily remove the window for cleaning, et cetera. Plus I needed a project.

I bought piece of PETG/Vivak and used that in the CF frame for a while. I shaped it with gentle heat. Held up well. Now I have a flat, scratch-resistant polycarbonate window sitting in the ABS frame I made.

When you use a rubber seal, flat plastic is just fine. When you use a fiberglass frame, like what is available from Getty Design, flat plastic seems to work fine.

The frames I made encourage the use of a window with some shaping. Either polycarbonate or PETG can be shaped with heat, but I think PETG is easier to "heat form."

[strokher racing]

I just pulled the glass out of my 964 turbo to make new quarter windows and a new rear out of polycarbonate......I am not happy at all. The quarters weigh nothing! Talk about a total waste of time! I am heading to weigh them now. I feel sorry for people who pay the big bucks for lexan from a shop looking to loose weight from the rear and quarters

[javadog]

Porsche used 5mm glass in the front quarter windows and door windows. They used 4mm glass in the rear quarters. A glass rear quarter window weighs around 2 pounds 10 ounces. A 5mm plastic rear 1/4 window saves about 19 ounces and a 4mm one saves about 23 1/2 ounces.

JR