GT40s.com
MK-I  MK-II  MK-III  MK-IV  GULF  MIRAGE  J-CAR  LOLA
GT40s.com
Home Forum Gallery Support GT40s.com  
Register FAQ Advertisers Search Today's Posts Mark Forums Read

Go Back   GT40s.com > > >

Notices

The SLC Clubhouse RCR SLC Build Logs and Technical Questions

Reply
 
Thread Tools Display Modes
Old 28th June 2016, 07:49 PM   #1
Dan carter
Bronze Supporter
United States
 
Join Date: Jun 2014
Location: Georgia USA
GT40: SLC
Posts: 485
Rear window lexan

Has anyone observed any yellowing with the rear window? I assume it is lexan, which has several additives, and UV protective to reduce any yellowing.

What experiences do we have so far?

Thanks
Dan carter is offline   Reply With Quote
Old 28th June 2016, 08:32 PM   #2
StuM5
2 Tenths
Australia
 
Join Date: Mar 2007
Location: Sydney
GT40: SLC/LS3/Ricardo
Posts: 207
Re: Rear window lexan

Hi Dan!

I've done nearly 9,000 miles on my SLC here in Sydney, we have very harsh sunlight/UV here in Aust and my rear window and side windows are all fine.

cheers Stu
StuM5 is offline   Reply With Quote
Old 28th June 2016, 08:36 PM   #3
Dan carter
Bronze Supporter
United States
 
Join Date: Jun 2014
Location: Georgia USA
GT40: SLC
Posts: 485
Re: Rear window lexan

Thanks Stu

I presume no impact from engine heat either.
Dan carter is offline   Reply With Quote
Old 28th June 2016, 11:53 PM   #4
sswartz's Avatar
sswartz
Lifetime Premier Supporter
United States
 
Join Date: Mar 2015
Location: Boston
GT40: SLC/LS7/Ricardo
Posts: 249
Re: Rear window lexan

Dan, it's not Lexan -- Lexan is a brand of polycarbonate and Superlite doesn't use it. I know at some point Superlite switched to a superior hard-coated polycarbonate which is more scratch resistant. I'm not sure when they made that switch or if it would have any effect on yellowing.
sswartz is offline   Reply With Quote
Old 29th June 2016, 02:15 AM   #5
StuM5
2 Tenths
Australia
 
Join Date: Mar 2007
Location: Sydney
GT40: SLC/LS3/Ricardo
Posts: 207
Re: Rear window lexan

Mine is definitely hard coated polycarbonate. Perhaps that's why it doesn't yellow.
No impact from engine heat
StuM5 is offline   Reply With Quote
Old 29th June 2016, 07:43 AM   #6
Dan carter
Bronze Supporter
United States
 
Join Date: Jun 2014
Location: Georgia USA
GT40: SLC
Posts: 485
Re: Rear window lexan

Great info

I'm trying to get smart on how to care for this product.

Being a super hard coated poly, can we assume the cutting and care is the same as any poly?

I have to trim my rear window, how did you cut yours?

Thanks
Dan carter is offline   Reply With Quote
Old 29th June 2016, 11:09 AM   #7
PeteB's Avatar
PeteB
10 tenths
United States
 
Join Date: Aug 2012
Location: Dayton, OH
GT40: SL-C
Posts: 1,007
Re: Rear window lexan

Quote:
Originally Posted by Dan carter View Post
Great info

I'm trying to get smart on how to care for this product.

Being a super hard coated poly, can we assume the cutting and care is the same as any poly?

I have to trim my rear window, how did you cut yours?

Thanks
Tips for cutting the plexiglass rear window?
PeteB is offline   Reply With Quote
Old 29th June 2016, 12:13 PM   #8
Dan carter
Bronze Supporter
United States
 
Join Date: Jun 2014
Location: Georgia USA
GT40: SLC
Posts: 485
Re: Rear window lexan

Thanks Pete

I note the terms plexiglass and polycarbonate get used interchangeably in that 2014 discussion.

I gather that the same cutting technique apples to either product.

Is this the case?
Dan carter is offline   Reply With Quote
Old 29th June 2016, 12:49 PM   #9
molleur's Avatar
molleur
Bronze Supporter
United States
 
Join Date: Mar 2008
Location: Florida
GT40: SL-C LS1/930LSD
Posts: 7,097
Re: Rear window lexan

The trade name for polycarbonate is Lexan.
Plexiglass is an acrylic and different.
__________________
Happily deplorable!

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
molleur is offline   Reply With Quote
Old 29th June 2016, 04:50 PM   #10
sswartz's Avatar
sswartz
Lifetime Premier Supporter
United States
 
Join Date: Mar 2015
Location: Boston
GT40: SLC/LS7/Ricardo
Posts: 249
Re: Rear window lexan

Dan,

I added a new page to manual here:

Common Manual: Working with Polycarbonate

Since it's a generic topic it was added to the common manual. Therefore a logon/password is not required to view it.
sswartz is offline   Reply With Quote
Old 29th June 2016, 04:55 PM   #11
Dan carter
Bronze Supporter
United States
 
Join Date: Jun 2014
Location: Georgia USA
GT40: SLC
Posts: 485
Re: Rear window lexan

Thanks

Poly it is.......
Dan carter is offline   Reply With Quote
Old 29th June 2016, 08:44 PM   #12
Scott R.
Guest
United States
 
Join Date: Apr 2015
Location: Beaverton Or
GT40: SL-C
Posts: 1,041
Re: Rear window lexan

It is my understanding that the scratch resistant coating material cannot be formed. If it is, maybe the curve of the rear window is slight enough to allow for it?
Scott R. is offline   Reply With Quote
Old 29th June 2016, 10:44 PM   #13
Mark Clapp's Avatar
Mark Clapp
Bronze Supporter
United States
 
Join Date: Oct 2001
Location: Kansas City, Missouri USA
GT40: Mark I (South Africa)
Posts: 694
Re: Rear window lexan

Hi Guys, I cut even curved polycarbonate with 36-teeth-per-inch fine metal cutting blades in my saber saw. I use Bosch brand, which are available in packs of 4-5 from Lowes. The edges come out almost polished with no roughness or "heat boogers" (technical term). When you're done you just run your fingers along the edges and all is clean. The keys are: (1) the very fine tooth blade and (2) cover the foot of the saw with some tape and just glide the saw over the plastic without pressing down so as not to scratch or mar the plastic. Also, keep the protective film on to keep from scratching the plastic.

Mark Clapp
__________________
Kit Car Centre Mk I (South Africa)
Mark Clapp is offline   Reply With Quote
Old 30th June 2016, 09:10 AM   #14
molleur's Avatar
molleur
Bronze Supporter
United States
 
Join Date: Mar 2008
Location: Florida
GT40: SL-C LS1/930LSD
Posts: 7,097
Re: Rear window lexan

And, go slowly to prevent heat buildup and melting.
__________________
Happily deplorable!

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
molleur is offline   Reply With Quote
Old 30th June 2016, 01:28 PM   #15
glarrivee's Avatar
glarrivee
A Tenth
United States
 
Join Date: Jan 2003
Location: So California
Posts: 147
Re: Rear window lexan

Also never use flathead screws/bolts. They cause hoop stress and will eventually crack the polycarbonate. Use a bolt that puts the material in compression like a pan head bolt. Drill oversized holes and use washers to distribute and cushion localized stress and compensate for expansion and contraction of the polycarbonate as the temperature changes.

Last but not least never ever ever ever use thread locker on the bolts. They are not compatible with polycarbonate and will eventually craze and crack the material.

When making cuts always try to leave a radius (even a 0.020" radius is a big help) on all inside corners. polycarbonate is very notch sensitive and always use good support along the edges.
__________________
I have GT40 dreams on a Mini pocketbook
glarrivee is offline   Reply With Quote
Old 30th June 2016, 04:29 PM   #16
molleur's Avatar
molleur
Bronze Supporter
United States
 
Join Date: Mar 2008
Location: Florida
GT40: SL-C LS1/930LSD
Posts: 7,097
Re: Rear window lexan

Great tips Gary!
__________________
Happily deplorable!

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
molleur is offline   Reply With Quote
Old 30th June 2016, 07:31 PM   #17
EFNFAST
I Have No Life
Canada
 
Join Date: Jan 2009
Location: Here
GT40: 917, SLC, Cobra
Posts: 2,840
Re: Rear window lexan

it amazes me so many people countersink their windows ... that's gotta lead to cracky-cracky down the road.

for my windshield i just used 4 #6 screws w/ washers and powercoated them a wrinkle black color so they don't look like cheap-ass machine screws
EFNFAST is offline   Reply With Quote
Old 8th July 2016, 10:57 PM   #18
Cam
Cam MacIsaac's Avatar
Cam MacIsaac
7 Tenths
United States
 
Join Date: May 2009
Location: Dallas, TX
GT40: Sold 911 fo SLC
Posts: 755
Re: Rear window lexan

Hmm. I countersunk all my windows 8/32 in the rear clam, doors and windshield. I've not seen a single crack in any of them in 14k miles. I think the trick is Fran recommended using black nylon screws. A huge amount of give. My last track event we ran counterclockwise on Eagles Canyon. The front was getting airbourne on bad pavement in turn 8 for four sessions x 8-10 laps. Still no cracks... no yellowing either since 2009.
Cam MacIsaac is offline   Reply With Quote
Old 9th July 2016, 05:50 AM   #19
Dan carter
Bronze Supporter
United States
 
Join Date: Jun 2014
Location: Georgia USA
GT40: SLC
Posts: 485
Re: Rear window lexan

Has anyone ever tried using standard windshield butyl glue to set the Windows? It's flexible, water tight, and if you ever remove the "lexan" it should come off with a standard windshield removal tool.

Thoughts?

Dan carter is offline   Reply With Quote
Old 9th July 2016, 09:37 AM   #20
PeteB's Avatar
PeteB
10 tenths
United States
 
Join Date: Aug 2012
Location: Dayton, OH
GT40: SL-C
Posts: 1,007
Re: Rear window lexan

Just a thought - If you're planning to do any open track events, many of the organizations require the windows to be rolled down so you can waive people by. On an SLC that means either removing the windows or having a hole in the window to stick your arm through. Windows held on with screws are easy to remove for the track.
PeteB is offline   Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Display Modes

 
Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On

Forum Jump


All times are GMT -4. The time now is 10:14 PM.